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Nor-140 User Manual - Campbell Associates

1. Norsonic Nor140 Instruction Manual The Building Acoustic Engineering method mode allows measurement of building acoustic parameters according to the ISO 140 series of International Stand ards Measurements are made in one third octave bands and the results are reported for each band as well as frequency weighted values according to ISO 717 1 and ISO 717 2 The mode is entered by pressing MODE and select 4 BuildAc Press 1 or 2 for selecting the measurement of either airborne or impact sound insulation accord ing to the survey method Press 3 or 4 for selecting the measurement of either airborne or impact sound insulation according to the engineering method For measurement of fagades use Airborne as de scribed in sections covering Fa ade insulation At any stage except in result display the instru ment may be brought back to normal operation by pressing MODE again and select the mode Normal NY You have the choice to start measurement Ay within the Building Acoustic mode or to make 2 level measurement in Normal mode rever beration time measurements in Reverberation mode and store the result and later retrieve the results in Building Acoustic mode for calculating the final result 116 Chapter 23 Building Acoustics If you want to start over again or change from Air borne to Impact task you have to enter through the general MODE menu Terms and definitions for airborn
2. Ms Y S 2 Keeping track of the measurement mode A the file was stored in The different modes E are indicated in the file list as follows Recall INT 0001M SETUP STNDRD 0002M 060823 060824 All file names i e file numbers have a letter as suffix This letter indicates the measurement mode Mw Ss means frequency analysis but no profile L means that the file contains a simple global measurement but no frequency analysis and no profile means a multispectrum measurement P means a measurement made in sound power mode R means a reverberation time measurement T means a profile measurement with or without a frequency analysis means Building Acoustic measurement means a STIPA measurement f means a FFT analysis Norsonic Nor140 Instruction Manual Clearing a single file To clear a single file 4 Press DEL Make sure that the file to be cleared is selected i e highlighted shown as white text on a black background Press the ENTER key You will now be prompted to confirm your action However as default the cursor is positioned on the cancel field to avoid erasing the wrong file Use the cursor keys to move the cursor to cur file and press ENTER again The file is now deleted Clearing folders or the entire memory To clear a folder If the SD card Press DEL Select it using the cursor keys and press ENTER You will now be prompted to select between clearing t
3. INSTRUCTION MANUAL A sound level meter with built in real time analyser capabilities complying with international instrument stand ards Parallel octave filters are stand ard optional in some markets but he impressive list of optional exten sions include third octave filters and statistics in every frequency band multispectrum reverberation time measurements and recording for the measured sound The instrument log evel vs time optional and when it i equipped with multiple time constan and the enhanced profile extension a multitude of functions is logged simul aneously The more than 120dB dy namic range eliminates the need for range setting A large memory SD card and high speed data transfer rates complete a user friendly solution E S S S nor140 SOUND ANALYSER NN Norsonic SOUND ANALYSER Nor140 User Guide December 2008 Edition Im140_1Ed3ROEn Correspond to internal version 1 4 Norsonic is a registered trademark of Norsonic AS All other brand or product names are trademarks or registered trade marks of their respective companies Every effort has been made to supply complete and accurate information However Norsonic AS assumes no responsibil ity for the use of nor for the consequential damages of the use of this information and or the instrumentation described herein Furthermore Norsonic AS assumes no responsibility for any infringement of
4. Spectral Measurement dune SSPL 8 running networks NS Z 0 4 Datum lower applied 247 2 end of bar raph Measured wervcs graph values NM N Y Going to measure very high levels Ay As an optional extension the Nor140 is able F to measure very high sound pressure levels without changing the microphone cartridge see High levels in the Technical specifications for details Instruments with time profile installed If your instrument has the time profile installed and you don t require it you should set the resolution to the same value as the duration to keep the instrument from logging the level as a function of time Setting the time constant If your instrument is not equipped with the optional extension 5 parallel time constants you may want to specify the time constant to be used in the measurement The time constant is used for the SPL the Lmax and the Lwin measurements but neither the Leg the Le nor the Leeax makes use of it The exceedance level La always apply the F time weighting and is independent of the setting To set the time constant press the TC key until the required time constant appears in the display To see this be sure to operate the FUNC key until any of the functions SPL the Lmax or the Lun appears in the display first If your unit is equipped with multiple time constants you need not bother with this Instruments with multiple time constants Instruments equipped with multipl
5. 26 0dB corresponding to a microphone sensitivity of 5OmV Pa For voltage input the level OdB then cor responds to 1uV Typical values for the self noise are 5 aB lower than the values stated The noise levels are measured without light in the display Noise measured with 18 pF microphone dummy and microphone preamplifier Nor1209 averaged over 30 s of measurement time Spectral weighting functions A weighted 13 dB C weighted 15 dB Z weighted 25 dB Filter bands 1 3 oct 6 3 Hz to 250 Hz 10 dB option 1 3 oct 315 Hz to 20 kHz 5 dB option Noise measured with Nor1225 microphone and pre amplifier Nor1209 averaged over 30 s of measurement time Spectral weighting functions A weighted 18 dB C weighted 22 dB Z weighted 30 dB Filter bands 1 3 oct 6 3 Hz to 250 Hz 15 dB op tion 1 3 oct 315 Hz to 20 kHz 10 dB option Noise measured with the input terminal on the sound level meter short circuited to ground averaged over 30 s of measurement time Spectral weighting functions A weighted 10 dB C weighted 10 dB Z weighted 15 dB Filter bands 1 3 oct 6 3 Hz to 250 Hz 0 dB op tion 1 3 oct 315 Hz to 20 kHz 7 dB option Field calibration The recommended sound calibrator for verification of the sensitivity of the sound level meter is Norsonic Nor1251 with a nominal sound pressure 114 0dB at 1kHz In order to compensate for effects due to diffrac tion around the microphone we recommend adjustin
6. Norsonic Nor140 Instruction Manual Using a previously measured spectrum Select one of the four possible Reference curves as indicated above press the RECALL key and use the normal memory operation to choose any previously saved measurement as the new Reference Spectrum By confirming the selection with the ENTER key the stored Leq values from the selected spectrum will be entered as the new Reference Spectrum In case a measured 1 3 octave spectrum is chosen as a Reference Spectrum for a 1 1 octave comparison the 1 3 octave spectrum will be re calculated into a 1 1 octave spectrum automatically Choosing a previ ously measured 1 1 octave spectrum for a 1 3 octave comparison will produce an error message File data has wrong bandwidth Entering a new Reference Spectrum manually Select one of the four possible Reference curves as indicated above use cursor keys to move the field in dicator to the first desired frequency band and key in the correct value for this band using the numerical keys Use the cursor keys to move the field indicator to the next frequency band and key in the desired value for this new band Continue this operation until all de sired frequency bands are entered Itis NOT required to enter values for all bands Only those bands which have a value entered will be dis played on the graph Hence the user has full control of which frequency bands of the Reference Spectra that should be visible 85
7. 00 00 05 rt 00 00 05 Es n 060825 a 0 05 me 08 49 07 zt Leq s0 SSPL s A 44 1 E A 42 9 C A 12 1 C A 12 9 ws vs If you retrieved a stored setup this is now available for use if you retrieved a stored measurement this is now available for inspection The fact that you have re trieved something from the memory is reflected in the text line appearing at the top of the display see Fig Standard set up Some standard set ups are delivered with the instru ment You may use one of these set ups as a start ing point for making your own version The standard set ups are placed in a folder marked STNDRD see figure below A description of the different set ups is found in the table on the next page If a set up for a particular mode is loaded the instru ment is automatically set to the corresponding mode of operation independent of the previous mode Clearing files and folders in the memory To delete files and folders in the directory Press the clear key The display will now produce the CLEAR menu In order to successfully locate the files and folders you want to load you must apply the procedures discussed in Retrieving stored setups and data including the side bar on this page The menus for clearing files folders and the entire memory Clear INT CONFIRM CUR FILE Clear INT SELECT CUR DIR CANCEL Ms ALL DATA RESET CANCEL
8. 200 level values per second When the levels are the response to a short acoustic impulse the sample will represent the square of the filtered impulse response averaged over the time span of 5 ms The sequence of such samples are stored during the measurement Norsonic Nor140 Instruction Manual and processed as soon as the measurement is ended The backward integration is started from the cross point between the decay and the background noise The back integrated curve can now be obtained with a time resolution of 5 ms for each filter band Samples between 5 dB and 25 dB below the maximum are used for the calculation of T20 by application of regression In a similar way values between 5 dB and 35 dB are used for calculating the T30 value The instruments automatically compare the low est levels for the calculation with the estimated back ground level and gives warnings if the distance is not sufficient When the reverberation time is measured with abrupted noise from the internal noise generator the level is logged with a time resolution of 5 ms from the time for switching the noise off A least square fit re gression method is used for fitting a linear decay which is used for the reverberation time calculation Levels between 5 dB and 25 GB relative to the level before the noise was switchedoff are used for calculating T20 In a similar way levels between 5 dB and 35 dB are used for T30 calculation Ref 1 Schroeder M R
9. 86 Chapter 18 Reference Spectrum Editing a selected Reference Spectrum Use cursor keys to move the field indicator in row with the frequency band to be edited Use the INC and DEC keys to adjust the value in 0 1 dB steps or use the numerical keys to enter the desired new value Al ternatively use the DEL key to clear the value If the values from one or more bands are deleted the Reference Spectrum indicators for these bands are NOT presented in the graphical display Comparison between reference and measured spec trum A preview is selected E 90 16 125 1k 8k AC APRW 10 0 05 C Leg 74 5 A pre weighted Reference Spectrum The Reference Spectra saved in the instrument are always stored with as unweighted values However if the A pre weighting display feature is used during the comparison both the displayed Reference Spectrum and the measured frequency spectrum will be pre weighted Go NoGo Quality Control feature The Reference Spectrum feature may be used to give a Go or a NoGo output signal in quality control ap plications This additional feature is found in the lower part of the Freq Mode menu as the QC setting There are three selections for the QC feature Off No Go NoGo comparisons are made On The Go NoGo comparisons functions con tinuously before during and after the measure ment End The Go NoGo comparisons functions only after the measur
10. T reverberation time s To reference reverberation time equal to 0 5 s k reverberation index dB Lar standardised impact sound pressure level dB L normalised impact sound pressure level dB V volume of the receiving room m Ao reference absorption area equal to 10 m The relations between the quantities are given by the following equations ke T Norsonic Nor140 Instruction Manual The values are calculated for each frequency band For Lirand La a single number value is also calculated The value corresponds to the 500 Hz value for the reference curve after shifted it in accordance with the method specified in ISO 717 2 Survey and engineering method Survey measurements according to the ISO 10052 standard are made in octave bands Option 1 Octave frequency analysis is therefore required in addition to Option 11 The procedure described in the Internation al standard specifies how to measure sound insulation by measuring levels in octave bands and estimating the acoustic absorption reverberation time Service equipment sound is measured in the normal mode of operation Engineering method measurements are made accord ing to the standards ISO 140 4 Field measurements of airborne sound insulation between rooms ISO 140 5 Field measurements of airborne sound insulation of fa cade elements and facades and ISO 140 7 Field meas urements of impact sound insulation of floors are made in one third octave band
11. Enter source coding With the enhanced profile option optional extension 7 you may tag or code sources as they happen A one digit code which appears in the display as 1 4 is entered to later serve as an identification of the type of noise This can also be referred to as adding a marker to the Measurement What were these impulses caused by E i 1 0 A eq 39 6 Mk Example In a traffic noise measurement a bus pass ing may be identified by the digit 1 while trucks may be identified by 2 unexpected vehicles by 3 etc In the profile display the markers appear as dots or lines below the graph If you move the time cursor onto such a dot the marker type i e its number will appear in the display During a measurement adding any of the markers 1 2 and 3 will assign the corresponding marker number to the current period only When you press marker number 4 however the marker will stay on until the key is pressed again The marker will therefore be assigned to the current period plus all consecutive periods until the marker again is deactivated This marker type is often referred to as a toggle marker as opposed to the single marker which is the other type A typical application for a toggle marker is to mark out intervals of particular interest The keys to use The keys used to enter the markers are PRINT marker 1 MODE marker 2 CAL marker 3 and EXIT marker 4
12. Key in the value or use INC or DEC to modify the dis played value External trigger Set External to ON by the use of the INC or DEC keys if you want to enable triggering by an external signal to the digital input terminal After pressing the START key the instrument will start waiting for an externally supplied binary voltage signal 3 3 volt CMOS The signal has to be applied to DI 1 pin no 8 on the gener al O socket See the specification section for further information Level above trigger Set the level triggering ON by the use of the INC or DEC keys if you want to enable triggering by a level A record of the sound will be started as soon as the level Record trigger Level above Minimum duration the level must stay below the threshold to terminate the record Pre trigger i Trigger threshold Record in the specified network or filter band is above a speci fied threshold In this way a noise event may initiate a record The selected main time constant F S or l is used for the level triggering function While the cursor is on the field for level triggering press 1 for setting the level and frequency weighting for the trigger point The field below Threshold indicates the sound pressure level needed for triggering Modify the value by using the INC and DEC key on the right side of the display or key in a numeric value followed by pressing ENTER The frequency weighting may be one
13. New Method of Measur ing Reverberation Time J Acoust Soc Am vol 37 1965 pp 409 412 Excitation signals Excitation for the integrated impulse response method may be any impulsive broadband source with suit able low directivity This may be a pistol an exploding paper bag or an exploding balloon capable of creat ing enough sound energy in the frequency range we need Sometimes the requested frequency range has 97 98 Chapter 21 Reverberation time measurements to be covered by using more means for the excitation a paper bag produces a lot of low frequency energy and a pistol mainly higher frequencies An advantage of using impulse excitation is that you don t have to drag heavy loudspeaker amplifier com binations with you In addition you will be able to rely on battery operation alone with no need for mains volt age By using noise excitation through a loudspeaker you will more easily verify proper levels and directional characteristics of the source When the interrupted noise method is applied you have to use the signal from the optional internal noise generator Option 10 Feed the signal to a suitable power amplifier and loudspeaker The power amplifier Nor280 and the dodecahedron loudspeakers Nor250 and Nor270 may be applied Minimum reverberation time possible The frequency analysis in the form of 1 3 and 1 1 octave filters sets a lower bound for the reverberation times that can be measured Al
14. chapter 18 for details BUSY Output level is high 1 when the Go NoGo quality control feature of the Reference Spec tra is in operation see chapter 18 for details OVL Output level is high 1 as long as the instru ment detects an input signal above the opera tional dynamic range Overload Norsonic Nor140 User Guide RUN Output level is high 1 as long as the instru ment is in the Running status i e the Nor140 is making a measurement REC Output level is high 1 as long as the instru ment is making an audio recording of the input signal Some features in the instrument may force the digital output line into preset settings which avoid the user from using the above selection for one or more of the output lines The Nor140 has the following preset settings The microphone check feature is controlled from point 7 in the Misc menu found using the key sequence SETUP 1 Instrument menu 9 Misc par By turning ON the DO 3 setting the digital output line 3 will be permanently connected to the microphone check feature independent of any previous setting Turning OFF this feature will allow normal user setting of the DO 3 again The Nor1516 feature used for wireless operation during building acoustics measurement as part of the Nor1516 system is controlled from point 3 in the Misc menu found using the key sequence SETUP 1 Instrument menu 9 Misc par By turning on the Nor1516 feature inside the
15. e ntegrated averaged sound pressure level e Sound exposure level e Peak sound level e Exceeding level for F time weighted sound pres sure level cumulative distribution As an option the sound level meter may also simultane ously measure e Integrated averaged I time weighted sound pres sure level e time weighted sound exposure level e Taktmaximalpegel DIN 45657 F time response 5 seconds Takt Level distribution As an optional extension the instrument may be fitted to calculate the exceeding level cumulative level dis tribution for the F time weighted level The calculation is done for frequency weightings A and C or Z and for 1 1 octave or 1 3 octave filters if present and used in a measurement Class width 0 2 dB Number of classes 652 for levels between 10 dB above full scale 140 dB and 120 dB below full scale 10 dB The classes for the highest and lowest levels are extended to also include levels above and below respectively Sampling frequency for level 10 samples per second Display resolution 0 1 dB based on interpolation 154 Chapter 27 Technical Specifications Indication range The calibration of the instrument allows microphones with sensitivity in the range 84 dB to 15 9 dB rela tive to 1 volt pascal to be applied The corresponding display range for the indicated sound level is 50 dB to 180 dB Self noise levels The self noise is measured with the calibration set to
16. the processor is programmed to give priority to func tions related to global measurements time average discarding functions related to variation due to time and sound recording If the number of active functions is less than selected by the user a workload warning is presented on the display in the form of a W in the marker field on the display Norsonic Nor140 9 Instruction Manual N The options available The below list was complete and exhaustive by the time of printing of this User Y Option 0 Option 1 Option 2 Option 3 Option 4 Option 5 Option 6 Option 7 Option 8 Option 9 Option 10 Option 11 Option 12 Option 13 Option 14 Option 15 Option 16 Option 18 Option 19 N Guide However constant improvements will normally result in new extensions becoming available on a regular basis Check with your local Norsonic distributor or the factory for an update on this matter Limas Leg and L measurements according to German Standards 1 1 octave real time filters 0 5 16 000 Hz Reference spectrum comparison require option 1 1 3 octave filter bands 0 4 20 000 Hz require Option 1 Statistical calculations Parallel F S time constants Basic time profile mode Enhanced time profile mode require Option 6 Sound recording require Option 6 Reverberation time calculation require Option 1 Internal noise generator with white and pink noise signal cabl
17. 0 63 Mamas E E os PEPE HITA s Aaa y LLELLLL g 111 25 ECL Ltt tril E e116 ti tit f LLILESLLI TIE S 2 LITT iS Lt ttt ys 8125 PT iti is Litt rit E sheas PTT je AO HAH e s4 BI Ir pt ttt tt s S5 LLLLLLL 5 AH rd e Le3 i tT tit i LLLELLI is 8 NN EE HEEE 10 EM 125 IE 133 134 Chapter 24 Speech Intelligibility by STIPA The battery operated Nor140 sound level meter is placed in the position in the room where you want the speech intelligibility to be judged About 15 seconds after the start of measurement the STl value will be indicated on the screen of the instrument No cable is needed between the excitation and the instrument CIS The instrument will use the measured STI value and also present the speech intelligibility in an alternative scale called Common Intelligibility Scale abbrevi ated CIS This scale is according to the definition in IEC 60849 1998 02 Sound systems for emergency purposes It is a non linear relation between the STI and CIS value although both use 1 to indicate the best intelligibility and O for the poorest Units included in delivery Software option for Nor140 The STIPA calculation program is designated as op tion no 13 on the Nor140 The option may be activated when the instrument is first delivered or installed on the sound level meter at a latter date Please contact your local Norsonic dealer or the factory if you want your instrument upgraded wit
18. Calibration is a vital point ensuring that your meas urements are correct for the purpose Therefore a separate chapter has been devoted to this subject How to measure with the Nor140 is described in the following chapters The first measurement description outlines the use of the Nor140 as a simple sound level meter The second description extends the descrip tion to also include frequency analysis Some general information on the basic use of the instrument appears in both these chapters to avoid page riding Hence if you read both chapters you will find a repetition of certain issues The third of these chapters deals with the basic level vs time extension If you are going to make level vs time measurements you should read the two pre ceding measurement description chapters first to get a good understanding of the instrument s behaviour The enhanced version of the level vs time mode is described in the following chapter but we do recom mend that you read both the L t chapters to get a good overview Multispectrum feature allows the level vs time to log complete spectra as an f t This feature made it natural to include reverberation time which has been granted its own chapter Separate chapters has be devoted to special measurement tasks like sound power measurements building acoustic measurements speech intelligibil ity measurements and narrowband measurements by Fast Fourier transformation techniques
19. RES pod A A 0 01 AAA AAA 0 01 EA E 0 01 p The level above which trigger will take place provided that a level transition takes place is shown as a horizontal line This line is always located 30 dB below the display top scale To move the line up and down what you do is to change the display top scale use the INC and DEC keys The position of the graph cursor the frequency cursor determines the frequency band to be used as trigger band The instrumentisin iniii Display Reverberation top scale 16 125 1k _8k AC 40 0 08 A Leq 87 4 1 0k Hz Big Ww time mode e Set the excitation type Ex type to NOS e Set the time duration for the excitation Ex time The time is given in seconds The value should be at least equal to half the reverberation time to be measured Press ENTER to leave the menu The selected topscale has no influence on the meas urement in this mode of operation Press the START key The instruments switch on the noise for the selected excitation time and present the W mark The logging of the level starts when the noise is switched off and the run indicator is displayed The instrument will measure for 10 seconds and count down to O to indicate how much is left of the Norsonic Nor140 Instruction Manual measurement The acquired results are then pre sented as a table If you are measuring very short reverberation times you may terminate the
20. exist three possible configurations as shown in the Fig to the left The characteristic dimension do can be calculated from the following formulae Reference box on one reflecting plane l I de 2 JC 2 442 0 D O 3 Reference box on two reflecting planes do LP eg Reference box on three reflecting planes do 44 12 12 Hemispherical measurement surface The hemisphere shall be centred in the middle of the box consisting of the reference box and its images in the adjoining reflecting planes point Q in the Figs overleaf The radius r of the hemispherical measure ment surface shall be equal to or greater than twice the characteristic source dimension d and not less that 1 metre 104 Chapter 22 Sound power The radius of the hemisphere should be one of the following values in metres 1 2 4 6 8 10 12 14 or 16 Some of these radii may be too large to meet the environmental requirements given in ISO 3746 If so such large values shall not be used The environmental requirements state that the re flecting plane must not be of such a material or in such a condition that it radiates any appreciable sound en ergy due to vibration If the measurements are made outdoors over grass or snow covered ground the measurement distance shall not exceed 1 metre The general requirement is that the sound absorption co efficient of the reflecting plane shall be less than 0 1 over the frequency range of interest Als
21. microphone directly This holds as long as the system is linear and time invariant The measured response in the classical method based on noise excitation may in theory be described as a convolution between the excitation signal and the impulse response of the room However in the clas sical method with noise excitation the response is recorded directly and information about the impulse response is normally not known According to the Schroeder methods the results may be obtained from processing of the impulse re sponse itself 95 96 Chapter 21 Reverberation time measurements dB Lt dB L t dB Lyt dB L t Arh When a room has been ex cited by stationary white noise for a time sufficient to obtain stationary condi tions and the noise is thereafter switched off at the time t 0 the expected level at any time t 0 will be 1 W L t 310 x el ref t rea h t nt di Jr dt dB Lit n b where Calculation of reverberation time a based on the classical interrupted noise method and b based on impulse excitation For the classical method the mean decay may be obtained by averaging more decays By the use of the impulse method the expected de cay is calculated from the impulse response for the room W is a constant specifying the signal power per unit bandwidth of the excitation signal h t is the impulse response and calculation dB C is an arbitrary sel
22. older has the name of today s date and the files are numbered consecutively from 0001 and upwards This means of course that the maximum number of measurements per day is 9999 but this should be a limitation most people will be able to live with After all you are going to look through these files later as well aren t you f Storing the acquired data e Press the STORE key The display will show the folder and file number as can be seen from the Fig below All aspects of the memory handling are discussed in detail in Memory handling When data are stored Folder and file number of data stored The S indicates Stored 2 060824 00025 120 00 00 30 0 13 40 aa WS Printing out the results By connecting a printer to the RS232 interface the re sults can be output to a printer This is treated in detail in Making hardcopies Basic time profile measurements Instruments equipped with the optional extension 6 level vs time will be able to log the time profile like the classic level recorders used to do The time profile is measured by dividing a total measurement into smaller periods of time all hav ing the same duration Extension 6 allows the period length to be from 1 second and upwards in 1 second steps while the enhanced profile the optional exten sion 7 allows a period length from 50 ms and upwards in 25 ms steps but in 1 second steps above 1 second period length The
23. short lines for each individual frequency band The lines are of XOR type which means the lines will always be visible both with and without the actual overlayed bar graph See the figures on next page which shows exam ples with only the upper 1 1 octave and with both upper and lower 1 3 octave Reference Spectra activated Selecting the Reference Spectra Selection and or editing of the individual Reference Spectra are done in the Ref par sub menu This menu is opened by first moving the field cursor into the lower part of the Freq Mode menu and then using the 1 key to open the Reference parameter menu Reference curve selection menu Ref curve Upper1 1 Lower1 1 Upper1 3 Lower1 3 BWR BIBRWGS Upper 1 1 octave reference spectrum Upper 1 1 A oct Lea 31 5Hz 63Hz 70 0 125Hz 250Hz 76 0 500Hz 79 0 1 0kHz 82 0 2 0kHz 81 0 BIBRWGS Four Reference curves or spectra are stored within the instrument Upper 1 1 octave spectrum Lower 1 1 octave spectrum Upper 1 3 octave spectrum Lower 1 3 octave spectrum ROON Choose the desired Reference Spectrum by use of the numerical keys 1 4 A table will be presented contain ing either empty values for each frequency bana or the previously used values for each frequency band The individual values may be viewed by scrolling down wards and values for A C and Z weighting networks are available at the lower end of the table
24. the record length will have no limit This means that the record will last to the end of the measurement or until the storing device is filled Note that for event triggered recordings the speci fied duration will indicate the maximum duration the duration will otherwise be set by the condition for triggering Making a recording The start of a recording may either be done manually by pressing the RECORD key or if trigger option is in stalled by supplying an external trigger signal as from a remote button or based on a noise event detected by the instrument If the trigger option is not installed only the manual start of the recording without any de lay is available For a level triggered recording the recording will start during a measurement if the level in the selected network or filter band exceeds the preset level The length of the recording is selected as a part of the setup Recording mark Mark Norsonic Nor140 Instruction Manual From the trigger menu the delay in starting the sound recording can be set from 5 seconds up to 99 seconds This allows the recording to start up to 5 seconds before you pressed the record button or the trigger condition was fulfilled The recording file is automatically assigned to the current measurement When the level versus time display is selected the time for the recording will be marked adjacent to the time axes See figure below Setup for a recording
25. walls ceiling and floor in m Using reverberation time instead The classic definition of absorption area is the well known Sabine s formula v A 0 163 T in which V is the volume of the room T is the reverberation time of the room If your Nor140 is equipped with the optional extension 9 reverberation time measurements you may use this to calculate the absorption as follows K a 10log 1 4S A dB Kea 10log 1 4 SxT 0 163xV dB based on an actual reverberation time measurement Test room qualification requirements For the measurement surface in a test room to be sat isfactory for measurements in accordance with the re quirements of ISO 3746 the ratio of the sound absorp tion area A to the area S of the measurement surface shall be equal to or greater than 1 that is A S21 The larger the ratio A S is the better If you cannot meet this requirement a new meas urement surface shall be chosen This surface shall have a smaller total area but shall still lie outside the near field Alternatively you may improve the A S by adding sound absorbing materials to the test room If this does not help the test room cannot be used for ISO 3746 measurements Measuring the sound power The sound power calculation extension enables you to make a complete sound power measurement resulting in an Lw value the A weighted sound power level of Norsonic Nor140 Instruction Manual any test object in
26. 10 Making hardcopies Measured data can be output to a printer for docu mentation The instrument s print drivers support the following printer types e HP ThinkJet class of printers e HP DeskJet class of printers Diconix range of printers Most numerical printers The range of printers commercially available is an ever changing issue Therefore what was true by the time of design of the printer drivers used in Nor140 may not be true the day you read this Output from the Nor140 is purely numerical hence almost any numerical printer should be able to produce the output text on the paper Press SETUP 1 lt 2 to produce this menu IO Print I face RREA Passw OFF Baud 115200 Printer THINKJET Lang ENG 1 DigIO Norsonic Nor140 Instruction Manual The difference between the printers lies mostly in such things as character size and width which determines the number of characters that fit on a page Therefore we recommend that you make a few ex periments with the setup and your printer to find the driver that produces the best looking printouts Norsonic may provide a suitable cable between the instrument and the printer Setting up for printouts The setup for printouts is made in the IO Print menu To set up for printing 1 Press SETUP gt 1 Instr gt 2 IO Print 2 Set the serial interface port RS232 to ON set it to OFF when not used to save batteries set a baud rate your p
27. 100 1k 10k 100k Frequency Hz Effect of the windscreen Nor1451 for sound approaching the microphone from the front The diagram shows the frequency response for an instrument with windscreen relative to the response for an instrument without 162 Chapter 27 Technical Specifications The general i o socket Pin Signal Dir Remarks 1 DO 1 Out Digital output 2 DO 2 Out Digital output 3 DO 3 Out Digital output Reserved for calibration high calibration ON 4 RTS Out RS232 5 TXD Out RS232 6 PWR Out 3 3V max 10mA 7 RES In Reset 8 DI 1 In Digital input Reserved for ext trig 9 DI 2 In Digital input 10 DI 3 In Digital input 1H DO 4 In Digital output 12 DSR In RS232 ils RD In RS232 14 GND ref analogue signal 15 AC out Out Noise output Housing GND Instrument casing Signal output An analogue output from the internal signal noise generator Max output voltage 10 volt Output impedance lt 100 ohm The output is short circuit proof to GND and output current is in excess of 3 mA Gain accuracy at 1 kHz 0 2 dB Frequency response re 1 kHz 0 5dB for 20 Hz lt f lt 16 kHz Serial I O port RS232 port 9600 115200 baud The port may be switched off to reduce power consumption which should be considered if a cable is attached to the socket Digital inputs The digital input signals are 3 3V CMOS signals The voltage levels must be within 0 25V to 5 25V to avoid harmin
28. 5 Repeat 65 Resolution 38 Resolution time 38 Result 41 Presenting the L t as a table 41 Result tables 24 Reverberation time 94 Excitation signals 97 Impulse response method 98 Interrupted noise method 99 Minimum reverberation time possible 98 What is reverberation time 94 RPM 75 S SD card 57 164 Self noise compensation 91 Self noise levels 154 Serial interface 70 Service equipment sound pressure levels 128 Setups Mode dependent parameters 59 Storing a measurement setup 58 Signal out 75 Sound Power 102 About sound power measurements 102 Acoustic environment requirements 109 Measuring the sound power 111 Source coding 6 Specifications 151 Speech Intelligibility 131 CD for excitation 134 Development of STI 131 Excel sheet 134 How is STIPA measured 133 Selecting a loudspeaker for the excitation 136 Speech transmission index See Speech Intelligibility Start 22 Start a measurement 22 Statistics 20 Displaying the percentiles 25 User defined percentile 26 170 Appendix 1 Index STI 131 See Speech Intelligibility Development of STI 131 STIPA 131 See Speech Intelligibility How is STIPA measured 133 Stop 22 Resuming an ended measurement 23 The effect of pressing STOP before resuming 40 Storing 36 64 Automatic 64 Automatic storing 64 Manual 64 Repeat 65 Retrieving stored setups and data 62 Select the device for storing 58 Standard set up 62 Storage modes 64 Storing a measurement 60 Storing a measurement
29. A s EE IE Making Measures ee ic ee oc ta mE on cene n Dv isa Presenting the L t as a table ooooncoconocinonncccoocococococc cono nconnconn ccoo conan o ron nc cnn n ran n nano rca nennen nnns Enhanced time profile measurements eese eene nnne 42 Selecting which functions to lgg c ree ec tee dec ee E Ded t I Re deeds 42 Copyathe settitig to Bint MS iets Leere ti tete utet ret noes eu Dep EN UP LL M eret ts en eta acd 43 Setting the time resolution es sence soper e eed RE eed E RR Ended ERREUR 43 Measuring Inrenhanced Mode ns i RH Per eds 45 Displaying the T rictions measured icr cem ta rem e a e e ne PEG paa 45 Presenting the L t as a table ooooooconconnoniccocooccoocccooncconnconn cono ccoo nnnon nono n ccoo cnn nn non nn cnn naar naar ene ensi 45 Adding markers to a MeasureMentmccinnnnninnccnnnnnnnnnncnnnnn crac 46 T hie Keys to USO xo ptr ee mera Pare A Ia FER Tess 46 Other markers inserted by the instrument sssssssssssss eee 47 Instr umentrmarke rs have prioriby ecce hr ei et err eee aee dai 47 Marker OVEr VIEW sa sec tc i EP en RO i eu ttp tie es 47 Multispectrum measurements eeeeeeeeeeeee seen eene nnnn nent rnnt nnn niin nnn 48 Setting up for m ltispectrum ss ac oe e eee eee em eae c RERO 48 Units equipped with basic profile extension ssssssssss meme 48 Making multispectrum measurements emere a a E i 49 TiieresullbtableSs 5 O AO 51
30. Cr RD denna PC Ede Due 163 BOSQUES hrs ck eene tr ted titu MELLE EUM t e ML dte tudo da 164 SB titerface oc DOR E ORE E RR 164 SIDE ore lAa EA Ie 164 Data str A E N 164 Environmental CONOS rca cocos 164 Warm Up tiM eT o diz 164 SersitiVItV TOr VID RAUO Draenei ences o tid rain reto as attache aer He eet DL o Ml eres lara AO 165 Sensitivity tor magnetic til cima ce e a UR RIED RO SHIRE ate 165 A O Lia ett ELE fesses 165 Information for conformance testing ese Re etaed RR eee ER E 165 Appendix 1 O RAS 167 SOUND ANALYSER 2 Chapter 1 Introducing the Nor140 Introducing the Nor140 sound level meter No external modules The Nor140 comes with an extensive set of functions available in its basic version Many other functions are available as optional extensions The modular design of the Nor140 enables func tional expansion to take place when you need it and not necessarily at the time you purchase the instru ment All installed options remain in the instrument and there is no need for further loading of the options when used The functions available Even in the basic version the functions available with the Nor140 include the following e SPL The Instantaneous Sound Pressure Level e Luax The Maximum Sound Pressure Level e Lun The Minimum Sound Pressure Level e Lo The Integrated Averaged SPL e Le The Sound Exposure Level e Leak The Maximum Peak Level The spectral weighting functions A and C or Z weight in
31. Mk running Ws o 00 y ae Value at cursors position Pause and profile 120 emi Here the instrument is in pause mode Global acqui sition is halted but the profile is still acquiring data The thin line below the graph represents a marker associated with the periods acquired while paused The meaning of the line below the graph is given by the text Mk P which should be interpreted as Marker Paused to indicate that these data will not be a part of the global level assessment Norsonic Nor140 39 Instruction Manual Displaying the result tables To switch between A and display mode 0 05 C C or Z weighted values use Leg 56 0 TW FMax 582 Sound level meter ihe NETA key Fuin r 53 2 Bes 5 I 9 9 0 05 CF 99 0 53 5 Statistics is optional Units not configured for the German speaking markets will have tables without Leq Leql and Tmx5 6 zoa values To move the graph cursor Use P keys to Use diss to display use the db keys but not move to another another function during a measurement frequency spectral only after weighting network To scroll through the TAE table use the VA Profil gt rofile display x rj JU keys but only after a mode gt Pe measurement 40 Chapter 6 Basic time profile measurements v 1 lt No back erase in profile pause mode The b Ay resumption
32. Nor140 the digital output lines 1 and 2 will be permanently set to SPK and DECT respectively These settings are required for normal operation of the wireless system Turning OFF this feature will automatically set DO 1 and DO 2 to OFF again The Go NoGo comparison feature described in chapter 18 is turning the digital output lines 1 and 2 to the permanently setting as BUSY and GO respectively Turning OFF this feature will allow normal user setting of the DO 1 and DO 2 again 163 164 Appendix 1 Index If both the Nor1516 and the Go NoGo features are turned ON simultaneously the digital output settings of the Nor1516 will have priority AC out 3 5 mm stereo jack Both channels have identical sig nals driven by two separate amplifiers Load imped ance shall be 16 ohm or more Output voltage is gen erated by the 48 kHz DAC based on data from DSP Normally a replica of the normalised microphone sig nal Full scale on the display bargraph corresponds to 100 mV Output impedance Less than 10 ohm AC coupled 100 uF Gain accuracy 1 kHz 0 2 dB Frequency response re 1 kHz 0 5 dB for 20 Hz lt f lt 16 kHz USB interface USB type 2 0 USB socket B411 SD card The instrument may use SD card for storing of setup information sound recordings and measurement re sult Memory size Up to 2GB Data storage Measured data is stored in the internal memory of the sound level meter or on the SD card T
33. O socket may be set to go high when the instrument is busy taking a new measurement i e in Running or Ended Stopped and until the instrument is ready to take a new meas urement i e entering the Waiting for trigger mode again As an example you may select the following Pin 1 Low 0 Waiting for trigger to the next measurement Pin 1 High 1 Busy with an ongoing measurement Pin 2 Low 0 Status Go Pin 2 High 1 Status NoGo Norsonic Nor140 Instruction Manual 1 3 octave analysis with upper and lower reference spectra activated 87 88 Chapter 19 Noise generator Noise Generator General By installing program option 10 access to an internal signal generator is gained Two types of signals are available either white or pink noise The generator is available on pin 15 on the general I O socket Matching cables with BNC connectors for the noise output are available under part numbers No r4513A and Nor4514A The option 10 allows noise excitation to be used for measurement of reverberation time if the instrument is equipped with option 9 Reverberation and for meas urement of airborne sound insulation Option 11 Note that the contents in each menu will depend on the options installed V Note Use cable Nor4513A and Nor4514A AVE Cables Nor4513 and Nor4514 shall not be used since these cables will keep the terminal for external reset permanently
34. STORE Alternatively the instrument may be set up to store automatically after each measurement see the general instructional manual for Nor140 for information about the file structure A stored result may later be recalled Correcting for background and occupancy noise The STIPA method considers the effect of the actual background noise when the intelligibility is assessed However in some cases we want to find out what the intelligibility would have been if we had a certain back ground noise A typical application will be to assess When stored a file number is shown in the upper line is automatically assigned to the measurement STI 0 81 Excellent CIS 0 91 LA 69 3 NCorr STI 0 81 Excellent CIS 0 91 RIBRWG Edition of the background noise level STI 0 81 Excellent CIS 0 91 LA 69 3 ON STI 0 81 Excellent CIS 0 91 BIBRWG ENTER Noise edit A oct Lea 125Hz 45 0 250Hz 51 0 500Hz 52 0 1 0kHz 2 0kHz 35 0 4 0kHz 27 0 8 0kHz 25 0 BiRWG Norsonic Nor140 Instruction Manual the intelligibility in an auditorium with audience when the auditorium was measured without For such appli cations the optional noise correction may be used Measure the STl value as described above Place the cursor above the field Off in Noise correction Off and press INC or DEC button to toggle the value to On The results will be recalculated to accoun
35. a eee 137 Setthie SpeechileVel aen esto ete PENES dite Mies ate Dace Li tecti eed eft 137 Sele ctthe S TIedmode s a S ce ERI ede REIR ede E E e c TENER 137 Makirig aqmmeasuretmieli s aee e i ae ERE E RR RO Ee atts op Oa tpe HEN ERR 137 Store and recall thecresult s td ea 138 Correcting for background and occupancy noise eee 138 Real background NOISE esia ee Ed e bla e ed dt eec edet ee tO 140 Rrecision of the STIBAmethod uet t PET IE EDEN m 140 Analysis and interpretation of the results sssssssss em emen 141 lkirmitatioris orthe S TIPA metliod 5 rct ee e re ER ORO d e ED 141 Using Excel for further calc latioris osse Recette ae 141 SEC AG c Rr 141 Specifications sito erue m Ge TUR EE a ttem 142 xiii xiv Contents Chapter 25 Chapter 26 Chapter 27 FFT measurement mode INTOUCION e EE How to selectithe FFT mode ret eese cer anand ec tte ite due Makitigcatieaslremiell ostio noria Cali E MEE CONMECHIONS nai d ab n eM apii entire m Oud Storirgthe res lt n iced ae edes a La etm eda ARS Specification TOI ERT semet tet ee de o pru e D cL Dia cd tac ed Measuring vibration using the Nor140 Introduction PEE Accelerometer ad coe o D so de ddr ccm ICGP5type o ERRORI ND HO Rue n aM Glhiargedype us esse tunm o e tr men v ri LE Velocity and displacetent o com rc D ac eo a IC EY ial re aioe Pa M EE deos Technical specifications eeeeeee e
36. a exist additional microphone positions shall be used For the microphone array on the hemisphere an additional 4 point array is defined by rotating the original array through 180 about the z axis Note that the top point of the new array is coincident with the top point of the original array The number of microphone positions is increased from 4 to 7 Conditions b and c require more measurements in the region of high radiation Microphone Array on the Hemisphere Reference box 0 89r Measurement surface 10 1r 14 15 6 e 0 45r N Reference box 3 Key microphone positions o Additional microphone positions Key microphone positions are numbered 4 5 6 and 10 additional microphone positions are numbered 14 15 16 and 20 Measurement surface Norsonic Nor140 105 Instruction Manual One reflecting plane Two reflecting planes 7 d UL LA MMMM dd LA 9 d 4 NB Dimensions in metres NB Dimensions in metres Three reflecting planes 106 Chapter 22 Sound power Parallelepiped measurement surface The measurement distance d is the perpendicular distance between the reference box and the meas urement surface The preferred value of d is 1m and should be at least 0 15 m The value of d should be one of the following values in metres 0 15 0 25 0 5 1 2 4 or 8 Measurement distances larger than 1m may be selected for larg
37. analysis can be made successfully The measured functions are also available in tabu lated form as numerical values By pressing the TBL key before during or after a measurement you have instant access to the numerical version Another push on the key will restore the graphical display Statistics Adding option 4 to your Nor140 will expand your frequency analysis to even calculate the statistical level distribution for each frequency band measured In addition statistics will be calculated for the two spectral weighting networks employed A and C or Z weighting The class width is always 0 2 dB to ensure sufficient resolution and the results are presented in the form of eight percentiles with a resolution of 0 1dB Time profile measurements With Nor140 instruments equipped with the optional extension 6 you will be able to retain all the advan tages of the analogue level recorder principle while at the same time discarding all the trouble The optional extension 6 level vs time records the time profile of the A weighted equivalent level the A weighted maximum sound pressure level and the Z or C weighted peak level simultaneously The principle is based on dividing the measurement into periods of identical duration The period duration can be from 1 second and upwards in 1 second steps from 50ms in enhanced mode When a level vs time measurement is running the equivalent level will be calculated per period t
38. and more But you don t need to attend the measurement ses sions all the time In fact the Nor140 is able to do a lot on its own The measurement time can be preset to e g 30 minutes or an hour and the instrument put in a mode where it measures and stores the results then starts measuring again stores the results starts measuring again and so on Each measurement will be stored ina separate file but all files are stored in the same direc tory which has the name of today s date In this way the instrument will measure the periods you need And if this store and go feature which is standard is combined with the optional time profile each measurement will provide global data and a time profile with a resolution specified by you Of course the instrument will spend a little time storing the data housekeeping Therefore if you start the session with hourly measurements exactly on the hour long store and go sessions will after a while experience a small but significant time shift so that each period no longer starts exactly on the hour Enter synchro mode This feature standard in all models stops the measurement on the hour and re start the next measurement a couple of seconds later to provide time for storeage By sacrificing a little at the start of a measurement the synchronisation with the Norsonic Nor140 7 Instruction Manual time of day is retained a feature important to many of
39. band which may well be the case use the cursor keys to move the cur Sor in the usual manner You will note a horizontal line located 30 dB below the displayed top scale Remember that the displayed top scale is purely a display feature and not related to the measurement range setting This line represents the trigger level threshold for the impulse decay cap ture Use the INC or DEC key to change the trigger level threshold in 10 dB steps if applicable Press the START key The instruments start logging the level and waits for the trigger condition to be ful filled While waiting a W waiting is displayed Once the instrument detects a level above the threshold in the frequency band you have specified the capture of the impulse and its decay will begin An R will appear in the display when the measurement is running You should make the impulse excitation as soon as the W mark is displayed Once you have pressed the start key the trigger setting cannot be changed even if the measurement is not yet running To be able to change these settings you must terminate the ongoing measurement To terminate an ongoing Measurement you have to press STOP or PAUSE CONT In both cases the instrument will return to ready condition If a measurement has been made and the result table is displayed press EXIT to enter this condition The instrument will measure for 10 seconds and count down to O to indicate how much is left of the measu
40. below the display to navigate in the menu as usual and set the storage mode as re quired by INC or DEC e Select the appropriate place for storing the data either the internal memory or the optional SD card Other setup aspects The setup for a monitoring job will depend on the task so no absolutes can be given here However you should consider such things as e What information will you need and how detailed should it be e Measurement period length Profile resolution required if applicable The need for frequency analysis and bandwidth if applicable The functions to be measured The need for statistics if applicable The type of outdoor microphone unit for semi permanent or permanent installations Using windscreen The effect of using a gt windshield is discussed in Windscreen in the chapter Technical specifications e Adaptors needed if applicable Cabinet or casing required for the sound level meter Cables and cable lengths e External power to the instrument batteries or mains connection e Type of connection to remote PC modem GSM modem directly wired to the PC or maybe you will come by at regular intervals with your PC to down load acquired data The setup of Nor140 will be found in this manual while all accessories can be found in a separate leaflet or at www norsonic com Keyboard locked 00 02 00 061214 14 05 11 F SPL 30 c 64 9 A 33 6
41. by the CAL key is also selected in this menu The duration is variable within the 1 60 second range 0 09 500 A A Leq 90 0 Mk A 83 84 Chapter 18 Reference Spectrum Reference Spectrum General The Reference Spectra feature is used for compari son of any measured frequency spectrum with a pre selected user defined spectrum It functions both on 1 1 octave and 1 3 octave spectra The measured spectrum may be compared to an upper limit a lower limit or both an upper and a lower based on user defined boundary spectra If the meas ured spectrum exceeds the boundaries a NoGo warning may be given The Reference Spectra features will be available when option 2 is installed This option requires that option 1 1 1 octave filters is present Activating the Reference Spectrum features The Reference Spectrum features are controlled from the lower part of the Setup menu point 4 Freq Mode see figure The basic requirement is that the Freq Mode is turned On in the upper part of the menu In the lower part of the menu either the Upper or the Lower or both must be turned On These selec tion will turn on the currently stored upper and or lower Reference Spectra in the graphical level vs frequency display Frequency mode menu Freq mode Mode On Bandw 1 3 Ref spectra Upper On Lower Off Qc 1 Ref par EIBRWGS The upper and or lower spectra are displayed using
42. decibel or engineering units Corrections The correction for random response windscreen and preamplifier gain also applies in FFT mode of opera tion Number of periods in the average Compression factor i HA N 10 40 219 73 435 06 C 1 N 10 40 X 281 25 X 279 79 Y 78 5 Y 71 3 BiBRWG BiBRWG Level value Cursor frequency Hz Move the cursor to obtain the digital value for the spec trum at one particular frequency Use the field cursors amp and W to change the compression factor If the display is compressed more spectral lines are displayed as one line The cursor value will show the maximum value for all the lines represented by the cursor position In order to read the values for each spectral line you have to zoom until the compression factor is one C 1 Storing the result The measured spectrum may be stored in the instru ment and later retrieved or exported to a PC by using the NorXfer program The storing is as simple as in the normal mode of operation A file number is automati cally generated In the file list the file number is suc ceeded with the letter f indicating a FFT result The storing may be manual or automatic as in the normal mode of operation Norsonic Nor140 145 Instruction Manual Specification for FFT Sampling frequency FFT size Frequency lines Anti aliasing filter Frequency range Frequency resolution Window func
43. e Pans de de den ad ca cates tt cortar cd eid 11 Sele ctpreamplifier 25 caen ROB RERO Ree ARR 13 Settirig thie timexandidaltes s cie ne S PIER o rii trate 13 Calibrating the instrument eeeeeeeeeeeeeeeeeeee nennen enitn nnnm anna ninm annnm anna nnn 15 WENO calibre cari EE 15 No heed to adjustthetulliscale set cacon cierre rr e Gen RP a 15 Carryirig out the calibration incen Te de ADAE ep e E Foedus 15 Chapter 4 Chapter 5 Norsonic Nor140 Instruction Manual Simple sound measurements Setting the duration Statistics A dE E ahd in EA e E Ad a OR R A Instruments with time profile installed sssssseeee 21 setting the time CON Miri da A ac ee de 21 Instruments with multiple time constants onscreen danane ea i EN iSe 21 Multiple time constants and statistics 00 ee eee rere cnan crono ona rana air EErEE nE 21 C or Z as spectral weighting network 21 Making a mmeasretTiebiL 5 eor A ee he Eee etd tr EE ERE 22 Resutrimg an xerndedimeasuremleit ect crop rer de D ee eii tto 23 The back erase feature 3 cri em or iaa Ita 23 Displayinig the functions Measures 23 Displaying the resulttables rae ce e de 24 Statistics displaying the percentiles sssssssssssseee eene 25 Bisplaying the percentiles table coca ines 26 Storingsheacg lred dela c oot e eee do eee erase dee Loa es cono a et 26 Printing out the resul ss ia bene ope nre Anite he tee E iene eens 2
44. field and press PAUSE CONT for prolonging the measurement period When the measurement is ended press PAUSE CONT a second time The result will then have the required spatial weighting 1 3 2 3 The result may be further corrected to obtain the standardised and normalized sound pressure level Remote operation from a PC Remote operation of the Building Acoustics features is possible for the Nor140 in combination with the NorBuild CtriBuild software package Nor1028 Option 11 then requires all the options 1 3 9 and 10 to be installed in the Nor140 unit Option 11 in combination with the other required op tions includes all required remote commands for mak ing building acoustic level or reverberation time meas urements with the external CtrlBuild package Option 11 also extends the internal noise generator option 10 to include band pass filtered noise in addition to white and pink noise Further description of this option is given in the instructions for the CtrlBuild package Norsonic Nor140 Instruction Manual Swept Sine measurement technique Swept Sine measurement technique may be used for the measurement of the airborne sound insulation lev els or for the reverberation time in accordance with the methods described in the ISO 18233 standard The Nor140 instrument equipped with Option 12 Swept Sine measurements is able to perform this when controlled remotely from a PC in combination with the NorBuild Ctr
45. frequency band To see the global values 1 Make sure the instrument is in global mode a dis played in the upper left corner of the display If not press the A key to enter global mode 2 Use the fot key to go between the sound level meter display and the spectrum display Move the spectrum cursor as explained above The spectrum you see now is the global spectrum This spectrum should not be confused with the multispec trum feature The result tables The measured values can be presented tabulated as usual In multispectrum mode there are two tables available in profile mode e Each function shown for all frequency bands use the func key to go to another function e The functions measured shown for a single frequency band or spectral weighting network Norsonic Nor140 Instruction Manual These are shown in the Fig to the right as well as over leaf together with the displays and tables available for the global part of the measurement To produce the result tables in multispectrum mode 1 Press TBL once to produce Table 1 and again to pro duce Table 2 2 Press again to return to graphical display The key pressing sequence is also illustrated in the Fig overleaf while operating details are provided below Table 1 020419 0004S Use WA keys to move 0 2 7 500 up and down in table Ghee led dh keys to move to an 5 Ok Hz 22 l1 other moment in time and 5 3k Hz 19 9 FUNC to scroll throu
46. if option 10 Noise generator is in stalled Sometimes it will be convenient to have no ca ble between the instrument and the loudspeaker for the excitation This may be achieved by using a radio transmitter for the noise signal contact Norsonic for more information or to use a power amplifier with an internal noise generator such as the Nor280 Another alternative is to play a music CD with recorded noise Norsonic can supply a CD with the required excitation signal Nor1033 Norsonic Nor140 Instruction Manual The menu for airborne sound insulation is also used for facade measurements Airborne V EEEX r C S 5 6 mC L1 L2 T E Cal c result BiRWG Normally the loudspeaker is placed on the ground in a position which makes the angle between the nor mal to the facade and the sound incidence close to 45 The distance from the loudspeaker to the centre of the test specimen shall be at least 7m This may be obtained as shown on the adjacent figure if d is at least 5m Measurement of sound level The level may be measured in the normal mode of op eration and stored for later processing or the meas urement may be started from the calculation menu when the result is required for the calculation Then the measurement time has to be set up beforehand The source level shall be measured 2m in front of the facade outside at the centre of the fa ade ele ment This level is designated Li As stated in
47. in a folder with the name of today s date If this folder didn t exist it will be created by the instrument The first file gets the number 0001 the next gets the number 0002 etc If you choose to delete one of the files already stored you will leave a gap in the file list This gap will not be filled with a file stored later but be left open Otherwise you will easily loose track of which file contains what Files of selected folde Retrieving stored setups and data Folders Storing device Recall INT SETUP 0001M STNDRD 0002M 060823 060824 060825 MS 4 Recall INT SETUP STNDRD 060823 060824 Ms Recall INT STNDRD 060823 060824 060825 Ms 4 Recall INT 0002L STNDRD 060823 060824 060825 EWS 4 Once you ve pressed the RECALL key the display will show the selected storing de vice and a list of folders and the contents of one of them here this is the folder 060825 Use the INC or DEC to select the wanted storing device Use the vertical cursor keys to move up and down in the file list of this folder To be able to scroll in the folder list press the key once and then use the verti cal cursor keys to move to the required folder For example the folder con taining all the setups To display the files contained in the selected folder press the P key and locate the file in question by means of the vertical cursor keys Press EN
48. in today s folder S for stored 060824 0007S 120 This is setup No 4 stored in 00 00 05 this instrument S for stored 0 05 7 ES SETUP 0004S 120 Leq 80 00 00 05 z s 060824 pa a 12 9 15 36 28 7 A SSPL m 40 E WS A 44 0 C A 11 8 ws 0 General The set up parameters are stored separately for each mode of operation Due to this feature you don t have to readjust the filter bandwidth to 1 3 octave due to a previous measurement of STIPA which requires a full octave bandwidth The mode related set up covers most measurement parameters as selection of network measurement time time resolution frequency resolution etc How ever some parameters are global and adjustment in one mode will define these parameters also when the instrument is operated in a different mode Global parameters The following parameters are global and adjustment in one mode of operation for the instrument will be valid also in other modes of operation e Instrument sensitivity calibration e Preamplifier Polarisation voltage e Calendar clock settings Norsonic Nor140 Instruction Manual e Serial interface on off and baud rate or USB selection e Second weighting network C or Z weighting e Level range Normal High e Units dB or engineering units e Correction on off e Printer e Language for print e Instrument identification Option 11 Mode dependent parameters The parameters w
49. including being paused during a measurement nor when powered from an external source The automatic switch off feature may however be disabled if required for long term moni toring purposes Press SETUP gt 1 Instr gt 9 Misc par 9 AutoOff and use the INC and DEC to alter a setting from ENABLED to DISABLED f Pol volt Polarisation voltage The polarisation voltage setting menu opens up for the use of prepolarised microphone cartridges OFF MM A prepolarised microphone cartridge will nor s E mally exhibit reduced sensitivity when exposed AY to polarisation voltage It will regain its initial sen sitivity shortly after the polarisation voltage is no longer applied A conventional cartridge will appear dead until shortly after the polarisation voltage is switched ON and then it will work OK The above applies to all microphone cartridges supplied by Norsonic However a universal guarantee for all brands cannotbe guaranteed Norsonic is notliable for consequential damages following incorrect setting of polarisation voltage 11 12 Chapter 2 Taking a closer look a Navigating in the menus Observe the following general guidelines applicable to every Nor140 menu To navigate between editable parameter fields in the menu use the CURSOR keys The editable field currently selected is shown in verted white text on black background Use the INC and DEC keys to incre
50. input capacitance below 1 pF and will not modify the loading impedance The voltage representing the acceleration is transferred to the sound level meter through the preamplifier Typical attenuation through the adapter Nor1447 2 and the preamplifier Nor1209 is 0 1 dB Select the Standard preamplifier in the instrument set up menu but switch off the polarisation voltage Nor1209 Preamp Nor1447 2 Nor1466 Y Y Y d gt Microdot cable Normally supplied with accelrometer Accelerometer Example Assume the sensitivity for the accelerom By entering this value as sensitivity in the calibration eter is 2 5 mV ms 2 The level sensitivity is therefore menu the instrument is calibrated and the reading in engineering units will be given in ms Hemember to select ICP as preamplifier and set the preamplifier cor rection to Off 0 0025 2 d 52 0 dB 2 1 ms L 10lg Charge type If you use a charge sensitive accelerometer you need to know the capacitance of all cables and accessories in addition to the charge sensitivity and the capaci tance of the accelerometer The following example will show how to calculate the sensitivity The accelerometer is assumed to have the charge sensitivity 3 pC ms pC pico coulomb and a ca pacitance of 950 pF The capacitance of all cables and adaptors between the accelerometer and the preamp lifier is measured to be 230 pF The voltage sensitivity will be
51. level vs time with or without the spectrum as a function of time Consider setting the time constant If your instrument is not equipped with the optional ex tension 5 parallel time constants see Units equipped with multiple time constants you may want to specify the time constant to be used in the measurement Multispectrum is available as long as minimum option 1 and 6 are installed This is treated in chapter 9 Multispectrum measurements The time constant is used for the SPL the Lmax and the Lun measurements but neither Legnor Le make use of it To set the time constant press the TC key until the required time constant appears in the display To see this be sure to operate the FUNC key until any of the functions SPL the Lmax or the Lun appears in the dis play first Setting C or Z as spectral weighting network The Nor140 has three spectral weighting functions in addition to the filter bands These are A weighting and C or Z weighting The Z weighting is a replacement for the previous Flat or Linear spectral weighting func tions The Z spectral weighting circuitry is flat within at least 16 Hz to 16 kHz and is defined in the International standard IEC 61672 1 The Nor140 can make use of two of the three spec tral weighting functions simultaneously viz A weight ing and Z or C weighting To specify whether to use Z or C weighting e Press SETUP gt 1 instrument gt 5 2nd netw and navigate in t
52. logged profile may be transferred to a PC for further analysis Software like Nor1026 NorReview may be used for extensive analysis of the result Global vs profile The traditional sound level measurement and the fre quency analysis both consider the entire measurement as a whole without dividing it into smaller parts One may therefore consider these two measurements as global measurements while the level vs time meas urements represent the profile In the display the global measurements are denoted Y pronounced sigma while the profile measurements are denoted A pronounced delta To switch between the modes just press the ZA key Norsonic Nor140 Instruction Manual The Leg Lmax and Luin are measured for every pe riod separately and stored in a buffer All functions are A weighted apart from the peak level which can be set as C or Z weighted The enhanced profile ext 7 pro vides more options see Enhanced profile measure ments Profile measurements may be made in parallel with global frequency analysis filters are optional and in parallel with the traditional sound level measurement described in the chapter Simple sound measurements If your Nor140 is equipped with the multispectrum ex tension you may log the spectrum as a function of time See the chapter Multispectrum measurements for more on this The time profile is no less than an electronic level recorder 38 Chapter 6 Basic time profile m
53. measurement are stored with the date and the time of the day By pressing the ABS t key you may toggle between dis playing the absolute time when the data were acquired or the time relative to the start of measurement dura tion This is a display function the absolute time is always recorded for all measurements Setting up is easy to do After you ve defined the duration and the resolution all you need to do before you press the START key is to define the time constant and whether to use Z or C weighting as the secondary spectral weighting function During the measurement you have instant access to the global analysis and profile For each of these the function key lets you inspect all the functions meas ured For the global analysis the functions measured are the instantaneous SPL the maximum and the minimum SPL the equivalent level the sound exposure level and the maximum peak level All levels are measured as A weighted and Z or C weighted levels 5 6 Chapter 1 Introducing the Nor140 The time profile logs the A weighted equivalent lev el the A weighted maximum sound pressure level and the Z or C weighted peak level The enhanced profile option In need of even better resolution or better control of the functions meas ured No problem The time profile extension can be expanded into the enhanced profile extension our option 7 for the Nor140 Order it when you purchase your Nor140 or later if that s
54. nnoise ON LnA 19 9 1 Corr par LnC 19 9 LnZ 19 9 RWGS RWGS AR wWGS 159 160 Chapter 27 Technical Specifications Diffraction around the instrument casing The instrument casing is designed to have low effects on the sound measured at the microphone The figure below shows the measured effect of the instrument casing at reference environmental conditions Directional plot Microphone with extension cable 105 20 75 120 60 30 165 15 E 41809 ff 2 0193 y 165 15 150 KHz 49 230 105 75 105 99 75 120 x i i 60 150 165 41809 16587 N P 150 V pane i m d 1200 7 i iem 105 f 75 Directional plot horizontal tor vi 75 150 e a 165 3180 OL 9B 0 165 PA 150 300 120 i 60 105 75 Directional plot vertical Norsonic Nor140 161 User Guide Level dB 10 100 1k 10k 100k Frequency Hz Effect of the case reflection for sound approaching the microphone from the front The diagram shows the frequency response for an instrument with casing relative to the response for the microphone alone 2 1 co 2 T 0 gt o m 1 2 10
55. obtained by measuring the re verberation time or by recalling earlier measured val ues See the paragraph describing measurement of reverberation time If the optional noise generator is installed it may be used for the excitation otherwise impulse method has to be used To start a measure ment press START when the field cursor is in the field for reverberation time marked T When the required information has been entered the cursor will automatically be placed in the field for calculation of the final result If you are satisfied with the entered values press ENTER or if you want to make any correction move the field cursor to the re quired field and enter the corrected values or press DEL to clear averaged values When you move the field cursor to the field Results and press ENTER the following functions are calculated for each of the one third octave bands 50 Hz to 5000 Hz e The normalised level difference Dn e The standardised level difference Dar The apparent sound reduction index R e The source room level L e The receiver room level L e The level difference Dir e The reverberation time T M A Note that you have to be in the menu for z entering values before you are able to select Z another mode Norsonic Nor140 Instruction Manual Display of measurement result B 80 Results Criteria 1 3 oct R R 200Hz 27 6 C 2 0 250Hz 25 3 C so a150 2 0 315Hz 2
56. our customers The principle of optional extensions The capabilities and setup options of your Nor140 will depend on which of the available extensions it has been equipped with Extensions are modules made as software in the instrument or e g as software for your PC available for your Nor140 Norsonic extensions are always op tional and hence often referred to as options In this way you do not have to pay for features you re not go ing to use However you may find that your tasks are expand ing into new areas of acoustics as time goes by There fore a typical Norsonic extension will be available for installation as retrofit The optional extensions may enhance the operation of the instrument considerably Normally these types of options are called modes of operation Such exten sions may be transferring the instrument to an FFT analyser an analyser for speech transmission index or a building acoustic analyser for the measurement of sound insulation including measurement of the rever beration time Transducers Nor140 is normally equipped with microphone Nor1225 and preamplifier Nor1209 Other types of transducers may be connected to the input socket directly or by suitable interface and or power supply Pre polarised microphones may be used with the normal preamp lifier by switching the polarisation voltage off The in strument may supply current for ICPO type of trans ducers Adaptors from BNC to the input sock
57. preferably STI lt 0 2 the reading will have a high degree of reliability If the background noise can be switched off it is possible to measure the response to the STIPA exci tation and noise level separately The STl value may be corrected for the background noise later in the in strument or by applying the Excel sheet STIPA calc delivered with the instrument option This will eliminate the interference between a spiky noise signal and the STIPA method Precision of the STIPA method Because the test signal is band limited random or pseudo random noise repetition of measurement does not normally produce identical results even under conditions of steady interference The results centre on a mean with a certain standard deviation Typically the value of the standard deviation is about 0 02 with stationary noise interference With fluctuating noise for example a babble of voices higher stand ard deviations may be found possibly with a systemat ic error This can be checked by carrying out a meas urement in the absence of the excitation signal This should result in a residual STI value less than 0 20 An estimate of the standard deviation should be made by repeating measurements for at least a restricted set of conditions Analysis and interpretation of the results It is important to examine the modulation matrix to de termine the reliability of the results As a rule the modulation index in each octave band sho
58. re use of previous measurements When making several sound insulations tests where ei ther the source or receiving room is used in both tests it is Convenient to re use the averaged source level and or the averaged reverberation time from the first measurement By moving the cursor to either L L T or L before pressing the DEL key the corrected aver aged levels from the first measurement may be deleted by confirming the delete process Thereafter the new measurements for the second insulation test are repeat ed for the receiving room levels or reverberation times 125 126 Chapter 23 Building Acoustics Facade insulation General The facade insulation may be measured using the modes for airborne sound insulation the outdoor will then act as the source room See ISO10052 and ISO 140 5 as appropriate for further details regarding requirements for the noise generating equipment and the selection of microphone positions Use of traffic noise for facade measurement is not covered in this description as this requires simultane ous measurement in and outdoor However this can be achieved by using two Nor140 sound level meters or a dual channel system such as the Nor121 Please contact your local Norsonic office for further informa tion on such systems Terms and definitions The following terms are used in the display L2 sound pressure level 2 m in front of the facade dB The term is designated Li
59. shall be made to the cor responding figures Additional microphone positions Sound pressure level measurements are required at additional microphone positions on the parallelepiped measurement surface if a the range of sound pressure level values meas ured at the key microphone positions i e the difference in decibels between the highest and lowest sound pressure levels exceeds twice the number of key measurement points or b the source radiates noise with a high directiv ity or c the noise from a large source is radiated only from a small portion of the source e g the openings of an otherwise closed machine If condition a exist additional microphone positions shall be used For the microphone array on the paral lelepiped the numbers of microphones are increased as shown on the next page by increasing the number of equally sized rectangular partial areas If conditions b or e exists additional measurement positions on the measurement surface in the region of high noise radiation shall be used Details on this are given in the ISO 3746 Reducing the number of positions The number of microphones positions can be reduced if preliminary investigations for a particular family of machines show that by using the reduced number of microphone positions the determined surface sound pressure levels do not deviate more than 1dB from those determined from measurements over the com plete set of microphone positions in accord
60. show the spectrum or the classic sound level meter display will not affect the measure ment in any way Likewise going between the two display modes during a measurement has no effect on the measurement either 30 Chapter 5 Frequency analysis Switching to displaying the spectrum Having activated the frequency mode and left the menu just press the fort key to display the level vs frequency and press again to return to the other dis play Since no measurement has been made the only function producing frequency band bar graphs will be the SPL with the selected time constant If you press the FUNC key this will produce empty displays only If you did just keep pressing the FUNC key until the SPL reappears Switching between sound level meter display and spectrum display 00 05 30 010728 223924 214 L I SPL 90 x 8083 Z 83 0 BI WS Sound level meter Spectrum display display Making a frequency analysis To start a frequency analysis measurement e Set the measurement duration e Press the START key The R in the display indicates that a measurement is running The measurement is running and data acquired irrespective of whether the frequency spectrum is shown or not To temporarily halt an ongoing measurement e Press the PAUSE CONT key To resume a paused measurement e Press the PAUSE CONT key again Upon resuming the instrument will go on measuring until
61. since these keys are the lower most keys of the front panel and thus easy to reach during a meas urement None of these keys are used for other things during a measurement either Other markers inserted by the instrument As discussed in the side bar No back erase in profile mode in chapter 7 the single marker P is added to the periods to denote that these periods contain data acquired in pause mode In addition if you terminate an ongoing measurement prematurely by pressing the STOP key and later resume the measurement by pressing PAUSE CONT an S single marker will be added to the period within which the PAUSE CONT key was pressed i e we mark out the first period after resumption An R toggle marker will be added during record of the signal Option 8 If some of the specified tasks has been omitted due to work overload for the signal processor a W toggle maker will be added The total number of recorded signals and hence inserted R markers for one measurement is limited to 1000 In addition each measurement may contain up to a total of 1 000 markers of all the other kinds In these limitations each toggle marker only counts as one marker Instrument markers have priority The marker 4 is a toggle marker i e once activated it will assign a marker to every period occurring until it is deactivated again What happens if marker 4 has been activated while you press the STOP key or the PAUSE CONT key Will
62. stored You are prompted to accept the recalled or meas ured values as a part of the averaging process Press ENTER alternatively STORE to accept or EXIT alternatively DEL if you don t want to accept You may repeat the catching of data to obtain the averaged results from more measurements The number of measurements that has been accepted for the averaging is displayed by a number N Press the TBL key to display the averaged levels The averaged level L is obtained according to the following formula where L is the result from each of the N values N E 101g 4 aen dB k l The average level in the receiver room L2 and the average background noise level Lb are obtained in a similar way Entering values for the background noise level is optional If the level in the receiving room is more than 10 dB above the level of the background noise no corrections will be made and the final result will be in dependent of having measured a background level or not However if the difference between the averaged level in the receiving room and the background noise is between 6 dB and 10 dB a corrected level for the receiving room L will be used in the calculation as described in ISO 140 4 Ly 101g 102 10 qp The correction is limited to maximum 1 3 dB corre sponding to a measured level in the receiving room 6 dB above the background level The acoustic losses of the receiving room used in the calculation may be
63. the standard the spatial average of the sound level in the receiving room is required See measurement of airborne sound insulation between rooms for further information 127 Chapter 23 Building Acoustics Estimating the correction for the acoustic absorption Estimate k Room type Furnished Kitchen Bathroom Unfurni sh BiBRWG Measurement of reverberation time See measurement of airborne sound insulation be tween rooms for further information Calculating the result See measurement of airborne sound insulation be tween rooms for further information about calculating the results Service equipment sound pressure levels Survey method See IS010052 as this specifies how to measure serv ice equipment sound pressure level Option 11 has no special facility for this measurement However the service equipment sound pressure level may be meas ured in the normal mode of operation and the values specified in the standard may be calculated The standard specifies how the sound level in a cor ner position and in the reverberant field is averaged The first level shall be weighted with 1 3 and the sec ond level with 2 3 For equivalent levels L reg and Leeg this may be achieved by selecting a measurement duration corresponding to the required measurement time for the corner position Make the measurement by pressing START Thereafter move the sound level meter to the position in the reverberant
64. tions Press SETUP gt 1 Instr gt 6 Correct to gain access to the Corrections menu Navigate in the menu as usual and activate the correction parameter Wind scr by means of the INC and DEC keys Do the similar operation to deactivate When the windscreen correction is applied a W is displayed in the lower line of the display Random incidence and diffuse sound fields The instrument is normally equipped with a microphone with flat free field response and satisfies the class 1 requirements in IEC 61672 1 to free field response By selecting the random response correction network in cluded the instrument will satisfy the class 1 require ments in IEC 61672 1 to random response as well as ANSI 1 4 1997 Type 1 Not included in the versions for the German speaking markets The nominal cor rection for the random incidence correction network is shown in section for specifications Press SETUP gt 1 Instr gt 6 Correct to gain ac cess to the Corrections menu Navigate in the menu as usual and activate the correction parameter Random by means of the INC and DEC keys Do the similar op eration to deactivate When the random incidence cor rection is applied a R is displayed in the lower line of the display Measurement of low sound levels When measuring very low levels the indicated level may be influenced by the self noise of the instrument If you measure an A weighted level of 25 dB which is about 1
65. to measurements terminated by themselves only If you terminate a measurement by pressing stop the instrument will not restart Note that some time will be spent on storing the acquired data Therefore a slight delay typically 3 4 seconds in the restart moment will be observed e Synchro which compensates for the time spent on housekeeping i e storage of data etc to maintain synchronisation with the time of day This works in the way that the instrument synchronises itself with the next full hour of the time of day To be active synchro requires a minimum measurement time duration of 30 seconds per individual measure ment Synchro an example Assume that you set up the instrument to measure in periods of one hour and that you start the measurement at 08 52 40 The first period will last 7 minutes and 20 seconds ending at 09 00 00 To give room for storage Going to measure very high levels As an optional extension the Nor140 is able to measure very high sound pressure levels with out changing the microphone cartridge see High levels in the Technical specifications for details Norsonic Nor140 Instruction Manual the succeeding period will then be truncated and start a couple of seconds after 09 00 00 Each next measure ment will then be a little less than an hour long to enable ending again at 10 00 00 11 00 00 etc A similar situation when the measurement period is set to 15 minutes will be The first period
66. to a measurement Norsonic Nor140 Instruction Manual 53 54 Chapter 10 Engineering Units Engineering units Introduction The Engineering Units feature allows you to recal culate and display the result in physical units e g the sound pressure may be indicated in Pascal instead of decibel In conjunction with other sensors than the usual microphone the general EU sign may indicate any relevant physical quantity All values are still stored as level values This al lows even stored results to be displayed as dB or EU dependent on the selected setup when the results are retrieved and displayed The selected format for units either dB or EU is indicated in the lower left corner of the screen as shown on Fig below When values are transferred to a PC the dB format will be used independent of the setting in the instrument 01 00 00 7 Engineen unis is indicated by an EU sign in the lower left 0 149 1 corner of the display FSPL 804 48 2m A 5 29m puRwes Selecting Engineering Units The selection between levels in decibel or linear units in EU is selected in the instrument set up menu Press SETUP and select 1 Instr 9 Misc par 6 Units Use the field cursor to highlight dB or EU as appropriate and press ENTER repeatedly until you are back in the ordinary display How values are indicated Due to the high dynamic measurement range for Nor140 the measured valu
67. to your PC In 21 System Restore Automatic Updates Remote po ss Ez General e Hardware Advanced Name Comments Accessibility Options Adjust your comput SE Add Hardware Installs and troubl X Add or Remove Programs Install or remove pr Agr Administrative Tools Configure administr in Autodesk Plot Style Manager Adds removes and Autodesk Plotter Manager Adds removes and A Automatic Updates Set up Windows to 9 Date and Time Set the date time Sh Display Change the appear Folder Options Customize the displ fronts Add change and T Game Controllers Add remove and c WP internet Options Configure your Inte akeyboard Customize your sy Mail Microsoft Qyfook P Mouse Custopj your mo B Network Connections Coyfffscts to other c Network Setup Wizard unch the Network e Phone and Modem Optons Configure your tele as Power Options Configure energy s printers and Faxes Shows installed prin Regional and Language Options Customize settings Dy Scanners and Cameras Add remove and c scheduled Tasks Schedule computer security Center View your current s 9 sounds and Augbevices Change the sound s dl Speech Change settings for system See information abo dh Taskbar and Start Mens Customize the Start 8 User Accounts Change user accou Windows Firewall Configure the Wind a Wireless Network S
68. together Jack plug for signal out Ground Signal 2 Signal 1 Use a stereo plug Never use a mono plug for the signal output jack as this will short circuit one of the out puts Although it will not destroy the instru ment the poser consumption will increase Trigger General Noise monitoring often requires operating a sound level meter out in the field for unattended long term measurements The trigger option option 16 allows the measurement to start when a selected condition is satisfied The condition may be e A certain time of the day e An externally supplied trigger signal is activated Level is above a specified threshold By using the clock trigger a measurement may be started at a specified time of the night even if the instru ment is set up during daytime The result may be stored automatically the instrument can be picked up later and the results downloaded By setting the storing option to Repeat a meas urement may be started automatically each day at the same time Ensure that the measurement time is se lected so the measurement is terminated before a new trigger condition is satisfied The measurement may also be initialised by a trig Triggering a sound record The triggering of sound records are covered in the section Recording the sound Norsonic Nor140 77 Instruction Manual ger signal from an external device When started the measurement will last as long as se
69. which appears in the display as 1 4 is entered to later serve as an identification of the type of noise This can also be referred to as adding a marker to the measurement For example in a traffic noise measurement a bus passing may be identified by the digit 1 while trucks may be identified by 2 unexpected vehicles by 3 etc In the profile display the markers appear as dots or lines below the graph If you move the time cursor onto such a dot the marker type i e its number will appear in the display During ameasurement adding any of the markers 1 2 and 3 will assign the corresponding marker number to the current period only Adding marker number 4 however will assign this marker to the current period plus all consecutive periods until the marker again is deactivated A typical application for marker 4 is to de note intervals of particular interest Recording the sound The instrument may be set up to record the sound dur ing a measurement facilitating easy identification of a noise source The start of the recording may be trigged by the noise event an external command or started by pressing the RECORD button Different formats for the recording may be select ed to balance the requirements to signal quality and memory usage Excellent for noise monitoring With the Nor140 you are able to do nearly all types of noise measurements community noise industrial hy giene product control noise mapping
70. within this menu Use the NETW key to switch and the lower limit for time resolution there is no differ between filters A and C or Zweighted which is ence between basic and enhanced time profile mode set up in the 2nd network menu see Simple sound measurements for more on this Selecting which functions to log We always recommend that you keep the number of functions to measure as small as possible This helps to maintain the overview and keeps the amount of Functions to log setup menu memory spent low Although it may be tempting to measure everything do not forget that you are go L t par L t par ing to review the acquired data afterwards How much A SPL time are you willing to devote to that A Leq 1 0 A Leq 1 A Max 111 A Max 1 Setting up the functions to log A Min 000 A Min 0 A LE O 0 A LE 0 1 To gain access to the profile function activation A Peak O A Peak 0 menu press SETUP gt 3 L t par This menu looks as shown to the right 2 Navigate in the menu as usual and use the INC and Setup menu with multiple time constant option left and DEC keys to activate the functions required for your without the multiple time constant option right Units with multiple time constants installed may in clude the time constant setting in the setup see the Fig below left Functions like Leg Lmax Lu and Legak are measured during each period The SPL however is sampled at th
71. 0 dB above the typical self noise of 15 dB the contribution from the self noise will make the reading to be 25 4 dB or 0 4 dB too high Option 18 allows the A weighted and C weighted Z weighted levels to be corrected before they are displayed The correction is done by subtraction of the energy related to the self noise The figure below shows the linearity error as a function of the difference between the true sound level and the self noise level The upper part shows the error without compensation and the lower shows the error with ideal compensation and for Norsonic Nor140 Instruction Manual a compensation where the estimated self noise is 1 dB and 1 dB from the real self noise level The correction is based on the following equation where Lm is the measured level signal plus self noise Lnoise is the self noise level and Lc is the corrected level shown on the display Press SETUP gt 1 Instr gt 6 Correct to gain ac cess to the Corrections menu Move the field cursor to S noise self noise and toggle the value to ON by using the INC or DEC keys Press 1 for correction parameters Enter the values in dB for the self noise for the different weightings A C and Z Use the arrow keys to move the field cursor between the fields Press ENTER after entering a numeric value and for leaving the menu When the self noise correction is active a S is dis played in the lower line of the display Measu
72. 119 120 Chapter 23 Building Acoustics Display of measurement result Results Criteria 1 3 oct R R 200Hz 26 8 C 1 0 250Hz 27 6 Cso 3150 1 0 315Hz 29 2 Cso s000 0 0 400Hz 36 5 C100 5000 0 0 63082 32 9 Cer 0 0 800Hz 28 0 Cer so 3150 7 0 1 0kHz 25 2 Cer so so00 7 0 1 25kHz 27 3 Cer 100 5000 0 0 Watd 28 0 Watd 28 0 Calculating the Airborne sound insulation according to the Engineering method After selecting the Building acoustic mode select 3 Airborne Enter the value for the room volume V and press ENTER or move the field cursor to C and press ENTER for a calculator The calculator allows you to enter the length width and height of the room in metres in order to calculate the volume After the volume is en tered the field cursor automatically moves to the next parameters to be entered Area S Enter the value or use the calculator The field cursor automatically moves between the ields as values are entered If you want to adjust any previously entered value use the arrow keys to move the field cursor to the required parameter The next set of values to be entered is the sound levels in the source room L1 for each one third octave Recall a measurement by using the RECALL key or f Note that you have to be in the menu for AVE entering values before you are able to select Y another mode press START for starting a measurement Measured values are automatically
73. 2m in ISO 10052 and ISO 140 5 average sound pressure level in the receiving room dB reverberation time in the receiving room s Note that you have to be in the menu for enter ing values before you are able to select another mode To Dor Dn V Ao reference reverberation time equal to 0 5 s reverberation index dB standardised facade level difference dB The term is designated Damnr in ISO 10052 and ISO 140 5 normalised facade level difference dB The term is designated Damn in ISO 10052 and ISO 140 5 volume of the receiving room m reference absorption area equal to 10 m The relations between the quantities are given by the following equations Sound excitation for facade measurement T k 10 lg AT 0 Dir L L k D L L k 10 lg es The values are calculated for each octave band For Dw and D a single number value is also calculated The value corresponds to the 500 Hz value for the ref erence curve after shifted it in accordance with the method specified in ISO 717 1 for octave band levels The reference curve is shifted in one dB steps until the unfavourable deviations between the octave band re sults and the reference curve is as large as possible but not more than 10 dB for octave bands or 32 dB for one third octave bands Noise excitation The applied method requires broadband noise to be used for the excitation The noise may be generated by the instrument
74. 3 4 L99 0 43 1 WS 4 ocooo o da ll iie up 00u 0uocooneo ooo The user defined setting applies to both spectral weighting settings The two cannot have individual settings Displaying the percentiles table To produce the percentiles table press TBL to enter the result table and TBL again to enter the percentiles table Units not equipped with the statistical exten sion will exit the table upon the second push on TBL and return to the sound level meter display mode The sequence is shown in the side bar Storing the acquired data The Nor140 has a large non volatile memory to hold the measurements The memory structure resembles the memory structure of a personal computer in the sense that both use folders and files In addition data may be stored on a detachable SD card The structure for storing data is very simple The folder has the name of today s date and the files are numbered consecutively from 0001 and upwards Con sequently the maximum number of measurements per day is 9999 but this should be a limitation most people will be able to live with After all you are going to look through these files later as well aren t you Storing the acquired data e Press the STORE RECORD key The display will show the folder and file number All aspects of the memory handling are discussed in detail in Memory handling Printing out the results By connecting a printer to the
75. 5 8 Cso soo0 9 0 400Hz 35 7 C 100 5000 9 0 630H2 Cer 2 0 a B00 Hz 37 9 Cer so 3150 73 0 Ru 36 0 1 0k Hz 41 0 Cor so so00 5 0 XR 37 2 1 25k Hz 43 0 Cer 100 5000 5 0 500 Hz Watd 36 0 Watd 36 0 Note that Ls is now the level in the receiving room cor rected for the background noise and thus may deviate from the entered averaged value For the values D Dn and R a frequency weighted value according to ISO 717 1 is also calculated together the spectrum adaption terms Coo 3150 marked as C Cso 3150 Cso 5000 Cro0 s000 Cir 100 3150 Marked as Cr Cu 50 3150 Cir 50 5000 and Cr 100 5000 Pressing the FUNC key repeatedly will display the different functions The weighted values are all rounded to the nearest dB If you want to go back to the calculation menu just press ENTER Press the MODE button if you want to return to nor mal mode of operation Store and recall You may store the result by pressing STORE The file is automatically designated with the next free file number suffixed with the letter B indicating building acoustics 122 Chapter 23 Building Acoustics Averaging levels or level differences When you measure the levels as described and make the average of the results the levels in the source room are averaged to obtain the mean value for the source room The averaged level for the receiving room is ob tained in a similar way The level difference is calculat ed as the difference of the
76. 6 Frequency analysis Setting CUA OMY ak tereti a imei uu ed la dla dee ele ata cas tek tee ird cdd Statisties a shy e e RR diede i ut A ted E RENE Instruments with time profileinstalled ei tr Ier i eunt Het etes 28 Consider setting the time constant ssscscsensenin aa nne enne 28 Setting C or Z as spectral weighting network eee 28 Activating the frequency Mode i ie ec esce rte eU deter OR E rade dre e XN pet ente trt eR Bs 29 Switchirig to displaying the spectru s cete ree oU Ner bet Um 30 Making a frequency analysis e esee den D RC DUI GRE DURS ibas 30 R surming aniendedimeasureriefiL iier te E DEDERE a B MIR Rege nc e E reed 31 The back erase feature a a e eoe de e epo Pere e e ud ee dre aet ee ea es 31 If you ve measured for less than ten seconas ssssssssssssses een 31 Displaying the furictions measured n ete e nat em deat e eo ine D c RPG Oe pert 32 No SPL after the measurement e ececececeee ec eceeeeeeeeeeseecesceeeeceeseeeceecseseeeeseeseesetsseteeesteeetseeeseetesees 32 Displayihng the result tabl s s e do oben Ane he dea ae eee 32 Statistics displaying the percentiles ssssssssssssseemeeeeees 35 storing the acquired data os eee rem ede dat eO pO nes 36 Printing outthe results otim e eO dpi ro mutet dde bts quedes 36 vii viii Contents Chapter 6 Chapter 7 Chapter 8 Chapter 9 Chapter 10 Chapter 11 Basic time profile measurements
77. C can be by the serial interface or by USB 70 Chapter 14 Transfer of data to a PC Select USB or serial The selection between serial RS232 connection and USB is done by pressing SETUP gt 1 gt 2 Select the wanted interface by INC or DEC If serial interface RS232 is selected select the appropriate baud rate To transfer measured data from the Nor140 to a PC by serial interface you will need a Nor1441 cable available separately contact your local representative or the factory To transfer measured data via a modem you will need a Nor1489A cable for GSM modems and Nor1490 for conventional modems Both cables are available separately For the use of USB you need a standard USB ca ble Nor4525 included and a suitable USB driver as found on the application CD accompanying the sound level meter A recommended way to transfer data to a PC is by means of the software program NorXfer Nor1020 The programs NorXfer and NorVirtual Instrument are included on the CD accompanying the sound level meter We propose that you first install NorXfer and later the NorVirtual Instrument When you select to use USB the PC will look for the proper driver to be in stalled for use by both programs Password The password feature may be turned on for provid ing extra safety in some applications against un wanted communication to the instrument lf this feature is switched on all communication to the instrument on the serial and USB
78. Display of measurement result Results Criteria 1 3 oct L h 200Hz 44 1 Cr 14 0 250Hz 43 0 r so zsoo 14 0 315Hz 42 6 400Hz 46 6 630Hz 52 8 800Hz 62 1 1 0kHz 60 0 1 25kHz 59 3 Watd 69 0 Watd 69 0 Ris Ris The averaged level L is obtained according to the following formula where L is the result from each of the N measurements N L tog ron dB k 1 The average background noise level Lp is obtained in a similar way Entering vales for the background noise level is op tional If the level in the receiving room is more than 10 dB above the level of the background noise no correc tions will be made and the final result will be independ ent of having a background level or not However if the difference between the averaged level in the receiving room and the background noise is between 6 dB and 10 dB a corrected level for the receiving room L c will be used in the calculation as described in ISO 140 7 Lye 101g 10 10 qp The correction is limited to maximum 1 3 dB corre sponding to a measured level in the receiving room 6 dB above the background level The acoustic losses of the receiving room used in the calculation may be obtained by measuring the reverberation time or by recalling earlier measured values See the paragraph describing measurement of reverberation time If the optional noise generator is installed it may be used for the excitation otherwise impulse method has to b
79. EC61672 1 2002 5 Electroacoustics Sound level meters Part 1 Spesifications The options included in the basic instrument may vary Please check with your local supplier for the lat est information Type of instrument Sound level meter IEC61672 1 class 1 group X measuring exponential time weighted levels integrat ing averaging levels and sound exposure levels If 1 1 octave band or 1 3 octave band filters are installed the instrument complies with IEC 61260 class 1 The instrument also complies with the previous standards IEC 60651 type 1 and IEC 60804 type 1 Norsonic Nor140 User Guide The instrument conforms to a number of national standards such as DIN 45677 1997 ANSI S1 4 1983 ANSI S1 4A 1985 Type 1 and ANSI S1 43 1997 Type 1 Bandpass filters conform to ANSI 1 11 2004 class 1 Analogue inputs Number of channels 1 Input connector 7 pin LEMO connector for Norsonic microphone systems LEMO ECG 1B 307 CLL Preamplifier Nor1209 Normal or ICPO type by menu selection Preamplifier Nor1209 Preamplifier supply voltage 15 volt max 3 mA Polarisation voltage O V and 200 V selectable Maximum input signal 11V peak Input impedance More than 100kohm less than 650pF Preamplifier ICPG Supply current 4mA Supply voltage 24V Input impedance More than 100kohm less than 650pF 152 Chapter 27 Technical Specifications Measurement range 0 3 uV to 7 V RMS in one range correspondin
80. Engineering units eeeeeeeeseeeeeeeeeee eene n nnn nnn nnn nnn sait nnns sinn aate atna ansia 54 Introducir EET 54 Selecting Engis UIS utt iim ata ena dl er tetas 54 How values are indicated iii e Eo cae Aah VR euet 54 Relation betweeridB and EU cris cesses re it be ROI adie coe Nor e ER theese 55 Calibration eene eem qae epe eui ad m iaa 55 Memory handling eeeeeeeeee esee eene rr 57 Memory Structure 57 Internal Memory SIZE A UENIRE Ne us 57 SDcard meros cederet reee oro decanos pecas muevo encata sate do ro ors e de ld 58 Norsonic Nor140 ix Instruction Manual FOtIDnal nc A a 58 Selectithe device lee EN EET 58 Storinig a measurement setup noa cene ca Tec e ue doa Db eec e e pact it e d deas 58 EIE AE 59 Globalparameters eed ope editt M Rte tr 59 Mode dependent parameters sustantiva isis 59 StOring AMES Mii a Add seed ce eq RAT EATUR eI AE 60 hetrievinig stoered setups ahd dal tite ERI o ORE PORRO ed EDO ere 62 Standard Setups acte ae baci ide RE ode oh SERRA 62 Clearing files and folders in the memory cceccecceseeecceeeeeeeceeeaeecaeeaeeeeeeaeeeeesaeeeesetaeetsetaneseeateess 62 Clearing a single flle ere ac eR ADU EO Ee pase t seid de 63 Clearing folders or the entire memory meer 63 Chapter 12 Automatic storing of data and noise monitoring eene 64 Automated storage of measured data sse neret nnns 64 Aval
81. FFT Note that the instruction manual describes a fully equipped instrument Your version may not have all the optional extensions available Extensions may however be installed as retrofit any time Detailed technical specifications are found in the last regular paragraph Our objective with this manual has been to address your goals and needs Please let us know how well we succeeded vi Contents Contents Chapter 1 Chapter 2 Chapter 3 Introducing the Nor140 sound level meter No external Module ias THE TUNCHONS Va DH o t e een ut c HUIUS 2 he mainfeatures am OverVI8W s eiat rei recte ee ee et wind EE EU E Eae 2 Realtime freg ency analysls s intent wating Oe ER HR ON ee ates GAUGE niinc t E Rennen 4 Time profile meas uremerntts ce einen rei p e d ee EP Rer 5 Multispectral Measurement e ri Een eR e E Eee tb Ere uter tas da 6 SUCE COAN sc tet denm eee od RE ede te ER bo RT et 6 Recording the SOUL senec i tecti OO RE RP OR drei RU e RUP HE DO edt 6 Excellentfor noise Montong cia ee doe eA ea eC eae ee 7 THE Principle OF OPtIOMAlSXtEMSIONS cer ico 7 HAMS OU C CRS ees oye oat sce wes tte e ei ebd dp tt obe bd A AA teas 7 Check which extensions are installed enne 8 Workload iii EE 8 Taking a closer look at the instrument z Switehing ON OFF x ti tae M Rd Onithe use of batteries eiecti ce e dpa eam aca ad ese Pede POW Moltage Situatoris ome euro deed visi sue seee dos dinner da cd
82. For reflecting planes with higher sound absorption coefficient e g grass or snow covered ground the measurement distance shall not exceed 1 m For indoor measurements wood en and tile floors are also permitted No reflecting parts that are not part of the source under test shall be located within the measurement surface The K factor The environmental correction factor K accounts for the influence of undesired sound reflections from room boundaries and or reflecting object near the source under test The magnitude of this factor depends principally on the ratio of the sound absorption area A of the test room to the area S of the measurement surface The magnitude does not depend strongly on the location of the source in the test room In the ISO 3746 the environmental correction factor K is given by K 10lg 1 4 S A dB where A is the equivalent sound absorption area in the room at 1 KHz in m S isthe measurement surface area in m Environmental corrections as a function of A S are illustrated on the previous page Approximate method The mean sound absorption coefficient a of the sur face of the room may be estimated using the table shown on the next page The value A is given in m by the formula A aS v in which a is the mean sound absorption coefficient given for A weighted quantities in the table a few pages ahead S is the total area of the boundary surfaces of the test room
83. IBuild software package Nor1028 Option 12 requires all the options 1 3 9 10 and 11 to be in stalled in the Nor140 unit Swept Sine measurement of sound level Upon connecting the Nor140 to the PC running the NorBuild software package with the CtrlBuild remote feature the selection of Swept Sine technique is made in the Measurement Mode menu of the software Click on the point for Level Swept Sine Measurement mode Level Normal Level Impact Level impact lArbore Level Background Level SWEPT SINE Reverber anon Normal Reverberaton SWEPT SINE Nest Carcel 129 Chapter 23 Building Acoustics The different choices for the actual Swept Sine level measurement are then displayed in the Measurement Setup menu Frequency range Lowel bequency Upper heguency zw he Sweep duration pem None kvel Ber 6 148 amp Number ol pesvaenerts Nowe type Sel deli Bock New gt teen Cancel In the Measurement menu there are two settings that differ from the normal operation of the NorBuild software package Sweep duration is used for selecting the speed of the sinus sweep used in the measurement This can be set to Short Medium or Long which makes the duration lasting approx 1 5 or 11 minutes respectively The longer duration the better S N ratio is achieved Required S N ratio is setting the acceptance ratio for the measured results Should any frequency b
84. If you ve measured for less than ten seconds If the measurement has been running for less than 10 seconds when you press the PAUSE CONT key the entire measurement will be erased upon resuming the measurement If less than 10 seconds have elapsed since the last time you resumed a paused measurement only the part of the measurement acquired since the last resume will be erased Data acquired earlier are assumed to be accepted The measurement time elapsed counter will be up dated to reflect the back erase Note that the statistics buffers optional extension will be updated similarly 31 32 Chapter 5 Frequency analysis Displaying the functions measured The instrument measures the A weighted and C or Z weighted SPL Lmax Luin Lodi Le and the Lreak Note that the SPL Lmax and Lun are all measured with the selected time constant while the rest do not make use of the time constant at all The same functions are available in the frequency analysis with the exception of Lpeax The peak level is not measured per frequency band In addition Tuaxs is not available for frequency analysis applies to units equipped with the optional extension 0 However since the frequency analysis is made in parallel with the traditional A and C or Z weighted sound level measurement the broadband peak levels and the Tmaxs levels are still assessed during the Measurement v 4 What can be done to the measured data Data acquired a
85. Or n ren etae at eps 103 Hemispherical measurement surface ssssssssssssseeeneee menm 103 Hemispherical microphone positions sssseem meme mener 104 Additional Microphome POSitionS ce crt te e pente eie ce erp eee 104 Parallelepiped measurement SUFTaG6 ern Et rt OR OE t EH HE OF e HERR 106 Microphone pOSIIOTS odo tae o Ee HEX DD Ta aie DO eii 106 Additionalimicrophonmne zpOSItlOrls s n REPE a ha rust ners retis 106 Reducing the number of positions nh e eere eee qe bg 107 Mic positions one reflectirig plane ier e adie oer nen ib i OR Rer 107 More than one reflectirig plane eed eed a teu deed 107 Sound power acoustic environment requirements 109 Specitic requiremients i cte edet eed ARI ee A A a 110 PP 110 Approximate Method 0 rre t ta oe a RD ID a opc ec nde 110 Using reverberatlor time sia trar 110 xii Contents Chapter 23 Test room qualificationr requirements rne e n eed e pedes 111 Measuring the Sound POWEL s eae earn EO RR PRO OE RUM ER OE baee HE ERR 111 Making Measurement o ir ee a i eroe n ta em a e enim 111 BaCKGlOUNGINOISE cusco latas 114 Measurement Surface ni cA OP ed Ane aed dedu ied 114 SOUMA POWER teslis s eie tte ioter alte O 114 Building Acoustics cccsesenesseeeeeseeeeseneeeneeeeeeneneeeseeeeaseeeeeaseeeesseeesaseeeseaseneenseneeesenenes Introdctlon ott e t at eue iod ect e bedeuten d ede ceti tee tbt Terms and defi
86. Press SETUP gt 8 and menu for specifying the record ing will be shown Select the duration for each recording in seconds Enter a value in the range 0 to 9999 seconds by keying in the value or by using INC or DEC to modify the displayed value The value O is used for selecting a recording which lasts to the end of the measurement Select the required format for the recording by se lecting the number of bits and appropriate sampling frequency All recordings are made in a standardised WAV format which allows most media players to play the recorded file Record setup menu Record trigger setup Record Rec trig Duration External ES s Gain Level 48 dB ON Format Delay 16 bit 2 58 E 1 Trig par 81 82 Chapter 17 Sound recording Setup how to start a recording A press on STORE RECORD will start a recording with the selected duration If the trigger option is installed Option 16 trigger ing from an external signal or from a noise event is also viable Press SETUP gt 6 for triggering and then select 2 for record triggering You have to select between the following alternatives Manual trigger Set the external and level triggering to OFF Select the time delay between the trigger command and the execution A value in the range 5 to 99 may be used 5 means that the record starts 5 seconds before RECORD was pressed Note that a measurement has to be running before you are allowed to store a record
87. RS232 interface the results can be output to a printer This is treated in de tail in Making hardcopies Frequency analysis As an optional extension 1 you may have your Nor140 equipped with parallel octave band filters By adding the optional extension 3 third octave band filters become available as well The frequency range expressed as centre frequencies is either 8 16 000 Hz or 0 5 16 000 Hz for the octave band filters and 6 3 20 000 Hz or 0 4 20 000 Hz for the third octave band filters When you make a frequency analysis this comes in addition to the traditional sound level measurement as described in the chapter Simple sound measure ments Setting the duration Your instrument may or may not be equipped with the optional extension 6 which is the time profile log ging This affects the look of the Measurement duration setup menu To read more about optional extensions see The principle of the optional extensions How the menu looks with and without the optional extension 6 installed is shown below To produce the measurement duration setup menu e Press SETUP gt 2 To leave the menu press the ENTER key Norsonic Nor140 Instruction Manual Instrument without the multispectrum extension option 8 are not able to capture the spectrum as a function of time However instruments equipped with the time profile extension the basic version as well as the en hanced version may log the A and C or Z weight
88. TE If the Mic Check feature is used during a running measurement the measurement will be influenced by the inserted voltage signal Hence this part of the measurement should be excluded from the results in the post processing of the measurement data in order to give the correct level on any measured sound source Please note that the Mic Chech feature requires the use of the Norsonic Preamplifier Nor1209 All types of measurement microphones can be used both polarised and prepolarised The Mic Check level is dependant on the microphones car tridge capacitance Hence a Y microphone will return a much lover signal level than 90dB The Mic Check feature works also with the Norsonic Dehumidifier Nor1284 mounted Norsonic Nor140 19 Instruction Manual Simple sound measurements The Nor140 may still be used as a simple sound level meter The only thing you really need to set up is the V Z Navigating in the menus Observe the fol measurement duration which at least must be set up AY lowing general guidelines applicable to every to match the amount of time you intend to be measur v Nor140 menu ing If it is set to a longer time this will constitute no a To navigate between editable parameter fields in problem just press the STOP key when you want to the menu use the cursor keys terminate an ongoing measurement However you should consider the settings of the The editable field currently selected is shown in time cons
89. TER to recall the ocated file setup or EXIT to eave the menu without recall ing any file setup Norsonic Nor140 Instruction Manual Standard set up Measurem Time Ref Aleq AFmax Cpeak fort vot of ema m tw m me fe uro i I9 Normal th ts Man auto fc 1rot ALe AFmax Cpeak 1 1 octLeg Off Normal th ts Man auto fc 13 oct Alea AFmax Cpeak 1 3 0ctLeq off _ repo pr feee auto foo roer toto pre pp gt feee fawo fo wep fo prev ppp feee fawo fe foroa fo prev ppp feee fawo c jueot fo As in normal mode EINEN N OoO OoJjO O ojo smera fiss a a ert NA man awo rer jor ar EN CE ECM eR c EE tor L3 138 ar Note For the measurement of reverberation time 7R and 8R uses excitation from the internal noise generator option 9R and 10R specify impulse excitation from an external source as an impulse from a shot 61 62 Chapter 11 Memory handling Retrieving stored setups and data Measurements stored are easily retrieved To retrieve a stored setup or stored data 1 Press the RECALL key 2 Select the internal INT or the SD card for retriev ing the data by using INC or DEC 3 Follow the procedure explained in the side bar The uppermost text line in the display shows which file has been retrieved The little R denotes Recalled just like S denotes oe E 060825 0008R 120 SETUP 0006R 120
90. This way of prolonging a measurement will not activate the back erase feature see below for more on this Pausing deletes 10 seconds of the last data If you don t want this use STOP and then PAUSE CONT to continue the measurement The back erase feature When you press the PAUSE CONT key during an on going measurement the instrument will temporarily halt the measurement Pressing the key again will cause the instrument to resume the measurement while at the same time erasing the data acquired during the last 10 seconds immediately preceding the pause If the measurement has been running for less than 10 seconds when you press the PAUSE CONT key the entire measurement will be erased upon resuming the measurement Norsonic Nor140 Instruction Manual If less than 10 seconds have elapsed since the last time you resumed a paused measurement only the part of the measurement acquired since the last resume will be erased Data acquired earlier are as sumed to be accepted by you The measurement time elapsed counter will be up dated to reflect the back erase The statistics buffers optional extension will be updated similarly Displaying the functions measured The instrument measures the SPL Lmax Luin Lea Le and the Lreax Note that the SPL Lmax and Ly are all measured with the selected time constant while the rest do not make use of the time constant at all During measurements the SPL value is updated every second Once th
91. accordance with ISO 3746 and re lated Standards This means that when equipped with a Nor140 you may test the Ly of new products for the European C labelling in the production area in situ rather than in a laboratory in vitro Making measurements Before you start to make sound power measurements we recommend that you familiarise yourself with how to make regular sound level measurements Then do as follows 1 Once the test object is properly placed start the setup procedure by selecting measurement duration as described in Making simple sound measurements 2 Press SETUP followed by 4 The instrument will now enter the measurement control display 3 The Nor140 allows 1 40 microphone posi tions to be measured The initial measurement control display shows 8 positions but this may be extended to further pages covering the positions 9 40 by pressing the gt key next page 4 At the bottom of the screen the averaged sound pressure level based on the measured microphone positions is displayed Each mi crophone position is selected by moving the field cursor using the or B keys to the selected position and then pressing the START key The screen will show the normal measurement dis play during a measurement and return to the control screen and display the measured Leo value for the measured positions at the end of each measurement 111 112 Chapter 22 Sound power The measurement surface can be e
92. ance with the procedures described above An example is when the radiation pattern is shown to be symmetrical The overhead position s may be omitted for safety reasons if so stated in the relevant noise test code Mic positions one reflecting plane Each plane of the measurement surface shall be con sidered on its own and so subdivided that the result is the smallest possible number of equal sized rec tangular partial areas with a maximum length of side equal to 3d see the Fig to the right The microphone positions are in the centre of each partial area In this way the other positions shown overleaf are obtained Norsonic Nor140 Instruction Manual More than one reflecting plane For a source installed adjacent to more than one re flecting plane reference shall be made to the figures shown on this page spread for the purpose of defining a suitable measurement surface Microphone posi tions are as shown in the figures Procedure for fixing the specified microphone positions where a side of the measurement surface exceeds 3d 3d lt 3d o A 3 VI Vi lt 3d lt 3d 107 108 Chapter 22 Sound power Example of a measurement surface and microphone posi tions for a small machine and an example of microphone placement for a larger machine Details on the microphone posi tioning can be found in the ISO 3746 Microphone placement with four and three microphones for floor Ref
93. and not give the required S N ratio the value will be shown with a in the result table The other settings are described in the instruction manual delivered with the NorBuild software package Swept Sine measurement of reverberation time Click on the point for Reverberation Swept Sine in the Measurement Mode menu and follow the same selection possibilities as described above for the level swept sine measurements Speech Intelligibility by STIPA Introduction What is STIPA Speech transmission index STI The speech transmission index STI has shown to be a valuable tool for objective rating the speech intelli gibility From its first presentation in Acustica in 1971 the method has been refined and developed for vari ous applications The International Electrotechnical Commission IEC has launched the third revision of the International Standard specifying the method for calculating the index as IEC 60268 16 Essential for this development was the work carried out at TNO Hu man Factors in the Netherlands and in particular the pioneers Tammo Houtgast and Herman Steeneken The STl methods can be used to compare speech transmission quality at various positions and under various conditions within the same listening space in particular it is useful for assessing the effect of changes in acoustic properties This includes effects from the presence of an audience or of changes in a sound system The methods are a
94. and Overall Results Sound source For level and frequency analysis measurements the Dimensions SI DUI s cA E entire data set will be printed out For profile measure A DA Test conditions ments the printout will contain the periods from the d 0 uu uu present cursor position till the end of the time record Multiple sources Acoustic environment Test environment aaa Gres b oed ra Wind speed i Wind directions sukir raris s abd e laden Acoustical qualification of the test environment How to print the level the profile and the frequen Instrumentation manufacturers Instrument Norsonic AS Type 118 Ser Mo ons en cy spectrum Microphone Mersenis AS 1220 Sere LLLI Windscreen 2 42 cee sas hn A Characteristics ne uc c c e You decide what to print by what is on the display Calibration date ZU aer UII em you press the print key This means that to print the Measurenent surface Parallelepiped on three reflecting planes spectrum you must display the spectrum on the Reference box Width 5 100 a R Reference box Height 1 00 m screen to print the profile you must display the pro Measurenent Giscances 0 00 a file and so on A weighted sound power tw 73 7 dB A Surface sound pressure 60 5dB A Revirenidueal correction A Visca ali tuitidn method i Maximum C weighted Peak 99 1dB Impulsive noise Yes Transfer of data to a PC Different op
95. arity like frequency shifts and frequency multiplica tions are not treated effectively 132 Chapter 24 Speech Intelligibility by STIPA In order to fully take care of the effects of non linear ity it is important that the basic signal being modulat ed is a noise signal with a high crest factor a spectral distribution similar to the long term speech spectrum and that the main modulation frequency is selected one by one The measurement of the full STI therefore has to be performed as a sequence of measurements If each of the 98 combinations is measured for 10 sec onds the total measurement time will be about a quar ter of an hour The need for such a long measurement time in order to obtain the STI value in one position of a room limits the applicability of the full STI method The STI method may be modified in different ways to reduce the time needed for the measurement lf the system to be measured is regarded as linear then a number of solutions exist The excitation signal may be modulated with all modulation frequencies simultane ously and the components may be separated after re ception by the use of filters or Fourier analysis A more common method is to calculate the complex modula tion transfer function from the impulse response of the room If the impulse response can be regarded as a well behaved room response with an exponential decay ing envelope characterised by the reverberation time the modulation trans
96. artridge this will typically amount to 0 2 dB lower for calibrators producing a 1000 Hz calibration signal e g the sound level meter should then be set to 113 8 dB when using a 114 dB 1000 Hz sound calibrator Other frequencies will require different correction values see the Field calibration side bar overleaf for more on this or use the numerical keypad to key in the sensitivity gt lt a Field calibration The recommended sound As calibrator for verification of the sound level Z meter Nor140 is the Norsonic Nor1251 with a nominal sound pressure level of 114 0dB 1kHz In order to compensate for diffraction effects around the microphone we recommend adjusting the sound level meter to indicate 113 8dB random correction off If random is on adjust to 114 0 dB If other types of calibrators are to be used for the cali bration we recommend adjusting the sound level meter to indicate the following levels referred to the sound pressure level acting on the microphone s diaphragm diffuse correction off f Hz 125 250 1000 4000 8000 Corr dB 0 0 0 0 0 2 0 8 2 8 The diffuse correction is activated and deactivated in the Corrections menu Press SETUP gt 1 instr gt 6 Correct Correction Random Windscr ON Preamp ON S noise ON 1 Corr par BIBRWGS Navigate in the menu using the arrow keys and use INC or DEC to activate deactivate the Random setting Activated Random setting
97. asic time profile mode the instrument logs the A weighted equivalent leval the A weighted maximum sound pressure level and the Z or C weighted peak level At the same time the global mode measures the instantaneous SPL the maximum and the minimum SPL the equivalent level the sound exposure level and the maximum peak level All the global levels are measured as A weighted and Z or C weighted levels Norsonic Nor140 Instruction Manual Presenting the L t as a table Numerical presentation of the acquired data works even here Press TBL while in A profile mode to pro duce the table This can be done during as well as af ter a measurement An example of the table is shown in a side bar on the preceding pages Use WA keys to move the cursor up and down but only after the meas urement have ended 41 42 Chapter 7 Enhanced time profile measurements Enhanced time profile measurements The optional extension 7 enhanced time profile lets task Deactivate those that you won t need A 1 you select the functions to be measured as a function means activated and a 0 means deactivated of time Select from A weighted functions as well as C or Z weighted even A weighted peak Furthermore 3 Both the A weighted and the C or Z weighted func enhanced profile opens up for the use of source cod tions and filter bands if available are accessible ing see Adding markers for details Apart from this from
98. ave band number k used to mimic the masking effect in the auditory or gan The value is a function of the level in the adjacent lower octave band An alternative to keying in the levels for the background noise is to use values from a previously stored meas urement The measured levels must have been made in 1 1 or 1 3 octave bands Press RECALL while the table for the background noise is displayed Select the requested file from stored results and press ENTER to read in the data Values measured in 1 3 octave bands are recalculated to 1 1 octave values NOTE You may obtain the averaged level from different measurement positions by making a normal measurement in the first position then move to the next and press CONT for prolong ing the measurement time Real background noise If a real background noise is present during the meas urement the effect of the noise will in most cases be treated as noise according to the STIPA method and lower the STl value However some noise signals may be interpreted as a STIPA excitation signal giv ing wrongly a modest STI value The instrument is pro grammed to detect such situations and place a ques tion mark adjacent to the indicated value However not all cases can be detected properly To investigate such potential problems we recommend making a meas urement without an excitation signal If this STI value is low or considerably lower than the value measured with the excitation signal
99. averaged levels However for some applications the measured differences from a set of measurements should be averaged This may be obtained in the following way Measure the level in the source and receiving room L and L and store the result Move the cursor to the RESULT field and press DEL Then confirm that all averaged values shall be deleted Repeat the meas urements of levels in the source and receiving room as many times as requested including the required number of reverberation time and background meas urements in at least one of these repetitions When all measurements are finished make RECALL of the first serie Move the cursor to one of the fields L L T or L and press RECALL for adding the initial result and press ENTER Enter other set of measurements in a similar way After each recall the displayed number of differences ND is increased as shown below No val ues will be given for the individual levels L L or L The results are calculated and displayed as before Averaging level differences Airborne V 72 2 mc S 9 6 mC L1 REE L2 T N 2 Lb N 0 Results Criteria Impact sound insulation Impact excitation The impact sound shall be generated by the standard tapping machine as specified in ISO 140 7 Measure ment of sound insulation in building and building ele ments Part 7 Field measurement of sound insula tion of floors For isotropic floors a single position for the tapp
100. band or third octave band measurements the choice is yours depending on how you prefer to configure your Nor140 The octave band measurements span the range 8Hz to 16 kHz or from 0 5 Hz to 16 kHz dependent on your set up An upgrade to option 3 will provide you with third octave band measurements in the range 6 3 Hz to 20 kHz or from 0 4Hz to 20 kHz The two bandwidths share the type of functions measured In a single frequency analysis the Nor140 measures e SPL The Instantaneous Sound Pressure Level Lmax The Maximum Sound Pressure Level e Lun The Minimum Sound Pressure Level e The Integrated Equivalent SPL e Le The Sound Exposure Level While the measurement is running the instantaneous SPL is available for inspection but as soon as the measurement is terminated the SPL becomes mean ingless and therefore not listed in the result tables If your Nor140 is equipped with parallel time con stants option 5 the list of functions measured simul taneously can be expanded to include functions with F S and time constants at the same time The frequency bands measured are all visible in the display with no need for horizontal scrolling The fot key lets you enter and exit the spectrum display Furthermore the instrument measures the selected full frequency range every time Given the high dynamic range 120 dB which eliminates the need for adjust ing the gain there is very little to set up before a fre quency
101. being used place the sound source on the axis of the appropriate microphone at the nor mal speaking distance measured from the lip circle for the artificial mouth or acoustic centre of the loud speaker and direct it in the normal speaking direc tion Connect an appropriate CD player to the sound source Set the speech level Switch on the sound level meter and ensure that it is properly calibrated Play track 2 with the STIPA excita tion signal and adjust the level to the required speech level normally 60 dB at 1 m from the sound source 66 dB at 0 5 m Alternatively track 1 with the sine ex citation may be used both should produce about the same A weighted level After setting the speech level play the STIPA exci tation signal on Track 2 during the measurement 70 minutes The standard IEC 60268 16 recommends that the excitation spectrum is correct within 1 dB for the ap plicable frequency range Select the STI mode The STI mode is one of the modes of operation for the Nor140 instrument By selecting this mode the instru ment will automatically be configured for STI measure ments For selection press MODE after switching the Norsonic Nor140 Instruction Manual instrument on and select STI by pressing the numeric button 5 After the selection the instrument is ready for a STl measurement A sign in the upper left corner of the display indicates the STI mode of operation The instrument screen will s
102. cccnnncccnononcccnnnnnnonorcnnonnrnnnonn cnn nano nnne nnne tenen Caleulatirig the tesults eas cette ot tch seme taedet omm E bc Lied ttim em Chapter 24 Norsonic Nor140 Instruction Manual Service equipment sound pressure levels Survey MethOd ccceeceeseceeeeeeteeeeeseeneeteentesteeetes 128 R miote Operation roma PO icit merae d eben 129 Swept Sine measurement technique sse eene enne 129 Swept Sine measurement of sound level sss 129 Swept Sine measurement of reverberation time eee 130 Speech Intelligibilityby STIPA Introduction What is STIPA speech transmission index STI ner eee ete e i pene cod eps 131 DEVCIODIMEMEORS Tih e E 131 RASTIand STIBA n e ee eene dn D Ee a a depu tee ies 132 How s TIPAmeassuted scc cette tc es des ner t coti e ues c e eost a ea e CE venies 133 Sehr 134 Unitsincluded in delivery a cH re gis RR e UH EHE or pce Ren 134 Software option for Nor140 no n c nen n Lo aea eem i ede Hacen 134 O ELLE T 134 CD with Excel Sheet tec dr asa 134 MeasuremerntoverViewW snis osse ie i eei BO RR tao iia 135 General instrument description cnc c RU GR TUE RE De Re need ee 135 Selecting a loudspeaker for the excitation sssssss eee 136 Loudspeaker orelectrical excitation s eere ee e ence te eec dun 136 Pertormirig a measurement erac SO a N Re RU ERN n EN tete 137 Set Up sos Ge redea Teeth eta eel sees A a Se ee
103. ch level Press TBL once more to obtain the modulation indices and bring the values into the appropriate cells You may then enter values for the background noise and see how this will affect your reading The values from the STIPA measurement may be transferred to the PC by using the USB or serial inter face on the instrument A transfer program like NorXfer may be used STI Calc On the CD with STIPA calc you will also find a program called STI calc This program may be used to estimate the STl value based on information on the octave band levels for speech and background noise and the reverberation of the room also in octave bands The applied formulas assume linearity and that the impulse response for the room is well behaved without signifi cant echoes The calculation should not be used as a replacement for a real measurement of the STI value 141 142 Chapter 24 Speech Intelligibility by STIPA Specifications The STl value is measured according to the require ments for STIPA method defined in IEC 60268 16 Ed 3 0 2003 05 Sound system equip ment Part 16 Objective rating of speech intelligibility by speech transmission index The method specified in the International standard is extended with the option for background noise correc tion The ClS value is calculated from the STI value as specified in IEC 60849 Ed 2 0 1998 02 Sound systems for emer gency purposes FFT measurement mode Introduct
104. cy spectrum display mode the functions will appear in the following sequence Lea Lmaxe TT Line P Le Lpeak 7 Lmaxs 7 Lins SPL me Accessible during measurement only not after 3 Func L J ea so Lun 4 Lux Leal 34 Chapter 5 Frequency analysis Displaying the result tables To switch between A and me C or Z weighted values use Leg 56 0 Sound level meter the NETW key PME 592 display mode Banki 965 20 pee 0 05 CF L 03 amp L 10 L 5 0 57 5 E eS L10 0 amp 57 1 SE L50 0 56 0 L90 0 54 8 L95 0 54 5 rs En L99 0 53 9 1 TBL ES Statistics is optional Units not configured for the German gt speaking markets will 2 tot have tables without Leq Leql and Tmx5 values Use the vertical cursor keys to Use the vertical cursor scroll the centre keys to change the fre frequency up and Use the FUNC key quency band down to select function Spectrum display mode ANN Y 13 0 13 0 13 1608 14 26 07 AF SPL 115 4 AR ws 4 1B BL Statistics is optional Statistics displaying the percentiles Instruments equipped with the optional extension 4 statistics will measure the statistics every time This cannot be switched off The sampling for the statistical calculations is made with F time constan
105. d Norsonic Nor140 93 Instruction Manual S YA Marks on the lower line of the display Marks for the applied corrections are found on the lower line of the display Random incidence correction ON Wind screen correction ON Preamplifier correction ON Self noise correction ON 230037 Wind screen correction ON In addition you may find the following marks on the lower line dB The signal strength is indicated as a level in decibel The reference level is normally 20 uPa for sound pressure levels EU Engineering unit The signal strength is indi cated in a generic linear unit The actual unit could be voltage referring to the voltage on the input terminal or ms if an accelerometer is connected to the input Numerical keyboard The number printed on the keys are entered if you press one of the keys on the keyboard E A numeric value has been entered The instrument expects that you press ENTER to confirm the number 94 Chapter 21 Reverberation time measurements Reverberation time measurements The optional extension 9 for the Nor140 permits meas urements of the reverberation time The reverberation time is simultaneously measured in every frequency band The calculation algorithm used complies with the requirements set by ISO 354 2003 Acoustics Meas urement of sound absorption in a reverberation room and ISO 3382 1997 Acoustics Measurement of the reverberation time of rooms with reference to
106. d octaves Units without filters will cal culate the broadband values A and C or Z weighted values As usual this is an optional feature so if you don t need it you won t have to pay for it either The reverberation time algorithm may be based on the integrated impulse response method or the inter rupted noise method Hence impulses are required as excitation signals or noise excitation from the internal signal generator may be applied 3 4 Chapter 1 Introducing the Nor140 Noise monitoring and mapping The large memory and the time synchronising capabilities of the Nor140 makes it well suited as a front end in noise monitoring systems outdoors for community noise as well as in doors in workshops etc The high dynamic range 120 dB makes the setup easy and ensures reliable measurements in all situa tions The Norsonic product range contains a wide range of equipment and accessories for use with noise moni toring and measurements We supply enclosures for permanent monitoring installations environmental cases for semi permanent installations microphones for applications in tough environments cables mo dems weather stations and post processing software A detailed presentation of this is available in a separate leaflet and on www norsonic com Real time frequency analysis The all digital technology used in the Nor140 made it natural to include filters an important input from many of our customers Octave
107. define the duration and the resolution 1 Press SETUP gt 2 Units with the option 7 installed will then produce the measurement duration menu See side bar for details 2 Set the global duration 3 Move down to resolution and set as required Navigate and leave the menu as usual Option 7 permits the time resolution to be as low as 50 ms See text for details Meas dur Duration 000 00 Resolution Here the resolution 125ms is set to 125ms N 40 Mx 68042 WS 44 Chapter 7 Enhanced time profile measurements Nt 4 Y No back erase in profile pause mode Ay The resumption of a paused measurement will F cause the ten seconds acquired immediately before the pause to be erased This applies to the global measurement but not to the profile Assume you have set up the measurement to also include profile and that the measurement is running If you press PAUSE CONT the global data acquisition will be halted but the profile will still acquire data These data will be marked P for pause to denote that they were acquired in pause mode and that they do not participate in the global level assessments N o The line denotes periods are i The pause marker marked oga A APeak 72 Mk P WS When you later press PAUSE CONT again to resume the amount of periods marked as paused will be expanded backwards in time to include periods acquired in the time span subject to back erasure in th
108. display mode or from frequency spectrum mode The tables are available during as well as after a measurement Remember that SPL values are shown during the measurement only The tables available are shown in the side bar Displaying the result tables v gt Instruments configured for the German speaking markets will measure Ley with time constant and Tuas with F time constant in addition see below ay TAN The functions are available sequentially To display a certain function press the FUNC key repeatedly until the function appears The sequence is as follows mz Log 3 Lmax E SPL 3 FUNC La Leg Le Accessible during measurement only not after Norsonic Nor140 33 Instruction Manual ss Ay The Lreax and Tmaxs are not accessible when the spectrum is displayed Units configured for the German speaking markets If also equipped with Leg and Tuas the sequence is as follows press FUNC key repeatedly a Leq DP Lux P Lun SPL 3 Func Limaxs Z Leal Lec Le Accessible during measurement only not after Units equipped with multiple time constants Units equipped with multiple time constants will measure SPL Lmax and Luin with all three time constants F S I employed simultaneously In sound level meter display mode use the FUNC key to produce the function and then TC key to display values with the different time constants In the frequen
109. e sources There are environmental requirements that should be satisfied for the value of d selected In brief the environmental requirements state that the reflecting plane must not be of such a material or in such a condition that it radiates any appreciable sound energy due to vibration If the measurements are made outdoors over grass or snow covered ground the measurement distance shall not exceed 1 metre The general requirement is that the sound absorption co efficient of the reflecting plane shall be less than 0 1 over the frequency range of interest Also no reflecting objects that are not part of the source under test shall be located inside the measurement surface Microphone array on the parallelepiped valid for larger machines Microphone positions The microphone positions lie on the measurement surface a hypothetical surface of area S enveloping the source whose sides are parallel to the sides of the reference box and spaced out a distance d measure ment distance from the box The microphone positions on the parallelepiped measurement surface are shown on the following pag es The area S of the measurement surface according to the microphone position figures is given by the for mula S 4 ab bc ca where a 0 51 d b 0 5l d and c 0 51 d and I and l are the length width and the height of the reference box If a source is installed adjacent to more than one reflecting plane reference
110. e PA system is strongly non linear or suffers from limited bandwidth In order to improve the accuracy in the intelligibil ity assessment the STIPA method was developed It handles effects due to reverberation in the room and distortions commonly found in public address sys tems It also performs well for room acoustics and can therefore in nearly all cases replace the RASTI method and deliver results more closely to the values obtained by the full STI method The measurement time for a STIPA measurement is similar to the RASTI method 10 15 sec Norsonic Nor140 Instruction Manual The STIPA method uses a higher degree of modula How is STIPA measured tion for each test frequency It will thus be more robustfor The instrument option comes complete with a CD con interference from non stationary background noise See taining the excitation signal The excitation is played figure below for a comparison between the methods continuously through a loudspeaker and this act as a talker For aSTI measurement all carrier frequency bands are modulated with all modulation frequencies in total 98 modulation indices For RASTI two carrier frequencies are used giving 9 modulation indices For STIPA 12 modulation indices are measured from the complete range of carrier frequencies Carrier frequency Hz Carrier frequency Hz Carrier frequency Hz EEES OC Xt 2c oc oc LO Hita 00 a dde T iNJ Oj cau st co
111. e been stored the instrument may start to measure for another period of the same dura tion and then store the acquired data start again and so on The snag however is that a little time will always be spent on storing the acquired data This means that if you for example set up the instrument to measure in periods of an hour and start the measurement exactly on the hour the measurement period start time will ex hibit a lag after some hours of measuring typically 3 4 seconds per individual measurement If this lag is unacceptable for you we recommend that you use the synchro feature When activated the synchro will stop the measurement slightly earlier some seconds to give room for data storage and housekeeping so that the measurement will start ex actly on the hour Available storage modes The Nor140 will always operate in one of four available storage modes These are e Manual which requires that acquired data are stored manually by the operator before the next measurement is made e Automatic which causes the acquired data to be stored automatically upon measurement termina tion regardless of the reason for termination irre spective of whether termination took place because the duration expired or because you pressed stop e Repeat which causes the instrument to store the acquired data and then restart immediately and make another measurement using the same meas urement setup and duration Repeat applies
112. e documentation accompanying your sound use the INC and DEC keys while at the same time watching the level read out Alternatively you may key in the required sensitivity using the numerical keypad Once the correct level reading is estab lished press enter to leave the menu calibrator 2 Enter calibration mode Press the CAL key to gain access to the Calibration menu The display will typically look as shown to the right Note Never calibrate the instrument before three minutes after switching the instrument on The sound calibrator should be mounted onto the microphone as shown here 3 Know the output level of your sound calibrator Some sound calibrators have an output level of 94 dB while others like the Nor1251 which is used rM in the example to the right have an output level of Sens 114 dB Some have an output of 124 dB like the PEN db Nor1253 Unless you know the output level of your F Lev sound calibrator you won t be able to know what level the measuring instrument is supposed to show The output level is normally printed on the sound calibrator or stated in its accompanying user documentation C 1 1 3 8 se these keys to adjust he sensitivity HER cs cC 4 Free field microphones require lower settings Be aware of the fact that instruments using free field microphones shall be adjusted to a value slightly lower than the output level of the sound calibrator For a half inch c
113. e end of each period Copy the setting to Prnt Xfer Upon leaving the functions to log menu you will be prompted to decide whether the settings you made shall apply to the functions to print or transfer In order to avoid being totally drowned in values you may set up instrument to just print a few of the functions measured However for convenience we offer the feature of setting up the same functions for printing as for measurement If you then want to print fewer functions just go to the print functions setup menu and deactivate those you won t need To produce the print functions setup menu e Press SETUP gt 1 gt 9 gt 1 Functions to be printed are denoted by a 1 dye The time constant cannot be set from Pd PA inside the L t par menu Instruments which are not equipped with multiple time constants will make use of the time constant currently selected If this is not the one you want to use for your profile meas urements you must change it This cannot be done from within the L t par menu Leave the menu and change the time constant by means of the TC key Norsonic Nor140 43 Instruction Manual The same applies to the transfer of measured function values to your PC You may not want to have all the data transferred so you can set up which functions whose values you want to transfer To produce the transfer functions setup menu e Press SETUP gt 1 gt 9 gt 2 Setting the time resolution To
114. e global mode The reason why we designed it this way was to provide you with the complete overview if you later transfer the acquired data to your PC you will be able to do calculations on any parts of the profile while at the same time you ll be able to see the intervals that didn t take part in the global assessments Consequently the duration of the measurement will seem ambiguous The global duration will be less the pause and less any back erase while the profile will have a duration including the pause length and without back erase If you have set up a profile resolution different from i e shorter than the global measurement duration the instrument will log the time profile in addition to the global measurement The enhanced profile offers a time resolution period length down to 50 ms Between 50 ms and 1s the resolution is adjustable in 25 ms steps Above 1s the step size is 1 s as is the case for the basic profile Setting a period length better than a second e Set the resolution to 1s and press the DEC key to enter the ms area Scroll down to the required setting or use the numerical keypad as usual after the ms sign appears Note that if you keep the DEC key or the INC key depressed it will after a while speed up the scrolling or Key in 59 s as the resolution and then press ENTER followed by INC the resolution will be set to 50 ms immediately Press INC to adjust or use the NUMERICAL KEYPAD to set t
115. e measurement is over the SPL becomes meaningless A single SPL value can not be used to characterise the measurement unless it represents some kind of maximum minimum or time integrated average lt is thus not accessible post measurement The functions are available sequentially To display a certain function press the FUNC key repeatedly until the function appears The sequence is as follows d Leq Lmax EL SPL FUNC Lmin Lre G Le EM Accessible during measurement only not after 23 24 Chapter 4 Simple sound measurements Units configured for the German speaking markets If also equipped with Leg and Tmaxs the sequence is as follows press func key repeatedly a Leq gt Lmax gt Lmin SPL 3 Func Tuas 7 Leg Leg 7 Le Units with multiple time constants Units with multiple time constants will measure the Lmax and Lun with all three time constants F S 1 employed simultaneously During but not after a measurement the SPL will also be available for display To view one of the functions as measured with another time constant use the FUNC key to produce the func tion and then press the TC key once or twice Displaying the result tables As an alternative to the above procedures you may display all the data in a single table Press the TBL key to produce the result table This feature is available during as well as after a measurement Do not forget that SPL value
116. e parallel 1 1 octave 2nd network Z The orientation of the instrument in the magnetic field had no influence During the ESD test the SPL value may show some fluctua ions from the ESD pulse Power supply Battery voltage 4 6 4V External DC voltage 11 16V This Declaration of Conformity does not affect our warranty obligations AS ka Tranby October 2006 Dagh ds Dagfinn Jahr Quality Manager The declaration of conformity is given according to EN 45014 and ISO IEC Guide 22 Norsonic AS P O Box 24 N 3421 Lierskogen Norway NN Norsonic P O Box 24 N 3421 Lierskogen Norway Tel 47 3285 8900 Fax 47 3285 2208 info norsonic com www norsonic com Norsonic AS supplies a complete range of instrumentation for acoustics from sound calibrators micro phones amp preamplifers via small handheld sound level meters to advanced yet portable real time analysers but also spectrum shapers building acoustics analysers and complete community industry and airport noise monitoring systems Contact your local representative or the factory for information on our complete range of instrumentation
117. e positions are found by sequential pushes of the TBL key The results may also be copied to a printer The report includes necessary spaces for all the required meas urement information to be written directly on the report by the user On a second page the individual results for each of the microphone positions are printed See Making hardcopies for more on this On the previous pages you will find display exam ples together with the calculation procedure for the de termination of the environmental correction factor Ko which has been repeated from the previous chapter for your convenience Building Acoustics Introduction When equipped with the required program options Nor140 is well suited for measurement of building acoustics in the form of measuring reverberation time and sound insulation The Building Acoustic Survey mode allows meas urement of building acoustic parameters according to the International Standard ISO 10052 2004 12 Acoustics Field measurement of airborne and im pact sound insulation and of service equipment sound Survey method These measurements are made in full octave bands and the results are reported for each band as well as frequency weighted values according to ISO 717 1 and ISO 717 2 Menu for Mode menu measurement task MODE Survey met 1 Normal 1 Airborne 2 Rev 2 Impact 3 Power 4 BuildAc Eng met 5 STIPA 6 FFT 3 Airborne 4 Impact BURWGS W Ed
118. e required excitation ignal Nor1033 n Measurement of sound level As stated in the standards the spatial average of the sound level in the room is required For survey meas urements this may be achieved by measuring the lev el while moving the sound level meter microphone around in a figure of eight trajectory Recommended measuring time is 30 seconds For the engineering method point by point measurements has to be applied and the instrument will calculate the averaged level The level measurements may be performed in the normal mode of operation and storing the results for later processing or alternatively the measurement may be started from the calculation menu when the result is required for the calculation Press SETUP to enter the menu for setting the measurement time Measurement of reverberation time For a survey measurement according to ISO 10052 the corrections for the acoustic absorption may either be based on measurement of the reverberation time or based on estimation based on room type type of surface and furniture Both methods are implemented For engi neering measurements according to the ISO 140 series of standards the reverberation time has to be measured If a measurement is required the reverberation measurement may be performed in the reverbera tion mode of operation and the result stored for later processing MODE 2 Rev Alternatively the meas urement may be started from the calculation m
119. e sound insulation The following terms are used in the display L average sound pressure level in the source room during excitation dB L average sound pressure level in the receiving room during excitation dB Lp average background sound pressure level in the receiving room dB T reverberation time in the receiving room s To reference reverberation time equal to 0 5 s k reverberation index dB Dit level difference dB standardised level difference dB D normalised level difference dB R apparent sound reduction index dB V volume of the receiving room m S area of the partition between the source and re ceiving room m Ao reference absorption area equal to 10 m The relations between the quantities are given by the following equations kem T AT D L L sero The values are calculated for each octave or one third octave band For Dw D and R a single number value is also calculated The value corresponds to the 500 Hz value for the reference curve after shifted it in accordance with the method specified in ISO 717 1 or ISO 717 2 as appropriate The spectral adaptation terms C and Cy are also calculated according to the same standards Terms and definitions for impact sound insulation The following terms are used in the display L average sound pressure level in the receiving room during excitation dB Lp average background sound pressure level in the receiving room dB
120. e time constants will always employ all three time constants F S and 1 for all measurements The time constants apply to the SPL the Lmax and the Lmin functions Lea Lpeak and Le do not make use of time constants Units configured for German speaking markets will also measure the Leg The presence of multiple time constants eliminates the need for setup of the time constant Norsonic Nor140 Instruction Manual Multiple time constants and statistics Observe that the statistics buffers optional extension will be based on sampling using time constant F This cannot be changed by the user C or Z as spectral weighting network The Nor140 has three spectral weighting functions in addition to the filter bands These are A weighting and C or Z weighting The Z weighting is a replacement for the previous Flat or Linear spectral weighting functions A problem when dealing with the Flat and Linear functions has been that none of them are properly defined in any standard The Z spectral weighting circuitry is flat within at least 16Hz to 16kHz in the Nor140 it extends far beyond that and is defined in the International standard IEC61672 1 The Nor140 can make use of two of the three spectral weighting functions simultaneously viz A weighting and Z or C weighting To specify whether to use Z or C weighting e Press SETUP gt 1 instrument gt 5 2nd netw and navigate in the menu as usual Press ENTER twice for return to
121. e used To start a measure ment press START when the field cursor is in the field for reverberation time marked T When the required information has been entered the cursor will automatically be placed in the field for calculation of the final result If you are satisfied with the entered values press ENTER or if you want to make any correction move the field cursor to the re quired field and enter the corrected values or press DEL to clear averaged values When you move the field cursor to the field Results and press ENTER the following functions are calculated for each of the one third octaves bands 50 Hz to 5000 Hz Norsonic Nor140 Instruction Manual e The normalised impact sound pressure level La e The standardised impact sound pressure level Lar e The averaged room level L corrected for back ground noise e The reverberation time T For the values L and Lar a frequency weighted value according to ISO 717 2 is also calculated Pressing the FUNC key repeatedly will display the different functions The weighted values are all rounded to the closest whole dB If you want to go back to the menu for calculation press ENTER Press the MODE button if you want to return to nor mal mode of operation Store and recall You may store the result by pressing STORE The file is automatically designated with the next free file number succeeded with the letter B indicating build ing acoustics Partly
122. e user defined percentile This means that you may change the percentile as many times as you want For stored and later recalled data any changing of the user editable percentile is no longer possible The percentiles table sequence E 120 00 00 30 0 14 ISPL alte C A 3 4 E 40 5 ws 8 jo EE t q E 0 05A E 100 Ss o Leq 37 9 3 A Q FMax 39 5 S SY FMin 37 3 3 E LE 44 0 o z Peak 53 5 E ILeq 46 4 gt F Tmx5 39 5 5 F SPL E 0 05 CF L 03 L 10 L 5 0 57 5 L10 0 37 1L L50 0 56 0 L90 0 54 8 L95 0 54 5 L99 0 53 9 m ES 25 26 Chapter 4 Simple sound measurements Editing the user defined percentile To enable the editing the instrument must display the percentiles table In the percentiles table press the K key the end left key to enable this Once the percentile field is shown inverted with white text on black background the text can be edited using the numerical keypad or INC and DEC If you use the numerical keypad you must press ENTER to confirm that you have keyed in the new percentile To terminate the editing process press the b end right key The corresponding percentile value will now be displayed given that the measurement duration was long enough to provide a sufficient number of samples AF E 0 21AF rw LEBEN JM L 10 546 L 5 0 51 7 134 99 1L10 0 481 a L50 0 44 1 L90 0 43 5 L95 0 4
123. easurements The measurement duration setup menu Total global duration Meas dur of measurement Duration Selected resolution 00 00 05 No of periods with lution selected duration and 00 00 resolution Max No of periods N 5 depends on the __ Mx 707174 amount of free memory available The profile resolution does not have to be selected so that the global duration becomes a multiple of the profile resolution The last period will be truncated if the dura tion divided by the profile is not an integer o Z Which resolution should you use V This will always be a trade off between the e need for information and the amount of data generated You should also take into consideration the global duration of your measurement For example you may want a higher resolution in a 1 minute measurement than in a 24 hour measurement Will you need a 1 second resolution for 24 hours It s going to be a lot of information to go through after wards No absolute rules or guidelines can be given since there are so many different applications and require ments en Y indicated by a 2 The time profile display The A indicates profile global is Display top scale 120 Spectral weight Graph cursor 7 ing function Use lt gt keys to applied to the move the cursor righthand along the graph 0 bargraph This feature is not available during a meas Peak 74 9 Measurement urement
124. ected reference value for the level The decay corresponas to the expected decay based on the classical method which conventionally is ap proximated by a straight line Due to the fact that the running time t is the lower start point for the integration the operation of the for mula in the equation may be described as backward integration In an alternative form of the formula the in tegral starts at oo and runs backward to the actual time Historically this was achieved using analogue technol ogy by playing a tape with the recorded response in the reversed direction The formula does not consider the extraneous noise normally accompanying a measurement When a fractional octave band filter is a part of the measured system the formula will describe the ex pected decay according to the classical method for the applied filter band The difference between the classical and the Schroeder method may be illustrated by the figure on the adjacent side For the classical method a the averaged decay is obtained by averaging a number of measurements For the Schroeder method b the expected decay is obtained by processing of the im pulse response h t Implementation in Nor140 When the instrument is set up for measurements of reverberation time based on impulse excitation the instrument starts logging the level in each octave or 1 3 octave band with a time resolution of 5 ms Each sample will represent the Leq value for each 5 ms
125. ed levels as functions of time in parallel with the overall frequency analysis described in this chapter Details on the logging of the level vs time can be found in the chapters Basic time profile measurements and Enhanced time profile measurements Measurement duration SETUP 1 Instrument menu Time profile option 6 2 Meas duration lled 3 L t params installe 4 Fregency mode 5 Level range 6 Trigger T Noise gen 8 Recording 9 Reference tone Meas dur Meas dur WS Duration Duration 00 05 HU 00 05 tesolution 00 00 05 Time profile not N 66 installed Mx 1103786 P P 28 Chapter 5 Frequency analysis Statistics Even if your instrument is equipped with the optional extension 4 statistics the percentiles table will fail to produce values for all percentile settings unless the measurement duration is sufficiently long see the Missing percentiles side bar in this chapter for more on this Instruments with time profile installed If your instrument has the time profile installed and you don t require it you should set the resolution to the same value as the duration to keep the instrument from logging the level as a function of time like the classic level recorders used to do Unless you want this to take place of course Cf Basic time profile measurements Enhanced time profile measurements and Multispectrum meas urements for details on logging the
126. ed with Uc 0 95 SIS nz 10 0 78 AIBRWG voice The corresponding ClS value Common Intel ligibility Scale according to IEC 60849 1998 02 is also indicated The mean A weighted speech level is indicated in dB relative to 20uPa If the measured value is detected as unreliable a question mark is placed behind the indicated value for STI and CIS The speech level for each octave may be displayed by pressing TBL A second press on the TBL button displays the modulation indexes for each of the STIPA octaves The combined value for the double octave 125 Hz and 250 Hz is listed as 250 Hz The number below each octave frequency is the modulation frequency in Hz The corresponding uncor rected modulation index is displayed to the right Press the key TBL again to display the highest frequencies Press the TBL button once more for return to the main display NOTE We recommend that from time to time you test your CD player loudspeaker and sound level meter under close to ideal condi tions Such a situation exists just in front of the loudspeaker placed in a large room when the back ground noise is considerably lower than the excitation signal Adjust for a level between 60 and 70 dB In this case you should obtain a STI value close to one Store and recall the result After the measurement is performed the results may be stored in the non volatile memory of the instrument or on the SD card this is done by pressing the button
127. element so the acoustical centre is well defined IEC 60268 16 recommend using a loudspeaker with a cone diameter of maximum 100 mm and refers to ITU T Recommendation P 51 describing an artificial mouth A sound source according to this specification is available from different manufacturers with a typical example being the GRAS 44AA When speech is relayed through a sound system a simulator is not normally required unless a close talk ing or noise cancelling microphone is involved Loudspeaker or electrical excitation Most applications require that the excitation is per formed using a small loudspeaker acting as a human talker However same applications such as testing public address or voice alarm systems are more con veniently tested with the electrical signal from the CD player fed directly into the system to be tested In a similar way some applications related to test of transmission channels require an electrical signal as the input to the sound level meter for analysis For this application the microphone preamplifier may be sub stituted with a cable to the input socket of the sound level meter NOTE For this description a measurement set up with acoustic excitation and detection using the normal measurement microphone is assumed Performing a measurement Set up Set the sound source artificial mouth or suitable test loudspeaker in the normal position for the speaker If a sound system is
128. elocity is therefore 0 1ms 2n 7943 5 0 0002 ms TT 9 The corresponding vibration displacement is 0 1ms 2n 79 43 s z 0 0000004 m 0 4 um Calculation of frequency weighted acceleration Different types of frequency weightings are in use for obtaining a single value for the vibration severity The international standard ISO 8041 specify nine different frequency weightings related to human response to vibration The different time averaged weighted accel eration values may be calculated from the levels in the 1 3 octave bands 149 150 Chapter 26 Measuring vibration using Nor140 If the acceleration in i frequency band is a and w is the weighting factor for that band the weighted acceleration a will be given by a Equ a I The values for w are found in ISO 8041 and depends on the selected weighting Technical specifications Unless stated otherwise the specifications are for the complete sound level meter Nor140 equipped with mi crophone type Nor1225 and microphone preamplifier type Nor1209 Values are based on the sensitivity set to the nominal value for the microphone 26 0 dB cor responding to 50 mV Pa A microphone cable Nor1408 of length up to 20 m may be used between the microphone preamplifier and the instrument body without loss of performance Longer cables may be used if maximum sound pres sure level or frequency is reduced The definition of terms is based on I
129. ement has been ended or stopped The status of the Go NoGo comparison is displayed as a Go or a NoGo symbol within the L f display As the Reference Spectra only contain dB values the currently selected spectra function Leq Lmax Lmin etc selected by the FUNC key will be the basis for the comparison of the actual measurement spectrum with the currently stored and selected Reference Spectra All frequency band values of the actual measured spectrum must fulfil the actual requirements of the saved Refer ence Spectra in order to get a Go status In cases where all frequency bands must be above or below the Reference Spectrum in order to get the desired Go NoGo status a selection of the respec tively Lower or Upper Reference Spectrum as limits will perform the required operation Alternatively selecting both the upper and lower Reference Spectra requires that the measured spectrum must be between these two Reference Spectra for all frequency bands that contain values Digital output lines One of the digital output lines of the I O socket may be set to follow the Go NoGo status Hence this out put pin goes high when any frequency band within the measured spectra is above the upper reference spec tra or below the lower Reference Spectra If only one of the Reference Spectra is activated only this spectrum is considered for the digital output status See setup of digital I O A digital output line of the I
130. enerator is installed it may be used for ex citation otherwise impulse excitation has to be used For starting a measurement press START when the field cursor is in the field for reverberation time marked T If you want to estimate the absorption as described in ISO 10052 move the cursor to the field marked E and press ENTER By specifying the type of room and the covering for walls ceiling and floor you are enter ing data corresponding to Table 3 in ISO 10052 When the required information has been entered the cursor will automatically be placed in the field for calculation of the final result If you are satisfied with the values press ENTER or if you want to make any correction move the field cursor to the required field and enter the corrected values Note that you have to be in the menu for entering values before you are able to select another mode 123 124 Chapter 23 Building Acoustics When you move the field cursor to the field Calc re sult and press ENTER the following functions are calculated for each of the octaves bands 125 Hz to 2000 Hz e The normalised impact sound pressure level La e The standardised impact sound pressure level Lar e The receiver room level L e The reverberation index k e The reverberation time T For the values L and Lnr a frequency weighted value according to ISO 717 2 is also calculated Pressing the FUNC key repeatedly will display the different function
131. enu when the result is required for the calculation Airborne sound insulation Airborne V EEEX r C S 5 6 mc L1 L2 T E Cale result BiRWG Calculating the Airborne Survey result After selecting the Building acoustic mode select 1 Airborne in the display shown on adjacent figure Enter the value for the room volume V and press ENTER or move the field cursor to C and press ENTER for a calculator The calculator allows you to enter the length width and height of the room in metres in order to calculate the volume After the volume is entered the field cursor automatically moves to the next parameters to be entered Area S Enter the value or use the calculator The field cursor automatically moves between the fields as values are entered If you want to adjust any previously entered value use the cursor keys to move the field cursor to the required parameter The next set of values to be entered is the sound levels in the source room L for each octave band Recall a measurement by using the RECALL key or press START for starting a measurement The values are automatically stored The sound level meter should be moved as specified in the measurement standard to obtain the spatial average The set of levels in the receiver room L is obtained in a similar way Estimating the correction for the acoustic absorption Estimate k Room type Furnished Kitchen Ba
132. er When MANUAL trigger is selected the measurement will start immediately after the START key is pressed This corresponds to the way of operation before the trigger option was installed Clock trigger Move the field cursor to Clock and then press 1 to select the menu for setting the time for starting the measurement The display below will be shown Use the P cursor keys to select the field for hour minutes Setting the time for the clock trigger Meas trig Trig clk Manual H M S External i Lvl above 13 58 40 1 Trig par BiRWGS BIBRWGS or seconds Modify the value by using the INC and DEC key on the right side of the display or key in a numeric value followed by pressing ENTER When the required time is set press ENTER twice for leaving the menus For making a measurement press the START key A Wait indicator will be shown in the display instead of the Run indica tor When the displayed time of the day as indicat ed by the clock in the instrument coincides with the triggering time a measurement will be automatically started If you want to interrupt a waiting for trigger opera tion press the STOP key If you set the repeat measurement store function Press SETUP gt 1 gt 1 the instrument will start a new measurement after the first is finished and wait for the trigger condition to be satisfied again This will occur at the same clock the following day In thi
133. er condition to be satisfied again If you want to interrupt a waiting for trigger opera tion press the STOP key Setting the level for the threshold trigge Trig LvlA Threshld 62 6 db Freq Netw Z netw BIBRWGS 79 80 Chapter 17 Sound recording Recording the sound The Nor140 instrument allows storing the sound signal itself obtained by the microphone if the appropriate option 8 is installed The most common application is for identification purposes by listen ing to the sound signal Dependent on the selected quality of the selected storing format the signal may also be used for further analysis The recording quality is available in several flavours serving slightly different purposes The main disadvan tage for using an unnecessary high quality is large files which consumes a large part of the storing medium and the need for a longer time for handling Formats Three different word lengths 8 16 24 bit and two sampling frequencies 12 kHz and 48 kHz give in total 6 different formats for the recorded sound A sampling frequency of 48 kHz is equal to the native sampling requency for the instrument and corresponds to the ull frequency range for the instrument about 23 KHz When combined with 24 bit resolution the format re flects the basic accuracy of the instrument and should be used if further processing of the signal is request ed When the sampling frequency is set to 12
134. er level 24dB 24dB 24dB 24dB 24dB Ref level test 94dB 114dB 114dB 114dB 114dB The primary indicator range for compliance with IEC 60651 type 1 is 24 dB to 117 dB For compliance with IEC 60804 type 1 the linearity range is 24 to 137 dB and the pulse range 24 dB to 140 dB respectively Total range for measurement of C weighted levels The linear operating range is identical to the total range Frequency 31 5Hz 1kHz 4kHz 8kHz 12 5 kHz Upper level 134dB 137dB 136dB 134dB 131 dB Lower level 30dB 30dB 30dB 30dB 30dB Ref level test 114 dB 114dB 114dB 114dB 114dB Total range for measurement of Z weighted levels The linear operating range is identical to the total range Frequency 31 5Hz 1kHz 4kHz 8kHz 12 5 kHz Upper level 137dB 137dB 137dB 137dB 137 dB Lower level 40dB 40dB 40dB 40dB 40dB Ref level test 114dB 114dB 114dB 114dB 114dB 155 156 Chapter 27 Technical Specifications Measurement range for C weighted peak levels Frequency 31 5Hz 1kHz 4kHz 8kHz 12 5 kHz Upper level 137dB 140dB 139dB 137dB 134dB Lower level 45dB 45dB 45dB 45dB 45dB Ref level test 114dB 114dB 114dB 114dB 114dB Power supply Battery 4 cells IEC LR6 AA sized Alkaline bat teries are recommended e g Duracell Ultra M3 AA sized NiCd or NiMH rechargeable bat teries may be used but must be charged outside the instrument Battery voltage and time on bat tery since last change of batteries are indicated Typical battery life time Duracell U
135. erberation mode of operation and the result stored for later processing MODE 2 Rev Alternatively the measurement may be started from the calculation menu when the result is required for the calculation Calculating the Survey result Select the building acoustic mode and press 2 for Impact Enter the value for the room volume V and press ENTER or move the field cursor to C and press ENTER for a calculator The calculator allows you to enter the length width and height of the room in order to calculate the volume The field cursor automatically moves between the fields as values are entered If you want to adjust any previously entered value use the arrow keys to move the field cursor to the wanted parameter Norsonic Nor140 Instruction Manual The next set of values to be entered is the sound levels in the receiver room L for each octave band Re call a measurement by using the RECALL key or press START for starting a measurement lf measured the values are automatically stored The sound level me ter should be moved as specified in the measurement standard to obtain the spatial average The acoustic losses of the receiving room used in the calculation may be obtained by measurement of the reverberation time by recalling measured values or by estimation The instrument must be equipped with the option for reverberation measurement in order to allow the measurement option to be used If the op tional noise g
136. erence box microphones for floor standing ap standing appliances placed pliances placed against a wall in a corner 3 Microphone position Sound power acoustic environment requirements A test area outdoors or an ordinary room will provide a suitable environment if the requirements given in the Annex A of the ISO 3746 and briefly outlined here are satisfied Reflecting objects other than reflective plane s shall be removed to the extent possible from the vicinity of the machine under test A test site shall ideally provide a measurement surface which lies a inside a sound field that is essentially undis turbed by reflections from nearby objects and the room boundaries and When measuring in accordance with the ISO 3746 the environmental correction factor K is obtained from this graph by entering the abscissa with the appropriate value of A S NV wo A aA QO N O O 50 100 300 A S Norsonic Nor140 Instruction Manual b outside the near field of the sound source un der test For the purpose of the survey method the method described here the measurement surface is consid ered to lie outside the near field if the measurement distance from the source under test is equal to or greater than 0 15m a Description of Room 0 05 Nearly empty room smooth hard walls made con crete brick plaster or tile 0 1 Partly empty room room with smooth walls 0 15 Roo
137. erman speaking markets will have tables not containing the lose values E and T 5 Displaying the result table using the other spectral weighting function Spectral weighting network indicator 0 05 A 0 05C Leq 37 9 Leq 56 0 F Max 39 5 F Max 582 FMin 373 FMin 53 2 LE 449 P9 LE 630 Peak 53 5 Peak 66 5 ILeq 464 ILeq 58 5 F Tmx5 39 5 1 S FTmx5 582 FSPL 5 NEW psp The actual spectral weighting function used in the table depends on the setting active before the TBL key was pressed At any rate press NETW to toggle between primary and secondary weighting function Statistics displaying the percentiles Instruments equipped with the optional extension 4 statistics will measure the statistics every time This cannot be switched off The sampling for the statistical calculations is made with F time constant and the class width is 0 2 dB over the entire 130 dB dynamic range always You may think that storing all these data will require a huge memory and you re absolutely right Therefore we refrain from that we store just eight percentiles instead Seven of them are fixed and one is user editable Your user editable percentile can be set to anything in the range 0 1 99 9 both extremes included The procedure is explained next page Norsonic Nor140 Instruction Manual Data measured not recalled may be subject to changes in th
138. es displayed in linear units will vary over more than six decades By changing the sensitivity of the instrument calibration the display range may need to cover nearly twelve decades A floating point format for the linear indicated value is therefore necessary A letter following the numeric value is used for indicating the power of ten exponent The graphical display is left unchanged when engineering units are selected 060825 0011S 120 16 125 1k 8k AZ 40 0 17 Leq 38 6m 315Hz IBERWGS The following letters are used f 1075 femto p 107 pico n 10 nano V 10 8 micro m 107 milli k 10 kilo M 108 mega G 10 giga T 10 terra An underscore is used if no other postfix charac ters apply The following examples may illustrate the principle 189m 189x10 lt gt 0 189 78 3u e 78 3x10 6 gt 0 0000783 Norsonic Nor140 Instruction Manual Relation between dB and EU The logarithmic dB scale is a scale relative to a com mon reference value In the Nor140 instrument the ref erence value is always 2x10 corresponding to the common reference value for sound pressure levels 20 uPa A linear quantity X will therefore correspond to a level x de e X 2x10 where This implies that 1 EU corresponds to 93 979 dB or as usually stated 94 dB Calibration The sensitivity is always expressed as a logarithmic sensitive in dB relative to 1 volt EU Even if enginee
139. es not included Complete building acoustic mode in accordance with ISO 10052 and ISO 140 series and sound insulation indexes calculated according to ISO 717 1 and ISO 7171 2 require options 1 3 9 and 10 Swept Sine remote measurement mode require option 11 and Nor1028 NorBuild software on PC Speech Transmission Index mode Calculates the STIPA value according to IEC60268 16 Incl CD with excitation signal Nor1034 require option 1 FFT mode Survey sound power mode for LwA measurements according to ISO 3746 Trigger for global measurement based on clock threshold and external signal Extended measurement range with the normal microphone 150 dB peak including self noise compensation Extended noise monitoring features such as repeatable read out bil Taking a closer look at the instrument You may have to assemble the instrument the first time you use it Be sure to take utmost care when mounting the microphone cartridge onto the preamplifier Always keep the preamplifier disconnected when ever you are screwing the cartridge onto the preamp lifier and screw only finger tight The instrument is powered from four AA size bat teries which are inserted as shown below If you use rechargeable batteries these will not be recharged if you connect the Nor140 to an external power supply Example of batteries inserted correctly Switching ON OFF The instrument is toggled ON OFF by pressing the right lower key Note
140. es table In the percentiles table press the I key the end lef key to enable this Once the percentile field is shown inverted with white text on black background the text can be edited using the NUMERICAL KEYPAD or INC and DEC If you use the NUMERICAL KEYPAD you must press ENTER to confirm that you have keyed in the new percentile To terminate the editing process press the gt I end right key The corresponding percentile value will now be displayed given that the measurement duration was long enough to provide a sufficient number of samples The user defined setting applies to every network and frequency band They cannot have individual settings 35 36 Chapter 5 Frequency analysis Data measured not recalled may be subject to changes in the user defined percentile This means you may change the percentile as many times as you want For stored and later recalled data any changing of the user editable percentile is no longer possible How to set the user editable percentile is described in the side bar on the previous page Storing the acquired data The Nor140 has a large non volatile memory to hold the measurements Thus memory needs no battery power for retaining the dara The same holds for the optional SD card The memory structure resembles the memory structure of a personal computer in the sense that both use folders and files The structure of the Nor140 is very simple the
141. et are available 8 Chapter 1 Introducing the Nor140 Check which extensions are installed Unless you are certain about the extensions installed in your Nor140 we recommend that you spend a little time looking into the matter Note The codes are unique for each instrument and will not work in other instruments Do not change these codes as you will then loose the optional extensions installed and activated The extension menu Press SETUP gt 1 gt 0 although you won t find the O listed as an option in the Instrument setup menu The menu contains a unique ID code which identi fies the very individual instrument whose menu you re looking at In addition the menu contains three codes These codes enable the extensions activated for this instrument The codes take the ld number into account and are valid for this individual instrument only e To leave the menu without restarting press EXIT e To leave the menu press ENTER Note that the in strument will restart as a consequence of this Workload Dependent of the options installed the Nor140 instru ment has the ability to measure a large number of dif ferent functions in addition to sound recording The selection of functions is made by the user through the set up menu system A large number of selected func tions combined with very short measurement periods and sound recording may give a workload in excess of the capacity for the signal processor If this appears
142. etup Wizard Set up or addto a The COM port number can be found here h Micg i y Communications Port COM1 J ECP Printer Port LPT1 A USB Serial Port SLM OM7 SM Processors 9 Sound video and game controllers System devices Universal Serial Bus controllers Virtual Instrument Nor1036 Installation procedure Load the application CD and select install Virtual in strument Follow the procedure given by the installa tion program Using the NorXfer Nor1020 If you store the data on a SD card you may transfer the data by plugging the card into a suitable card reader We still recommend using the NorXfer soft ware for transferring the data to a suitable format This program also allows importing the data into en Excel workbook or programs for more extensive analysis like NorReview Nor1026 Deleting the data on the SD card may be either done in the instrument or by the PC If the entire card shall be cleared we recommend formatting the card on the instrument Deleting a large number of files and directories may take a considerable amount of time Deleting single files may also in the long run end up in a less effective file structure The instrument can also be controlled from remote For a complete list of remote control commands con tact your local representative or the factory See the information on the CD for how to operate NorXfer NTE teres sen Tyee 5 ux Norsonic Nor140 In
143. evel ao n tee e E ds 88 Extension for reverberation measurement oooocconoccconocnncnonnnnonnnnnonnnnnnnnnnnnonnnonnnonnnnnnonnnnnnononnnonnnnnnnnns 89 Norsonic Nor140 xi Instruction Manual Chapter 20 Compensationand correction A EIU A Use ot WINS Miri e aine n Pe oc da ae Gea ene Random incidence and diffuse sound fields sss 91 Meas rement or low sourid I amp vels ode p ii PT eld dte d udin ca 91 Me amp asuririg tlieself nolse noi eh e DSL e RU RI HEURE dadas 91 Measurementor high Sound levels erra nce eta temet at ede DER Idest 92 Chapter 21 Reverberation time measurements eeeeeeeeeeeeeee esee nennen nnne rnnt nnn 94 Whatis reverberation time uic ee aO I EV ED e NR 94 Calculating the reverberation time esssssssseeeeeneeneneeeemeeemeeeee nennen 95 Measurement with MOISES EXCMO iiu eet re E EHE coi 95 Measurement with impulse excitation a anaana a a eene eme mener 95 Irplementation nmiNOE A0 cit rrt a Mr athe Gra NE E Uber Rated 97 Excitatiomslgrials 3 S a et aa 97 Minimum reverberatiofitime poSSIDIE s ie tec Ret e RUE re erben 98 Measuring according to the integrated impulse response method ssssss 98 Measuring according to interrupted noise method sssssss e 99 Chapter 22 Sound POWGLF iia 102 About sound power measurements o iere Eee dee t A ee edd pe ecran 102 Rectangular parallelepiped nir 1 tut et
144. eys to move the cursor along the time axis 3 Use the Mi and the Dl keys to move the cursor one screenwidth along the time axis in either direction To see the spectrum of another moment in time 1 Make sure the instrument is in profile mode and that the spectrum is displayed a A displayed in the up per left corner of the display If not press the ZA key to enter profile mode and the fot key to enter the frequency domain Use the and the W keys repeatedly if needed to reach the moment in time required By following line 1 the time profile the level vs time of one specific fre quency band is obtained To display the time profile of another frequency band e g line 2 you must use the vertical cursor keys At any moment in time you may display the spectrum use the fot key This could correspond to line 3 While you display the spectrum at a given moment in time you may use the vertical cursor keys to display the spectrum of another moment in time e g line 4 In other words the vertical cursor keys are used to move in the other domain than the one displayed to move in time when displaying the spectrum and to move in fre quency when displaying a time profile To see the level vs time the profile graph of an other frequency band 1 Make sure the display shows a time profile level vs time Use the fot key if needed 2 Use the and the W keys repeatedly if needed to move to another
145. fer function at frequency F may be calculated directly from the value of the reverbera tion time T and the effective signal to noise ratio S N in dB A simplified formula not taking the effects of masking and the threshold of hearing into considera tion indicated the following relationship 1 1 m F A 1 2nF y T3105 9t As seen from this formula a limited signal to noise ratio reduces the modulation transfer function for all frequencies A long reverberation time reduces the modulation most for the highest modulation frequen cies The STl value is a weighted average of the differ ent modulation indexes The last revision of the method IEC standard also considers masking effects and the absolute threshold of hearing RASTI and STIPA In order to simplify the direct measurement the RASTI method Room Acoustic Speech Transmission Index was developed at TNO in 1979 Different instruments were developed for the measurement according to this standard A typical measurement time was 10 to 15 seconds The RASTI method only considers two oc tave bands 500 Hz and 2 kHz Due to the simplicity in use the RASTI instruments were used also for applications beyond the main de sign goal room acoustics The RASTI value is often used for assessing the quality of public address sys tems but comparisons with subjective measurements have shown that the deterioration of speech intelligibil ity is not handled correctly if th
146. g the sound level meter to indicate 113 8 dB diffuse cor rection off If other types of calibrators or electrostatic actua tors are used for the calibration we recommend ad justing the sound level meter to indicate the following levels referred to the sound pressure acting on the dia phragm of the microphone diffuse correction off 125 Hz 250Hz 1kHz 4kHz 8kHz 0 0dB O 0dB 0 2 dB 0 8 dB 2 8 dB Freq Level Measurement duration and resolution The total time period for a measurement global pe riod designated X may be set from 1 second up to 200 hours less 1 second with 1 second resolution The global period may be subdivided in shorter periods designated time resolution A from 1 second up to the global period As an option the time resolution may be set in an additional range from 50 millisecond and upwards to 1 second in steps of 25 millisecond Timing accuracy The measurement duration and resolution is locked to the extremely accurate internal clock Within the temperature range O C to 40 C the maximum drift is 3 ppm corresponding to an accuracy of better than 10 seconds per month Aging for 10 years may increase the figure with additional 13 seconds per month Norsonic Nor140 User Guide Measurement range Total range for measurement of A weighted levels The linear operating range is identical to the total range Frequency 31 5Hz 1kHz 4kHz 8kHz 12 5 kHz Upper level 98dB 137dB 138dB 136dB 133 dB Low
147. g are available for all functions including the Leeak The Z weighting as specified in IEC 61672 1 replac es Lin or Flat as these have not been properly defined by any standard As an optional extension the instrument functional ity can be expanded to include the ability to measure with all three time constants F S I applied simultane ously The main features an overview Level vs time The electronic level recorder concept is available in two versions basic and enhanced While the basic version logs the equivalent level the maximum level and the peak level the enhanced ver sion is capable of logging any combination of func tions available with the Nor140 In addition it allows Source coding Another difference important for some applications is that while the basic version has a time resolution ranging from 1 second and upwards the enhanced version has a time resolution from 50 ms and upwards in 25 ms steps Above 1 second the time resolution is available in 1 second steps for both versions Frequency analysis When fitted with the frequency analysis extensions the Nor140 can make real time frequency analysis in octaves or third octaves The functions measured are the equivalent level the maximum level and the minimum level The frequency range is 0 4 Hz to 20 kHz and thus covers both the audio and the vibration range Statistics The optional extension 4 adds statistical distribution to the Nor140 functiona
148. g the instrument Input impedance 10 kohm connected to the positive supply 3 3 volt Any open input will therefore be in the high state Digital outputs The digital output signals are 3 3 V CMOS signals Maximum output impedance 100 ohm During pow er up the output lines will be low or in ahigh imped ance state 100 kohm to ground Digital output control lines The Nor140 instrument has 4 digital output lines which all can be used to control external devices or functions based on the internal status of the instrument The dig ital output lines are named DO 1 to DO 4 see the pin configuration of the general I O sockets for connection details The function of each digital output line is selected by the user through the Digital I O menu found by using the key sequence SETUP 1 Instrument menu 2 10 Print 1 DiglO The following functions are available for each of the four output lines OFF No function on this output line output level continuously low 0 USER Output level high 1 or low 0 is controlled via remote operation of the Nor140 instrument see remote command list for details CAL Output level is high 1 as long as the instru ment is performing the calibration procedure either manually through the Calibration menu or remotely from an external software GO Output level is high 1 when the Go NoGo quality control comparison test of the Refer ence Spectra is successfully fulfilled see
149. g the measurement The measurement may be stopped before the selected number of periods is reached by pressing STOP The duration of each single FFT period is 0 685 s The FFT mode is selected in the mode menu MODE 1 Normal Rev Power Buildac STIPA FFT Q ue Wh DURWGS 144 Chapter 25 FFT measurement mode During and after a measurement the result is dis played as shown on the figure The upper and lower values of the displayed frequency axis are shown just below the diagram The frequency range may be zoomed or compressed The compression factor are adjusted in a power of 2 sequence by cursors keys 4 Compress and W Zoom respectively 1x 2x 4X etc The cursors are moved along the frequency axis by the cursor keys d and p If the cursor is in the left or right extreme position the spectrum will scroll about 1 3 of the displayed frequency range The cursor keys M and Dl moves the cursor to the extreme left hand or right hand position respectively A further operation of these keys will scroll the display along the frequency axis The displayed level range may be scrolled by us ing the INC and DEC buttons as in normal mode of operation Setting the measurement duration Meas dur Duration 000 00 06 Resolution 685 ms NA ET N 0 Mx 340 BISRWG Calibration The instrument has to be calibrated in the normal mode of operation The readout may be in
150. g to 10dB to 137dB with a mi crophone sensitivity of 50mV Pa The maximum peak value 10V corresponds to 140 dB With the optional extension permitting extended measurement range peak values up to 150dB may be measured Microphone input socket Pin Function 1 Microphone system check 2 GND signal reference 3 Polarisation voltage selectable 01V 200 1V or adjustable 70 to 74V short circuit current lt 1mA impedance 2 MQ 4 Signal input Input impedance min 0 6 MQ max 250 pF When ICP is selected in the setup a con stant current of 4 mA is suppled 25 volt source 5 15 1V preamplifier supply voltage max 3 mA Connected to pin 6 Not connected 7 15 1V preamp supply voltage max 3 mA Housing is GND instrument casing o Highpass filter frequency response 0 zt OFF FTEHT T TTEHIE T TTTETI 20 E eh n tr bh bn 666r nm 1444414 00 c amp ice SNA 40 LH Tee ON i 4 0 01 0 1 1 10 100 1000 Frequency Hz Highpass filter The input section is equipped with an analogue high pass filter to reduce noise from wind or other sources with frequencies below the frequency range for meas urements The filter is switched on if the limited fre quency range is selected gt 6 3HZ Filter type 3rd order HP filter 3dB at 3 4Hz Butterworth response Analogue to digital conversion The analogue input signal is converted to a digital signal by a multirange sigma de
151. gh 8 0kHz 18 4 the functions measured 10 0kHz 19 0 12 5kHz 19 0 16 0kHz 17 3 20 0kHz 21 9 A netw E C netw s Table 2 dB A020419 0004S 0 2 7 500 A network F SPL 48 6 Use WA keys to move Leq 484 up and down in frequen cy incl spectral weight F Max 49 3 ing networks anda 4 F Min 48 6 keys to move to another S Min 54 1 moment in time and FUNC to scroll through the functions measured 51 52 Chapter 9 Multispectrum measurements Global mode Profile mode 1 TBL 0 05 CF D L 03 1 TBL L 1 0 L 5 0 57 5 lt q L10 0 57 1 L50 0 56 0 L90 0 54 8 L95 0 54 5 53 9 od aera 2 fot Multispectrum mode Global frequency mode 0 08 4e Leq 4 eee FMax 47 2 iPMin 17 o A 5 LE 49 5 1 TBL j F 19 3 F Min 48 6 S Min 54 1 Both tables are accessible during measurement you can even start a measurement from within any of the tables All functions available for a profile measure ment apply even here If your instrument supports the use of markers they may be used in the usual way Pause and global back erasure also works as usual For a discussion of these features turn to Basic time profile measurements Enhanced time profile measure ments and Adding markers
152. gularly shaped room with furniture irregularly shaped machinery or industrial room 0 25 Room with upholstered furniture machinery or in dustrial room with small amount of acoustical ma terial 0 35 Room with acoustical material om both ceilings and walls 0 5 Room with large amounts of acoustical material on 0 ceiling and wall 0 5 1 5 10 50 100 300 A S Calculating the A The value of the mean acoustic absorption coefficient a is estimated by using the above table or by means of reverberation time measurements The value of A is then given in m by Az a xS in which S is the total area of the surface of the test room walls ceiling and floor in m Calculating the S n Hemisphere S 2nr Parallelepiped S 2 4 ab bc ca l a 5d o ll NBC Y o ll o L are the dimensions of the rectangular refer ence parallelepiped 113 114 Chapter 22 Sound power Background noise A background noise measurement is required to have the instrument calculate the background noise cor rection K for you On pressing the FUNC key the background noise measurement control display is dis played This test follows the exactly the same proce dures as the sound power measurements However the background noise level will in most situations vary little from one microphone position to another it will therefore normally be enough to meas ure the backg
153. h this option The STIPA option requires the following additional option to be installed in the sound level meter Option 1 1 1 octave real time filters in the frequen cy range 8 16 000Hz CD for excitation The CD type Nor1034 included with the STIPA option contains two tracks Track 1 and 2 e Track 1 1 kHz sinusoidal signal Duration 2 minutes Track 2 STIPA excitation signal male speech Duration 70 minutes Both signals have the same A weighted level Track 1 may therefore be used for test or calibration purposes although the noise signal is recommended The STIPA excitation signal consists of bands of random noise each modulated with two frequencies See IEC 60268 16 for further details Note that if a loudspeaker is used for excitation the loudspeaker s frequency response may change the spectrum of the excitation The sound level meter may be used to verify or adjust the spectrum For an excitation signal with A weighted level Lx the various octave bands should have the levels shown in the table on the right CD with Excel sheet The CD contains two Excel work books to be used with a PC STIPA Calc Allows correction of the STIPA result for a virtual background noise e STI Calc A sheet for estimating the STI value based on the speech level background noise level and the reverberation time Norsonic Nor140 135 Instruction Manual Octave band levels for male speech signal of A weighted leve
154. he CUR DIR i e the current folder or di rectory all data in the entire memory or to RESET the entire memory The option cancel is also includ ed to avoid unintended erasures If so use EXIT to leave the menu is selected reset is replaced by FORMAT Formatting the SD card will be faster and the recommended method for clearing all data on the card You cannot delete the file that you are displaying Therefore in order to clear this file press EXIT before you enter the CLEAR menu 63 64 Chapter 12 Automatic storing of data and noise monitoring Automatic storing of data and noise monitoring Due to its large memory and the high dynamic range the Nor140 is well suited for noise monitoring applica tions Some installations semi permanent or perma nent are based on tight computer control while oth ers leave more of the job to the measuring instrument itself The Nor140 can be used with success in both types of systems The Norsonic environmental solutions contain a complete range of equipment and accessories for environmental noise measurements and monitoring all the way from outdoor microphone units via enclo sures and transmission cables to controlling and post processing software A detailed presentation is avail able at www norsonic com Automated storage of measured data The instrument can be set up to measure for a prede fined period in time and then store the measured data Once the data hav
155. he internal memory is of the flash type retaining the informa tion without battery supply Approximately 25 Mbyte is available for the data storage Environmental conditions Reference conditions The reference conditions for the instrument are as specified by IEC 61672 1 Temperature 23 C Humidity 50 RH Atmospheric pressure 101 325 kPa Environmental condition for operation Temperature 10 C to 50 C Humidity 5 to 90 RH dewpoint less than 40 C Atmospheric pressure 85 kPa to 108 kPa Environmental condition for storage Temperature 30 C to 60 C Humidity 5 to 90 RH dewpoint less than 40 C Atmospheric pressure 50 kPa to 108 kPa Warm up time The warm up time for the main instrument without pre amplifier microphone is very short and the instrument obtains the final accuracy as soon as the self test is made Used with a preamplifier and microphone this time is prolonged due to the charging of the micro phone with the polarisation voltage Normal sensitivity is reached within one minute Before a recalibration is attempted at least three minutes for warm up is rec ommended Sensitivity for vibration If the instrument is used under strong vibrational con ditions it is recommended to use an extension cable between the preamplifier and the instrument body The vibration will mainly affect the microphone which is most sensitive if the vibration is applied perpendicu lar to the diaphragm Ty
156. he light switches off automatically 2 minutes after the last operation of any key The bar graph display covers 80 dB which may be scrolled in 10 dB steps to cover the total range Keyboard The keyboard is of silicon rubber type Random response correction 14307 1 10 Frequency Hz 10 100 140 Correction a0 05 12 55 111025 Random 18 35 16 Windscr ON 1 Preamp ON FSPL 10 S noise ON 7 0 1 Corr par C End A 37 2 J RWGS RWGS Adjustment of indicated levels Random response The instrument is equipped with a microphone with flat free field response and satisfies the class 1 requirements in IEC 61672 1 to free field re sponse By selecting the random response correction network included the instrument will satisfy the class 1 requirements in IEC 61672 1 to random response as well as ANSI S1 4 1997 type 1 The nominal correction to obtain flat random response is shown in the figure above Activating random response correction e Press SETUP gt 1 Instr gt 6 Correct to gain access to the Corrections menu Navigate in the menu as usual and activate the correction parameter Random by means of the INC and DEC keys Do the same to deactivate Random response correction activated is indicated by an R in the lower line of the display Norsonic Nor140 User Guide Windscreen The instrument may be used with windscreen Nor1451 The windscreen c
157. he menu as usual The A weighted value and the C or Z weighted value will appear as extra bar graphs to the right of the spec trum in the display Activating the frequency mode In order to enable frequency analysis the frequency mode must be activated Activating frequency mode e Press SETUP gt 4 Freq mod to gain access to the frequency mode menu Navigate in the menu as usual Set the bandwidth as required e Toggle the mode On or Off by using INC or DEC buttons e Select bandwidth by using INC or DEC buttons 1 1w Octaveband 0 5 16 000 Hz 1 1 Octaveband 8 16 000 Hz 1 3w 1 3 octaveband 0 4 20 000 Hz 1 3 1 3 octaveband 6 3 20 000 Hz Going to measure very high levels As an optional extension the Nor140 is able to measure very high sound pressure levels without changing the microphone cartridge see High levels in the Technical specifications for details Norsonic Nor140 29 Instruction Manual Menu for activation of the frequency mode Press SETUP gt 1 gt 4 Freq mode _ to produce this menu Mode Bandw 1 3 Ref spectra Upper Off Lower Off QC Off 1 Ref par WS F As long as the frequency mode has been AVE activated frequency analysis will be made E during every measurement This means that the instrument will combine a traditional sound level meter measurement and a real time fre quency analysis in octaves or third octaves Whether the instrument is setto
158. he value directly Step size is 25 ms If you key in a value between valid settings the value will be put to the nearest valid setting M The effect of pressing stop before Ay resuming If you terminate an ongoing meas E urement prematurely by pressing the STOP key and later resume the measurement by pressing PAUSE CONT an S marker will be added to the period within which the pause cont key was pressed i e we mark out the first period after resumption Measuring in enhanced mode The enhanced time profile mode is similar to the basic time mode and should thus be regarded as an add on to the instrument s basic functionality This means that the features available while measuring described in the chapters Simple sound measurements and Frequency analysis apply even here Displaying the functions measured To see the different functions measured just use the FUNC key as usual Presenting the L t as a table Numerical presentation of the acquired data works even here Press TBL while in A profile mode to produce the table This can be done during as well as after a measurement Use W keys to move the cursor up and down but only after the measurement have ended Norsonic Nor140 Instruction Manual 45 46 Chapter 8 Adding markers to a measurement Adding markers to a measurement Have you ever made a measurement where you later found out that you desperately need to identify the cause of the level
159. hich are not global can be adjusted in one mode of operation for the instrument without af fecting the value of the same parameters in another mode of operation If you close a mode and return to it later the value last used for the parameters will be automatically loaded To store a measurement setup e Set up the instrument as required and press STORE without making a measurement Setups are stored in a separate folder called SETUP If you have made a measurement and the instrument presents a result you will store the result and not be able to store the setup if you press the STORE key You may clear the values and return to the Ready mode by pressing the EXIT key 59 60 Chapter 11 Memory handling Standard set up Recall INT SETUP 0006L 0007R 060823 0008R 060824 0009R 060825 0010R 0011P 00128 00135 WS All settings are stored but upon recall of a setup all settings affecting the hardware is not read back into the instrument Hardware settings such as baud rate preamplifier gain and the calibration sensitivity are examples of settings not read back However all settings of functions and parameters used in the measurements are read back Storing a measurement Once a measurement has been made it can be stored in the non volatile memory for future use either internal or the SD card To store the data e Press the STORE RECORD key after a measure ment The data will now be stored
160. how the level versus fre quency display Time constant will be F The cursor will be positioned for indication of the A weighted level Making a measurement Start a measurement by pressing the START button The measurement lasts for 13 seconds During the measurement the level versus frequency display will be shown together with an indicator of an ongoing running measurement After the measurement is ended the main STI display will be shown after a short calculation period For the first measurement after the STl mode is selected the Noise correction will be selected off and the cursor will be placed above the Off field The measured result will be indicated as a STI value together with an assessment of the intelligibility The STl value and the assessment are according to the STIPA procedure in IEC 60268 16 2003 05 for male Display during measurement of STIPA Main result display 120 STI 0 81 Excellent CIS 0 91 LA 69 3 16 125 lk 8k AC NCorr 40 0 06 AF SPL 79 7 RIBRWG BigRWG 137 138 Chapter 24 Speech Intelligibility by STIPA Display of speech level octave band spectrum 0 13 A oct Lea 125Hz 75 250Hz 73 500Hz 66 1 0kHz 62 2 0k Hz 5 4 0kHz 8 0kHz 50 16 0kHz 31 A netw 69 BIBRWG Two modulation indices are measured for each octave band A oct m e 6360 Modulation 5 0 74 index for 500 Hz US ps Octave band i e 0 92 modulat
161. hus giv ing you the time profile for the measurement The MAX and the PEAK levels are also recorded per period so that all three functions will yield a value for every period When you are going to make a measurement the maximum number of periods at your disposal will de pend entirely on the amount of free memory available Given the large memory of the Nor140 the period duration will for all practical cases be determined by your need for time resolution Provide details maintain overview The level vs time feature is the tool you need for detailed analysis of the time profile However a measurement failing to provide an overview of the entire analysis cannot be accepted Norsonic Nor140 Instruction Manual So we added a global analysis to all time profile measurements It just runs in the background and makes little fuss about its presence Switching between global and profile is easy a ded icated key on the front panel the ZA key lets you toggle between the two The X pronounced sigma often used for a sum denotes the global analysis while the A pronounced delta denotes the time profile Consequently when you have set up for a time pro file measurement by defining the total duration and the time resolution you have in fact prepared the instru ment for two parallel measurements the global and the profile Absolute vs relative time The instrument contain a calendar and an accurate clock and all
162. ic AS Gunnersbr tan 2 N 3408 Tranby Norway declare under our sole responsibility that the product Sound Level Meter Real Time Analyser Nor140 to which this declaration relates is in conformity with the following standards or other normative documents Standards 1EC61672 1 Class 1 ANSI S 1 4 1983 type 1 IEC 60651 Type 1 ANSI S 1 43 1997 class 1 IEC 60804 Type 1 ANSI S1 11 2004 class1 IEC 61260 class 1 EN 61010 1 February 2001 following the provisions of the EMC Directi This product has been manufactured in compliance with the provisions of the relevant internal Norsonic production standards All our products are tested individually before they leave the factory Calibrated equipment traceable to national and international standards has been used to carry out these tests During the RF emission test the following was connected USB cable 1m mains adapter NOR 340 microphone preamplifier NOR1209 and microphone NOR1225 Setup Measurement duration 1h Frequency mode parallel 1 1 octave 2nd network Z During the RF immunity test the following was connected USB cable 1m microphone preamplifier NOR1209 and microphone NOR1225 Setup Frequency mode parallel 1 1 octave 2nd network Z Orientation Laying face up on the table and the microphone was pointing towards the antenna During the AC power frequency field test the following was connected microphone preamplifier NOR1209 and microphone NOR1225 Setup Frequency mod
163. ime to time After a time with normal use where files are stored and deleted the file structure may be fragmented which lower the speed for transfer of data The card may be formatted by the following operation Mount the card in the card slot on the left side of the instrument Press the DEL key The upper line in the display should read Clear SDC if not press INC or DEC e Press cursor left gt ENTER e Scroll down to FORMAT and press ENTER e Confirm the FORMAT selection and press ENTER Wait until the format operation has been completed Select the device for storing You may select either the internal memory or the op tional SD card as the location for storing data You have one selection for measurement setups and one for the result of the measurements The selection is done in the instrument menu e Press SETUP gt 1 Instrum gt 1 Storing e Use the cursor key and move to the field for setup Use the INC or DEC key to select the wanted place for storing the setup e Use the cursor key and move to the field for Result Use the INC or DEC key to select the wanted place for storing the result of measurement e Press ENTER repetitively for returning from the menu system Storing a measurement setup Measurement setups can be stored for future use This can be handy feature when the instrument is used by several people or for many different tasks This measurement has been stored as file No 7
164. ing machine near the middle of the room is sufficient for measurements according to ISO 10052 For other measurements more positions are required Norsonic recommend the tapping machine Nor211A or Nor277 Measurement of sound level As stated in the standards the spatial average of the sound level in the receiving room is required For sur vey measurements according to ISO 10052 this may be achieved by measuring the level while moving the sound level meter microphone around in a figure of eight trajectory Recommended measuring time is 30 seconds For the engineering method according to ISO 140 7 point by point measurements has to be applied and the instrument will calculate the averaged level The level may be measured in the normal mode of operation and the results stored for later processing Alternatively the measurement may be started from the calculation menu when the result is required for the calculation Press SETUP to enter the menu for setting the measurement time Reverberation time For a survey measurement according to ISO 10052 the corrections for the acoustic absorption may either be based on measurement of the reverberation time or based on estimation based on room type type of surface and furniture Both methods are implemented For measurements according to the ISO 140 series of standards the reverberation time has to be measured If a measurement is required the reverberation may be measured in the rev
165. ing the sound eeeeseeeeeeseeee esee e eene nennen nennt nns nn nannten nane nnn 80 SO 80 RECOrAINS DAN 3 322 5 v act ese e oc mida Airs T A 80 Recording duration oe ici tts ardet 81 Makingia ECO Mii nisi k ete c e tora nr ei d a A ea aa eae ce 81 Setup toradTecordirngss ec cc enc ie ces etre Du ou eite Le e e ee 81 Setup how to start a recording ua ce e ete np e epp odes 82 Manualitfggetsc s acr et ai cer EH o eU DE epp ERU ir a tue mtetqeen ludo seed iced oct 82 External triQGer iene see eR et 82 EevelaboVe tFlggetz c eoe n Ne ees E a i etae te os 82 ESO ii eem pr e ou tate cda bed e pare ec pede heed 83 Inserta r rerence tone as a Tecordlhigzusus o E rere OR OL HU order 83 Reference Spectrum General d d p en baee ee eq d eda eq RR Dude Activating the ReferenceSpectrum features ssssssssssssssseeeeeeeemeen 84 Selecting the Reference Spectra sss 84 Usirig a previouslymeasured speClIulTi je esc itc eror o Oe d co D Oo e HE tre 85 Entering a new Reference Spectrum manually sss 85 Editing a selectedReference Spectrum ssssssssssssssseseeeeeeee eere 86 A pre weighted Reference Spectrum sss enne 86 Go NoGo Quality Control feature ssssssssssssseeeeeenee eren 86 Digital GUtp t llries 3 3 x A nectar dne A ale ial Re aes 86 Noise Generaltor 5 nerna ciere iia 88 ier PERI 88 Selecting noise type and l
166. ion When the FFT option 14 is installed the instrument may make a narrow band frequency analysis of the in put signal and calculate the autospectrum The signal is sampled with a sampling frequency of 24 kHz and a Fast Fourier Transformation based on 2 16384 samples is performed This allows the signal to be ana lysed with a constant frequency resolution of 1 46 Hz The signal strength may be displayed in logarithmic dB or linear units engineering units EU How to select the FFT mode To put the instrument in FFT mode of operation press the key MODE and select 6 for FFT If you want to return to the normal mode of operation you have to press the key MODE again and select 1 for Normal Making a measurement A measurement in FFT mode may be started as a nor mal level measurement by pressing the START button If Option 16 extended trigger is installed the same trigger possibilities apply as in normal mode of opera Norsonic Nor140 Instruction Manual tion the measurement may be started at a certain time of the day or if the level goes above a certain level The level triggering is based on the normal weighting network or fractional octave band level The measurement duration may be set as time or as a number of single measurements used to obtain an averaged auto spectrum See figure overleaf NA indicates the number of single measurements in the averaged value The averaged result is continuously updated on the screen durin
167. is as before 7 minutes and 20 seconds The following periods are all shortened so the sum of the time for measurement and storing are kept within the limit of 15 minutes The instrument will start a new measurement period a cou ple of seconds after the following hour 09 00 09 15 09 30 09 45 10 00 10 15 etc We recommend limiting the use of the synchro fea ture for measurement periods which are either a multi ple of one hour or one hour divided by a whole number as the feature has been designed with this limitation in mind If you want to apply short measurement periods be low a few minutes we generally recommend using the level versus time feature as this gives no gap in the measured levels between the different periods M Keyboard lockout locking the keyboard to E prevent unauthorized operation You may lock gt the keyboard to prevent the instrument from being tampered with while it is left on its own On off is only locked if a measurement is running To lock the keyboard Press Iq P Pl dto lock the keyboard To unlock a locked keyboard Press d Dl P Id to unlock the keyboard Note that the instrument must show the sound level meter display for this to work in this display the cursor keys are not used 65 66 Chapter 12 Automatic storing of data and noise monitoring Setting the storage mode To set the storage mode e Press SETUP gt 1 Instr gt 1 Storing Use the cur sor keys located
168. is indicated by an R in the lower line of the display Norsonic Nor140 Instruction Manual N You may either set the sensitivity to the com AVE bined value for the microphone and the micro d v gt phone preamplifier or split the sensitivity in one for the microphone and one for the preamplifier See chapter 27 Technical specifications E level of the microphone cartridge dB relative to 1 volt pascal e g 50 mV Pa corresponds to 26 0 dB The instrument may also be set up to compensate for the attenuation taking place in the preamplifier which normally amounts to about 0 2 dB see Preamplifier attenuation in the Technical specifications for more on this r 4 N The dB value corresponds to the sensitivity N 17 18 Chapter 3 Calibration A of the measurement system along the signal line from microphone preamplifier until the display of the instrument 20 Microphone check For long term monitoring purposes it is often handy to be able to check the functionality without the use of an external calibrator The Nor140 has a build in Mic Check feature that allows this Pin 1 on the microphone input socket is able to supply a known voltage signal to the Norsonic Preamplifier Nor1209 see Chapter 26 for details By enabling this constant voltage signal the entire measurement chain including the microphone is tested and the display will show the corresponding measured value in dB Hence if this value is constan
169. it assign both 4 and P or S No it won t P and S have priority and they will be inserted instead of any other marker active by the time pause or stop is pressed So you ll never have more than one marker assigned to a profile period JuUucoL c0nm 35 Lr Marker 1 has been inserted Norsonic Nor140 47 Instruction Manual Marker overview M1 marker M2 marker M3 marker M4 marker toggle Stop Pause Sound record Signal overload Work overload too many functions selected The keys used to insert markers 5 48 Chapter 9 Multispectrum measurements Multispectrum measurements The combination of filters minimum option 1 and time profile mode minimum option 6 takes the instrument to greater sophistication by introducing multispectrum measurements This upgrade of time profile permits complete spec tra to be measured as a function of time not just broadband values albeit spectrally weighted You may then track a given frequency band as a function of time or inspect the spectrum at a given moment in time This is illustrated by the dotted lines in the below Fig Setting up for multispectrum Multispectrum measurements can be made based on basic as well as enhanced time profile extensions installed Units equipped with basic profile extension Units equipped with basic time profile extension and filters of course have a very simple setup procedure To set up for mu
170. itch between time elapsed since start of measurement relative time and date time of day absolute time use the ABS t key To display other functions measured Use the FUNC key For the German speaking markets these functions will include Ley and Tmaxs To adjust the display top scale e f the bar graph fails to match the level measured use the INC and DEC keys to alter the display top scale setting To switch between the spectral weighting functions Use the NETW key to switch between A weighted and C or Z weighted or the A weighted and the C A Z A weighted functions To produce the results in tabulated form Press TBL to produce a result table See Displaying the result tables for more on this N 7 MS Resuming an ended measurement Assume that you have set up the instrument to meas ure for 5 minutes and that you start the measurement After 5 minutes the measurement will end since the measurement time elapsed equals the preset duration The measurement has now ended successfully If you now press the PAUSE CONT key the instru ment will resume the measurement and go on measur ing for another 5 minutes so that the total measurement time assumes 10 minutes e twice the initial setting If you do this again the total measurement time will be 15 minutes i e three times the initial setting and so on This feature is useful for obtaining the averaged values from different positions of measurement
171. ither a hemisphere or a parallelepiped In addition you may choose between different loca tions of your test object e on the floor up against a hard reflecting wall or in a corner Surface MN Surface Surface Surface Surface Surface wm ar L L00m L 100m L 1 00 m mE o ccocwegv ocv pm W LOO m W 1 00 m W 1 00 m ie H 1 00 m H 1 00 m H 1 00 m E Dis 1 00 m Dis 1 00 m Dis 1 00 m Rad 1 50 m Rad 1 50 m Rad 1 50 m K2 2 0 dB K2 2 0 dB K2 2 0 dB K2 2 0 dB K2 2 0 dB K2 2 0 dB S 33 00m S 20 00m S 12 00m S 14 13m S 7 06m 3 53m w W W W W W The background noise measurement display The measurement control display Although the Nor140 Pos BGN Use Dl next and Although only 8 Pos Lega lets you measure the 1 I4 previous to go microphone positions Js 44 0 background noise level 2 between pages are shown there 2 77 5 in up to 40 positions 3 mac f are further pages 59 0 the background noise 4 pow so that a total of 40 56 9 a 44 9 B 5 level will in most situa 6 Dod microphone positions 6 ae tions vary so little from 7 can be covered 7 ns one microphone position 8 oo Use the b key 8 zm to another that it is for ZBGN 44 9 2LegA 71 6 most cases sufficient to W W measure the background noise level for one typical microphone position If you need to know which of the freque
172. kHz only frequencies up to 5 kHz can be reproduced However in most cases this is sufficient for noise source iden tification Note that the best format consumes twelve r4 r4 times as much memory as the simplest for storing a recording with a certain duration Recording gain The Nor140 has a large dynamic range exceeding 120 dB This means that if you try to play back the recorded sound after having transferred the files to your PC you will in most cases hear nothing The reason why is that most soundcard PC solutions sim ply can t handle the high dynamic range To overcome this problem you may introduce a gain applied to the recorded sound only the rest of the measurement is left unaffected The drawback is that the dynamic range for the recording is reduced accordingly so a sound recording overload may occur with no overload being detected by the instrument All other parts of the measurement are left unaffected by this gain setting The upper range for the recording will be the upper level for the instrument minus the selected recorder gain The upper range for the instrument is depend ent of the calibration but is normally 130 dB 140 dB peak The recording gain may be selected in steps of 6 dB 2x from O dB to 96 dB Enter a numeric value or use INC or DEC Recording duration The duration of a recording can be set from 1s in one second steps up to 9999 s close to three hours If the duration is set to O
173. l Lx 125 Hz 250 Hz Lx 2 9dB Lx 2 9dB 500 Hz Lx 0 8dB 1 kHz Lx 6 8dB 2 kHz Lx 12 8dB Lx 18 8dB Lx 24 8dB Octave band levels for male speech signal of A weighted level 66 dB 125 Hz 250 Hz 500 Hz Not included CD player and loudspeaker A CD player and loudspeaker for the excitation is not included in option 13 If you need ad vice for selecting suitable de vices please contact your local 4 Norsonic representative Norsonic can deliver a com mercially available small radio a with rechargeable battery Tivoli Audio PAL It comes with a jack socket for the excita tion signal from the CD player When ordered through Norsonic you will also receive a mounting bracket for mounting the radio on a tripod The diameter of the loudspeaker is about 6 cm and the frequency response is fairly flat from 100 Hz to above 10 kHz It has been reported that the selection of the CD player may influence the measurement We therefore recommend testing new equipment before you start the normal measurement tasks If you supply the exci tation signal electrically to the sound level meter BNC Lemo adaptor or cable available or measure close to the loudspeaker you should obtain excellent speech intelligibility ratings 1 kHz 2 kHz 4 kHz 68 9 dB 68 9 dB 65 2 dB 59 2 dB 53 2 dB 47 2 dB 41 2 dB Measurement overview General instrument description The figure below shows a typical set up fo
174. l frequency selective devices such as a filter will have a response shortly after removal of an input signal This will create a virtual reverberation time and the instrument can not measure below this limit Values close to these limits will also be infected If the measured reverberation time is below the lower limit for reliability the value will be marked by an adjacent question mark The table below shows the virtual reverberation times and the corresponding lower limits for a reliable measurement as a function of frequency and bandwidth Measuring according to the integrated impulse response method The instrument has to be set in a special mode of oper ation in order to measure the reverberation time Press MODE gt 2 for Reverberation Select the frequency mode On and the appropriate filter bandwidth 1 1 or 1 3 octave See the chapter Frequency analysis for details If option 10 Internal noise generator is installed you have to select the excitation type to impulse Press SETUP gt 7 and move the cursor filed to excitation type Ex type and select IMP by the use of the INC or the DEC key Press ENTER to leave the menu The letter R in the upper left corner of the display in dicates that the instrument now is in reverberation time mode By default the cursor is located on the 1kHz frequency band The cursor position determines the frequency band used to trigger the measurement If 1 kHz is not suitable as trigger
175. lable Storage Todes us cet o E cesa uta edt e edt eee des etos 64 Synchro an exampl iii bo seeded a eee te aH Ie 65 Settirig thesstorage Triode ti o Lese ce Lo t S 66 Chapter 13 Making hardcopies eeeeeeeeee esee esee nennen nnne nnnm nnne natnra sen iaaiiai 67 Settin gp for printeuts o crai perde eoe e idees ede eve aee da RERO 67 Printing out measured data ui ete RR DORADO ns aces CEDE EE RR TEE ANa 67 Chapter 14 Transfer of d ta to a PC intet eeeedecte ect iei teles 69 Select USB Osea coi bec te EI Pede OU Lee TR Ee A qa t s 70 Pas WO eo ttes secto adt scii rien atts e rape o Oris eh Oeste tie ce 70 NorXter installation procedure a eie rer e aa rem oec eae ne Pe PUER e dece 70 Virtual Instrument Nor1036InstallatiON procedure ssss e 73 Usingithe Normter NorlO20 a A ES 73 UsirigMirtuallristramentINOr10306 erre itr rrt Ot e UO egeo p ONE este 74 Chapter 15 Signal input and Output iia 75 Signal Pta Lo aa 75 c PEE 75 Noise oUtpult eu te ee ca ee c E E ea Dg ac ea 75 cipi PX TELE EU O TON I DL TI Ea ARI 75 x Contents Chapter 16 Chapter 17 Chapter 18 Chapter 19 Trigger GME alli ett Ae a 8 atari as a ceed ooh eMail tt wheat ed a AM Se Setting the trigger codicia R aa een ne 78 Manual HIS EE 78 Clock Ae oed tdt A A ERR 78 ExternalittlgOel aca rte eec trate ra RO eA EN Aa 79 Eevel abovestriggersc so irem a ege neta ted at ed roD e Reeds 79 Record
176. lity There are eight percentiles shown out of which one is freely selecta ble The class width is 0 2 dB over the entire 130 dB range The statistical distribution calculation applies to the Norsonic Nor140 Instruction Manual spectral weighting networks A and Z or C as well as all the individual filter bands if applicable The back erase feature which deletes the ten most recent seconds of acquired global data prior to a pause upon resuming updates the statistics buffers as well to maintain consistency For the statistical sampling the instrument makes use of the F time constant irrespective of what time constant s the frequency analysis as such employs The fixed percentile levels offered by option 4 are 1 0 5 0 10 0 50 90 95 and 99 In addition one of these percentiles is subject to user definition and can be set to anything from 0 1 to 99 9 both extremes included Note that you don t have to define the percentile prior to the measurement You may redefine the percentile as many times as you like even after the measurement For every frequency band measured However once you start another measurement or switch off the instrument only the selected percentiles will be available to keep the amount of stored data lower Reverberation time A typical Nor140 application is to serve as the acoustician s little blue tool This will require the ability to calculate the reverberation time in octaves and thir
177. low Selecting noise type and level Press SETUP and 7 for selecting noise set up menu A dialogue box as shown in the adjacent figure will be shown Use the arrow buttons below the display to move the field cursor Use the INC and DEC key to change the content The gain may be entered as a numeric value Press ENTER to terminate a key in operation e Gen switches the signal generator on off e f Sync is on and Gen is off the signal will be switched on when a measurement starts and be switched off after the measurement is ended This is used for reverberation time measurement with noise excitation e The noise type may be selected white or pink A pink noise will have similar levels in all fractional octave bands within the main frequency range for the generator 16 Hz 20 kHz Gain is used for setting the signal level The figure indicates dB relative to 1 volt for the broadband sig nal Press ENTER to leave the menu after set up Setup menu Noise ctrl Gen Sync ON Type WHITE Gain 20 dB Rev setup Ex type NOS Ex time 4 EIBRWGS Norsonic Nor140 Instruction Manual Extension for reverberation measurement When the instrument is equipped with option for measuring reverberation time Option 9 the noise generator may be used for the excitation The setup is done in the noise control menu as shown on the figure e The excitation type Ex type may be selected impul
178. lso able to predict the absolute rating of the speech transmission quality with respect to intelligibility when comparing different listening spaces under similar conditions or assessing a speech communication channel Norsonic Nor140 Instruction Manual Development of STI The basis for the STI index is that the intelligibility of speech is largely based on the slow modulation of the strength of the sound pressure signal that acts as a carrier In the STI methoa the carrier is a stationary gaussian noise signal divided in seven bands in octave steps ranging from 125 Hz to 8 kHz The bandwidth of each band is one half octave Each of the bands is modulated with one of 14 modulation frequencies The modulation frequencies are selected in one third oc tave steps from 0 63 Hz to 12 5 Hz This gives in total 98 combinations In the STI context the square of the sound pressure is called intensity The intensity is the quantity being modulated A small loudspeaker playing the modulat ed excitation signal acts as a talker The sound in the listener position is received by a microphone The level and the degree of modulation in each octave band is used to determine the speech transmission index Noise and reverberation in the room will reduce the observed degree of modulation The method also considers the effect of the most com mon types of distortions such as harmonic distortion and intermodulation However other forms of non lin e
179. lta converter with an effective sampling frequency of 48 kHz The anti alias ing filter is a combination of an analogue and a digital filter Frequency weightings Simultaneous measurement of A and C weighting or A and Z weighting 1 1 octave band or 1 3 octave band levels may be measured simultaneously if op tions providing these weightings are installed Filters 1 1 octave filters 0 5 16000 Hz class 1 digital IIR filters base 10 system IEC 61260 1 3 oc tave filters 0 4 20000 Hz class 1 digital IIR filters base 10 system IEC 61260 Level detector Detector type Digital true root mean square RMS detection and peak detection resolution 0 1dB which may optionally be increased to 0 01 dB for indicated levels in the range 9 99 to 99 99 dB Crest factor capability The crest factor is only lim ited by the peak value of the signal Time weightings and measured functions Simultaneous measurement of the following functions e F time weighted sound pressure level instantane ous e Maximum F time weighted sound pressure level e Minimum F time weighted sound pressure level e S time weighted sound pressure level instantane ous e Maximum S time weighted sound pressure level e Minimum S time weighted sound pressure level e time weighted sound pressure level instantane ous e Maximum I time weighted sound pressure level e Minimum I time weighted sound pressure level Norsonic Nor140 User Guide
180. ltispectrum measurements basic time profile 1 Set up the instrument to make time profile measure ments as described in Basic time profile measure ments 2 Press SETUP gt 4 and activate the filters as described in the chapter Frequency analysis Navigate set the parameters and leave the menu in the usual manner The instrument is now ready to make multispectrum measurements Units equipped with enhanced profile extension Instruments with enhanced time profile extension installed have a few more things to set To set up for multispectrum measurements en hanced time profile 1 Set up the duration and resolution 2 To gain access to the profile function activation menu press SETUP gt 3 L t par This menu looks as shown below 3 Navigate in the menu as usual and use the INC and DEC keys to activate the functions required for your task Deactivate those that you won t need A 1 means activated and a 0 means deactivated This menu is used to activate deactivate e the A weighted functions to be measured e the C or Z weighted functions to be measured e the filter band functions to be measured Use the NETW key to switch between A weighted func tions the C Z weighted functions and the filter band functions Functions to log setup menu to gain access to the C Z weighted func tions and the filter band functions as well Setup menu with multiple time constant optio
181. ltra M3 8 hours External pc 11 16 volt Power consumption ap proximately 1 2 watt dependent on selected modes of operation External DC source should have source impedance less than 1 ohm and be able to supply at least 300 mA The mains adaptor Nor340 is recom mended for use with the instrument If the external supply falls below 9V the instrument will use the internal batteries if available If the instru ment has switched off due to loss of power or insuf ficient supply voltage the instrument will automatically switch on and resume normal operation after reapply ing the external DC supply Socket for external bc 1 3 mm plug negative volt age on centre terminal The instrument will automatically switch off if the bat tery or external voltage is too low for operation within the stated specifications The maximum battery volt age for conformance testing is 4 x 1 6 V 6 4 V The instrument has a calendar clock powered from the batteries or external DC supply The clock is sup plied from a charged capacitor during change of bat teries Contact your Norsonic service department for change of this component After replacement the in strument need factory calibration and to re install the options Display The display is a monochrome transreflective LCD graphical display with 160x240 pixels WxH with au tomatic temperature compensation for contrast and viewing angle Pressing the light key illuminates the display T
182. m 18 35 16 Windscr ON Preamp ON FSPL 404 S noise ON 7 0 1 Corr par C ud A 37 2 RWGS RWGS Correction Corr par PreAmpAttn Random 1 Prezan Windscr ON Nos COMP Preamp ON S noise ON 0 1 1 COP T par RWGS RWGS RWGS Setting the amount of attenuation e n the Correction menu press 1 Corr par to gain access to the correction parameter setup menu Press 2 to gain access to the attenuation setting itself Never change this setting unless you know what you re doing Use the numerical keypad to set the attenuation value Press ENTER twice to leave the menu See Fig on the previous page for menu details Self noise compensation The displayed values for A C and Z weighted levels may as an option extension 18 be corrected au tomatically for the self noise of the microphone The noise levels for each of the spectral weightings must be specified The correction is applied by unlinear level subtraction The option allows levels close to the self noise to be displayed with reduced level linearity error When the level is equal to the self noise level the correction is 3 dB See chapter Compensation and correction Norsonic Nor140 User Guide Correction Random Windscr ON Preamp ON S noise ON 1 Corr par RWGS RWGS Correction Corr par Noise correction T 1 Pre amp Random Windser ON 22 ives ay Preamp ON S
183. m 200V to about 70 V A correction network is applied auto matically to compensate for the change in frequency response of the microphone due to the lower polarisa tion voltage The nominal response for the high level correction network is shown in the adjacent figure Note that the needed correction will depend on the type of microphone and shall only be applied when using microphone cartridge type Nor1225 Activating the high level range e Press SETUP gt 5 Lvl range to gain access to the level range setting menu Navigate in the menu as usual Preamplifier attenuation The instrument has the ability to correct for the attenu ation in the preamplifier Typical value of the attenua tion is 0 7dB The correction can be set in the range 0 0 to 9 9dB The correction can be switched on off to facilitate applications of other transducers without pre amplifier The correction is automatically switched off if ICP type of preamplifier is selected Activating the preamplifier attenuation e Toactivate the preamplifier attenuation press SETUP gt 1 Instr gt 6 Correct to gain access to the Cor rections menu Navigate in the menu as usual and activate the correction parameter Preamp by means of the inc and dec keys Do the same to deactivate Preamplifier attenuation activated is indicated by a G for Gain in the lower line of the display Correction 80 ee 05 12 55 111025 Rando
184. m with furniture rectangular machinery or industrial room 0 2 Irregularly shaped room with furniture irregularly shaped machinery or industrial room 0 25 Room with upholstered furniture machinery or industrial room with small amount of acoustical material 0 35 Room with acoustical material on both ceilings and walls 0 5 Room with large amounts of acoustical material on ceiling and wall Y Calculating the A The value of the mean Ay acoustic absorption coefficient a is estimated 5 by using the above table The value of A is then given in m by A axS in which S is the total area of the surface of the test room walls ceiling and floor in m 109 110 Chapter 22 Sound power Specific requirements Examples of permitted reflecting planes outdoors in clude compacted earth artificial surfaces such as concrete or sealed asphalt while for indoor measure ments the reflecting plane is usually the floor Take care to ensure that the reflecting surface does not radiate any appreciable sound energy due to vi bration The reflecting surface must be larger than the pro jection of the measurement surface on it The sound absorption coefficient details on this are given in the ISO 354 of the reflecting plane should preferably be less than 0 7 over the frequency range of interest This requirement is usually fulfilled when out door measurements are made over concrete sealed asphalt or stone surfaces
185. mally consists of a seismic mass mechanically connected to the accelerometer base through a piezoelectric material Piezoelectric materials have the property of producing electrical charge when bent and twisted even shear forces will work here Basically a charge is generated Depend ent of the type of transducer this charge may be the output signal or the transducer includes an ampli fier delivering an output signal with low impedance A popular type of transducers is the ICP or CCP type These are powered by aconstant current through the signal cable and deliver an output voltage which is the sum of a constant voltage and an AC voltage proportional to the acceleration Accelerometer Many types of acceleration sensitive sensors exist For connection to Nor140 sound level me ter the easiest is to apply an ICP or CCP type This type of transducers has low output imped ance and may be supplied through a coaxial able Nor1270 Sens 10 mV ms 23 g and Nor1271 Sens 1 0 mV ms 3 5 g are recommended Connect the accelero meter through the BNC Lemo cable Nor1438 and the BNC to microdot adaptor Nor1466 You also need a BNC BNC female connector See the figure below Alternatively a charge sensitive accelerometer may be used and coupled to the normal microphone preamplifier Nor1209 through the adapter with BNC input Nor1447 2 and the BNC to microdot adaptor Nor1466 The voltage sensitivity will depend on the total capacitance of
186. measurement as soon as the background noise level has been reached by pressing STOP The calculation of the reverberation times are automatically performed as soon as the measurement is terminated and the values are shown in a table The table shows the calculated reverberation time for each frequency band and for the spectral weighting networks A and C or Z weighting If the rever beration time measured is too short compared to the values in the table for minimum reverberation times a question mark will be shown to the right of the value If the signal to noise ratio is insufficient for calculating the reverberation time the sign will be displayed instead of a value Press FUNC for displaying T20 or T30 as appropriate After the measurement you may inspect the level profile of the measured signal by pressing the key 2oA The time profile will have a resolution of 10 ms Note that the logging of the profile starts when you press the start button the impulse may therefore be located outside the displayed time limit Move the cursor to scroll along the time axes You may com press the display by pressing the key DI The factor for compression is displayed as C 2 etc In a similar way the graph may be expanded by pressing the key K To store the values of reverberation time press STORE and the result are stored and automatically assigned a file number displayed at the top of the display The values may later be retrieved b
187. ment or decre ment the current setting of the parameter Alterna tively use the keypad to key in the required value whenever applicable The sign will appear in the lower line of the display whenever the instrument accepts numerical inputs f you use the NUMERICAL KEYPAD be sure to press ENTER before moving to the next field to al ter This is not needed when you use the INC and DEC keys E is shown on lower line as a prompt Toleave the menu putting changes into effect press ENTER There is no CANCEL function available so com plete the action Reenter if you make a mistake Screw only Microphone cartridge Default cartridge is designed for finger tight OEE 200V polarisa tion voltage Microphone preamplifier ou but this can be switched off To fasten preamplifier screw it on here Preamplifier socket Front plate Display Instrument body AC out SD card ise External power input socket Multifunction socket Keyboard USB RPM input Battery Compartment Clock Clock The date and time setting Y M D Press SETUP gt 1 Instr gt 3 06 08 24 Clock to produce this H M S dialogue box 13 03 Set clock BiRWGS Select preamplifier The instrument may be used with either the normal mi crophone preamplier select Standard or with a pre amplifier of the ICPO type The last is often used for accelerometers To set the polari
188. n left and without the multiple time constant option right Norsonic Nor140 Instruction Manual If you fail to activate functions for the filter bands there will be no multispectrum data either Making multispectrum measurements Multispectrum measurements are made in the same way as ordinary time profile measurements The only difference lies in the fact that the multispectrum meas urements log the spectrum as a function of time and not just the broadband values To go between level vs time and level vs frequency 1 Make sure the instrument is in profile mode a A dis played in the upper left corner of the display If not press the ZA key to enter profile mode 2 Use the fot key to go between display of level vs time and level vs frequency To move the cursor along the frequency axis 1 Make sure the display shows the spectrum If needed use the fot key 2 Use the and the P keys to move the cursor along the frequency axis 3 Use the M and the Dl keys to move the cursor to either extremes of the spectrum Are you going to use C or Z weighting as spectral weighting function This is set up in the 2nd network menu press SETUP gt 1 Instr gt 5 2nd netw and navigate as usual 49 50 Chapter 9 Multispectrum measurements To move the cursor along the time profile axis 1 Make sure the display shows the time profile level vs time If needed use the fot key 2 Use the d and the f k
189. n is installed left and when it s not right gt V Missing percentiles There may be percen Ay tiles that fail to produce values in the table lt This is because you have not measured for a time long enough to provide the necessary number of samples Statistical sampling which should not be confused with the sampling of the analogue to digital conversion takes place 10 times a second For comparison the sampling of the analogue to digital conversion runs at 48kHz Since the statistical sampling takes place 10 times a second it will take 10 seconds to produce 100 sam ples You will need at least 100 samples to be able to calculate the 1 percentile Likewise for the 0 196 percentile the minimum time required will be 100 seconds Measurements whose duration are shorter than these minimum limits will not produce percentile values for all possible settings of the percentiles To produce the measurement duration setup menu Press SETUP 2 To leave the menu press the enter key Statistics Even if your instrument is equipped with the optional extension 4 statistics the percentiles table will fail to produce values for all percentile settings unless the measurement duration is sufficiently long see the Missing percentiles side bar below left for more on this The sound level meter display Elapsed duration Display top Time constant 5 TS scale S ms Preset duration displayed REIR
190. ncy bands After a successful RESULTS that contribute the most to the calculated Lya set of measure ET Bc D value switch to global frequency mode make ments has been Lega tue The results a measurement and press the A Prew key The made the results BGN 44 0 can also be spectrum will now appear a weighted on the screen je presented like y 0 0 printed out purely a display function the measured data are not I e p e Turn to Making affected and the frequency band s contributing the y E hardcopies for a most should now be easy to spot LWA 75 1 sample lt Norsonic Nor140 Instruction Manual The environmental correction factor K accounts for the influence of undesired sound reflections from room boundaries and or reflecting objects near the source under test The magnitude of this environmental correction factor depends principally on the ratio of the sound absorption area A of the test room to the area S of the measurement surface The magnitude does not depend strongly on the location of the source in the test room When measuring in accordance with the ISO 3746 the environmental correction factor K is obtained from this graph by entering the abscissa with the appropriate value of A S 4 a Description of Room 0 05 Nearly empty room smooth hard walls made con crete brick plaster or tile 0 1 Partly empty room room with smooth walls 0 15 Room with furniture rectangular machinery or in dustrial room 0 2 Irre
191. ne cartridge sensitivity you may key this in using the numerical keypad However doing so will never replace calibration with a sound Norsonic Nor140 Instruction Manual calibrator as the sensitivity adjustment procedure will be unable to reveal possible microphone preamplifier or extension cable malfunctions No need to adjust the full scale setting Since the Nor140 has a 120 dB dynamic range 10 130 dB SPL the 80 dB bar graph range is a display limitation only Hence you wont have to bother with setting the full scale before you enter the calibration menu Furthermore since the Nor140 automatically enters C weighted mode you won t have to bother with the calibrator frequency either However you may have to adjust the display top scale setting to see the top of the bar graph Use the INC and DEC keys for this before you enter the calibration menu Carrying out the calibration You will need a sound calibrator of sufficient accuracy ie a class 1 sound calibrator as defined by the IEC 60942 standard such as the Norsonic sound calibrator Nor1251 or Nor1253 Do as follows 16 Chapter 3 Calibration 1 Mount the calibrator onto the sound level meter 5 Set the sensitivity To set the sensitivity correctly Mount the sound calibrator onto the microphone as shown to the right Switch on the sound calibrator and wait until the level has stabilised Information on how long time this will take should be available from th
192. ng the key I C 2 means two time expansion To store the values of reverberation time press STORE and the result are stored and automatically assigned a file number displayed at the top of the display The values may later be retrieved by press ing RECALL However no profile will be shown from re called files since the profile is not stored with the result Measuring according to interrupted noise method The instrument has to be set in a special mode of op eration in order to measure the reverberation time and require option 10 Press MODE gt 2 for Reverberation The letter R in the upper left corner of the display indi cates that the instrument now is in reverberation time mode You have to select frequency mode On and the appropriate filter bandwidth 1 1 or 1 3 octave See the chapter Frequency analysis for details Press SETUP gt 7 and move the cursor field and use INC or DEC key to set Generator Gen to OFF e Synchronisation Sync to ON e Select the wanted noise type e Set the gain to select the excitation level O dB is the highest and 50 dB is the lowest level NB Start with a low level if you are unsure about the gain of your amplifier 99 100 Chapter 21 Reverberation time measurements Minimum reverberation times Frequency Virtual RT Virtual RT Lower limit 1 3 oct Lower limit 1 1 oct 0 p 0 24 EA EA 0 12 AAA ae gie 2 fpe ER 0 03 ESTA
193. nitions for airborne sound insulation ssssssssssseeees Terms and definitions for impact sound insulation Sutveyandengirieering tmelthod a o eO bai ien teat Airborne sournd insulatlon Ss General de ete m o ae e tee eu me atts a ONE OE Od peu GEH Noise excitation x eco meinen A bo ed eda cerit e ede Measurementiot sourd leveli or tore eee bert Measurement of reverberation time sssssssssssssssssssseenee nennen enne nnne Calculating the Airborne Survey result Calculating the Airborne sound insulation according to the Engineering method 20 Stor arnd recalls er ape on i acere Eee 121 Averaging levels or level differences sss rere 122 Impactsourid ins latlOna essence RR n mtr eee ina 122 IMPACt SxcitallOnsawis waives dd ia 122 Measurement of so nd level 1 tret e te RE ree eee ERES 122 Reverberatorrtilrie ro ege t ed E ede REE eee dtes 123 Calculating thie SUrvey result s uc te t Rt S er M HUE 123 Calculating the impact sound insulation according to the Engineering method 124 Salon RR RUD EO t e D er eU DU RR Ene IER Partly re use ofprevious measurements Facade InsulatiOi sss eo t ree IH IO rer i RA Re SU EE gre pre N erue TS Terms and d finitions tier aa a e e Noise excitatiOri aiii dd da Measuremetitiot so nd levels s ut ttt aer tese Measurement of reverberation time ooooononocinnn
194. nsions installed 8 Extension menu 8 Options available 9 Norsonic Nor140 Instruction Manual 167 168 Appendix 1 Index F Facade insulation 125 Fast Fourier Transformation See FFT FFT 143 Calibration 144 Corrections 144 Specification for FFT 145 Format 58 Free field microphones 16 Calibration 16 Frequency analysis 27 A weighted spectrum 31 Activating the frequency mode 29 Front panel keys 14 Functions 2 23 G Global 37 H Hardcopies 67 Headphones 76 Highpass filter 152 High sound levels 92 158 ICP 75 Impact sound insulation 122 Terms and definitions for impact sound insulation 117 impulse response method 98 input terminal 75 interrupted noise method 99 K Keeping track of the measurement mode the file was stored in 63 Keyboard 14 Keyboard lockout 65 L L t 41 Presenting the L t as a table 41 Level detector 153 Low sound levels 91 Magnetic fields 165 Manual storing 64 Markers 46 Adding markers to a measurement 46 Other markers inserted by the instrument 47 P and S markers have priority 47 The key to use 46 Measurement mode Keeping track of the measurement mode the file was stored in 63 Measurement range 152 155 Measuring vibration 146 Memory 57 63 earing a single file 63 earing folders or the entire memory 63 emory structure 57 etrieving stored setups and data 62 D card 57 elect the device for storing 58 andard set up 62 oring a measurement 60 oring a measurement setup 58 Menu
195. o no reflecting objects that are not part of the source under test shall be located inside the measurement surface Hemispherical microphone positions If there is only one reflecting plane the microphone po sitions lie on the hypothetical hemispherical surface of area S 2n enveloping the source and terminating on the reflecting plane If the source under test is in front of a wall S xf and if it is in a corner S 0 5r FP Microphone positions on a hemisphere key microphone positions The Fig below left shows the location of four key mi crophone positions each associated with equal areas on the surface of the hemisphere of radius r If source is installed adjacent to more than one re flecting plane the Figs shown on the next page are used to define a suitable measurement surface and the microphone positions Additional microphone positions Sound pressure level measurements are required at additional microphone positions on the hemispherical measurement surface if a the range of sound pressure level values meas ured at the key microphone positions i e the difference in decibels between the highest and lowest sound pressure levels exceeds twice the number of key measurement points or b the source radiates noise with a high directiv ity or c the noise from a large source is radiated only f rom a small portion of the source e g the openings of an otherwise closed machine If condition
196. of a paused measurement will cause the ten seconds acquired immediately before the pause to be erased This applies to the global measurement but not to the profile Assume you have set up the measurement to also include profile and that the measurement is running If you press pause the global data acquisition will be halted but the profile will still acquire data These data will be marked P for pause to denote that they were acquired in pause mode and that they do not participate in the global level assessments Th k The line denotes Ww RM periods are o44l A marked APeak 72 0 mi Er When you later press pause again to resume the amount of periods marked as paused will be expanded backwards in time about 10 seconds to include peri ods acquired in the time span subject to back erasure in the global mode The reason why we designed it this way was to provide you with the complete overview if you later transfer the acquired data to your PC you will be able to do calculations on any parts of the profile while at the same time you ll be able to see the intervals that didn t take part in the global assessments Consequently the duration of the measurement will seem ambiguous The global duration will be less the pause and less any back erase while the profile will have a duration including the pause length and without back erase This chapter deals with profile measurements only For details
197. of the bandpass filters if the filter option is installed Use INC or DEC to modify the displayed value After pressing the START key the instrument will start a record the selected delay after the level goes above the threshold If a negative value has been en tered for the delay the record will start the specified number of seconds before the triggering condition was fulfilled The minimum duration the level must stay below the threshold before the record is terminated is 1 second Therefore the record will last one second after the trigger condition is not longer fulfilled or until the selected duration has exceeded Note that a new event has to occur before a new record is started The level has to cross the threshold from below A new record can not be started before 10 seconds after the termination of the previous If you want to make an automatic record lasting for the whole measurement set a very low threshold e g 19 9 dB and select the duration to O s Listening For listening to the recorded sound we recommend to transfer the file to a PC This may be done by transfer ring the measurement data with the recording to a PC or by storing on the SD card and plugging the card in a card reader In both cases we recommend to use the program NorXfer Nor1020 for taking care of the menu structure When the result is analysed with the PC program NorReview Nor1026 the measurement and the sound recordings are automatically c
198. of the reference box in this case the measurement distance d is the distance between the measurement surface and the reference box b a hemispherical surface or partial hemi spherical surface of radius r For sources usually mounted and or to be measured in rooms or spaces under unfavourable acoustical condi tions e g many reflecting objects and high levels of background noise the selection of a small measure ment distance is appropriate and usually dictates the selection of a parallelepiped measurement surface For sources usually mounted and or to be measured in large open areas under satisfactory acoustical conditions a large measurement distance is usually selected and in this case the hemispherical measurement surface is preferred For measurements on a series of similar sources e g machines of the same type or a given family of equipment the use of the same shape of measure ment surface is required A test report shall always be made and the construction of the reference box the size and shape of the measurement surface as well as the measurement distance d or the radius of the hemisphere r shall be described in the test report The figures shows the characteristic dimension d for the different locations of the source under test Reference box on three reflecting planes Norsonic Nor140 103 Instruction Manual Rectangular parallelepiped For the rectangular parallelepiped reference box there
199. on global frequency analysis see the chap ter Frequency analysis Making measurements All you need to do to set up the Nor140 to expand the measurements to also include the time profile is to de fine the time resolution To define the duration and the resolution 1 Press SETUP 2 Units with the option 6 installed will then produce the measurement duration menu See side bar for details 2 Set the global duration 3 Move down to resolution and set as required Make sure that number of periods N is below the maximum value Navigate and leave the menu as usual If you ve set up a profile resolution different from i e shorter than the global measurement duration the instrument will log the time profile in addition to the global measurement Theeffectof pressing STOP before resum NS ing If you terminate an ongoing measurement AY prematurely by pressing the STOP key and later resume the measurement by pressing PAUSE CONT an S marker will be added to the period within which the PAUSE CONT key was pressed i e we mark out the first period after resumption To start the time profile measurement e Press START To switch to see the time profile e Press the ZA key To return to global mode press the key again The features available while measuring described in the chapters Simple sound measurements and Frequency analysis apply even here M A Functions measured in the basic time profile mode In the b
200. or Noise output The signal is available on the general I O socket See the sections Noise generator and Technical specifica tions RPM The instrument is equipped with an input for tachom eter signals marked RPM Currently this input is re stricted to special applications only Ask the factory for more information 76 Chapter 15 Signal input and output Signal output The sound level meter Nor140 is equipped with a sig nal out terminal The signal is a replica of the micro phone or input signal You may use the terminal for listening to the measured signal or you may use it for other purposes The gain for listening is set via the selection of dis played full scale Full scale on the display corresponds to 100 mV on the signal out terminal Although the se lection of full scale will not affect the measurement it will determine the sensitivity for the signal out Use the INC and DEC keys to adjust the gain The gain may be varied over a range of 60 aB in 10 dB steps The signal out terminal can drive loads with an im pedance down to less than 16 ohm but we normally recommend a headset with 32 ohm impedance Even a short circuit will not affect the measurements but should be avoided due to an excess power consump tion The signal output terminal is a 3 5 mm stereo jack compatible with most headphones Both channels have the same signal but are driven from separate amplifi ers and should therefore not be connected
201. orrection has to be switched on to obtain the stated specifications when the windscreen is mounted The nominal correction for the windscreen correction network is shown in the figure above Activating windscreen correction e Press SETUP gt 1 Instr gt 6 Correct to gain access to the Corrections menu Navigate in the menu as usual and activate the correction parameter Windscr by means of the INC and DEC keys Do the same to deactivate Windscreen correction activated is indicated by a W in the lower line of the display 48 Windscreen correction Frequency Hz Correction Random Windscr ON Preamp ON S nnoise ON 1 Corr par RWGS 157 158 Chapter 27 Technical Specifications Correction for High Level Mode dB o 70 5 HLcom 71 10 100 1 10 1407 1 10 fa Frequency Hz Level Range By lowering the polarisation voltage the level range can be extended with out changing the microphone cartridge This feature shall be used in combina tion with the Nor1225 cartridge only HIGH RWGS High levels As an option the instrument may measure levels 10dB higher than stated as the standard range The extend ed measurement range is obtained by reducing the sensitivity of the microphone through the application of a lower polarisation voltage When this option is se lected the polarisation voltage is lowered fro
202. other acoustical parameters Typical applications include the measurement of reverberation time as required in the International standards for building acoustics giv en by the ISO 140 series The instrument calculates the reverberation in the range 63 Hz to 8 kHz when 1 1 octave bandwidth is selected and in the range 50 Hz to 10 kHz for 1 3 octaves What is reverberation time Assume that you switch on a sound source in a room equipped with a microphone system You will note that the sound level will not reach a steady level immediate ly The reason why is that the sound will consist of the direct sound radiating from the source in combination with reflected sound and these reflections take time before they reach the microphone If you now switch off the sound source the sound will take some time to decay For most rooms without significant echoes the level will decay linearly with th time until the noise floor is reached The time it takes for the sound pressure to decay by 60 GB is called the reverberation time However the calculation in Nor140 is based on the decay in the range 5 dB to 25 dB be low the stationary level and extrapolated to obtain the 60 dB range value Reverberation times measured this way are often denoted T20 In a similar way T30 is based on the decay in the range 5 dB to 35 dB below the stationary level Two methods of measuring decay curves are de scribed in the referred International Standards The in terr
203. oupled Please contact your Norsonic representative for further information Insert a reference tone as a recording When listening to a recording it may be required to make the playback with the same actual sound level at the listener s ears as the original sound was at the spot of the actual measurement In such cases a reference tone with a pre defined level may be recorded dur ing the measurement and later replayed through the Norsonic Nor140 Instruction Manual listener s loudspeaker system at the spot of the replay The reference tone is activated by use of the CAL key during a running measurement provided that it has been enabled in the Ref tone menu The menu is displayed by pushing SETUP gt 1 Instr gt 8 Ref tone The reference tone feature is enabled by using the cursor keys to move the cursor to the upper position and selecting ON using the INC or DEC keys Ref tone Ref tone ON Type SINE Gain BRIU dB Ex time 10 Freq 1 0kHz The preset type gain and excitation time of the reference tone are edited in the same menu The type is either PINK noise or a SINE wave If the SINE is selected the actual frequency is set at the lower cursor position The default level of the reference tone is 120 dB This may be lowered by choosing a gain between O and 50 dB hence producing a reference tone in the 70 120 dB range The excitation time or duration of the reference tone after activation
204. pical values are 55 dB to 65 dB for acceleration values of 1 ms perpendicular to the diaphragm Sensitivity for magnetic fields The maximum indication for exposure to magnetic field of 80 A m and any orientation is typically less than 20 dB Size and weight Depth 30 mm Width 75 mm Length excl microphone preamplifier 210 mm Length incl microphone preamplifier 292 mm Weight incl batteries 410 g Norsonic Nor140 Instruction Manual Information for conformance testing Reference Sound Pressure Level 114 0 dB re 20 uPa The reference frequency is 1000 Hz Reference Level Range The instrument has one level range only Microphone Reference Point and Direction The microphone reference point is the geometric centre of the diaphragm of the microphone The microphone reference direction is from the microphone and along the axis of rotational symmetry for the microphone and preamplifier Battery voltage The instrument will automatically switch off if the battery or external voltage is too low for operation within the stated specifications The max battery voltage for conformancetestingis4 x1 6 V 2 6 4 V Electromagnetic Compatibility When the instru ment is tested for conformance to electromagnetic compatibility requirements the instrument should be in the measurement mode as this normally will gen erate the highest levels of emissions The highest susceptibility is normally observed when the display faces the
205. ports are halt ed until the following command is transmitted REMOTE LOGIN TO NORSONIC 140 The communication may again be blocked by sending REMOTE LOGOUT FROM NORSONIC 140 NorXfer installation procedure Note Do not connect the instrument to your PC before the procedure asks you to do so 1 Insert Norsonic Application CD into the CD drive A menu will appear Select installation of NorXfer 2 After a successful installation of NorXfer start the program and key in your license codes In case you have other Norsonic instruments using NorXfer V4 or higher just use the existing codes do not type in new codes If you have no earlier version with a code or have ordered other software where a license code is supplied use the following Company NOR 140 User Name NOR 140 Registration Code ANTKDDXAX1D5PA Found New Hardware Wizard Welcome to the Found New Hardware Wizard Windows will search for current and updated software by looking on your computer on the hardware installation CD or on the Windows Update Web site with your permission flead our privacy policy Can Windows connect to Windows Update to search for software Yes this time only Yes now and every time connect a device No not this time Click Next to continue Back Cancel Norsonic Nor140 71 Instruction Manual v EE NEN E000 6 ea Found New Hardware Wizard Hardware Installation t The software you are instaling for
206. pressure level versus time will in general contain information on the obtained station ary sound pressure level in the room L as well as the reverberation time A typical level versus time diagram is shown on the adjacent figure The background level is indicated as L Information about the decay will be given for t gt 0 The decay may be further processed to obtain the re verberation time The classical methods for the measurement of air borne sound in rooms defined in the ISO 140 and the ISO 3382 series of International Standards specify a stochastic signal for the excitation Although the room in most cases may be described as a deterministic system statistical spread from the random excitation will lead to a certain stochastic variation in the result which may be characterised by a standard deviation Norsonic Nor140 Instruction Manual L Vo MW e LN Ave hA or La 0 t Reverberation decay Therefore averaging of more measurements is nor mally needed to obtain results close to the stochas tically expected values Such averaging may for the classical method be combined with the spatial averag ing needed to obtain a mean value for the room Measurement with impulse excitation M R Schroeder 1 has shown that the expected decay in one particular observation point may be obtained without averaging by processing the impulse response between the excitation signal loudspeaker and the observation point
207. principal direction of propagation for the electromagnetic field For further information related to type approval periodic verification consult the factory 165 166 Index A Accelerometer 146 A weighted 31 A weighted spectrum 31 Absolute time 5 Airborne sound insulation 118 Terms and definitions for airborne sound insulation 116 Automatic storing 64 B Back erase 40 No back erase in profile pause mode 40 backup storage 11 Batteries 10 Building Acoustics 115 Airborne sound insulation 118 Facade insulation 125 Impact sound insulation 122 Service equipment sound pressure levels 128 Survey and engineering method 117 Terms and definitions for airborne sound insulation 116 Terms and definitions for impact sound insulation 117 C C weighting 21 Calibration 15 55 Engineering units 55 Calibrator 16 17 Charging 11 CIS value 142 Clearing 63 Clearing a single file 63 Clearing folders or the entire memory 63 Compensation 90 Diffuse sound fields 91 Low sound levels 91 Random incidence 91 Self noise 91 Windscreen 90 Conformance testing 165 D Date 13 Diffraction around the instrument casing 160 Diffuse response Diffuse sound fields 91 Random incidence 91 Diffuse sound fields 91 Digital inputs 162 Digital outputs 162 Duration 19 38 Measurement duration 20 Missing percentiles 20 E Engineering units 54 Calibration 55 How values are indicated 54 Environmental conditions 164 Extensions 7 Exte
208. r a STIPA measurement The sound source normally a small loudspeaker is acting as a talker The loudspeaker should be placed in the normal position for a talker either using or not using a public address system as required The level should correspond to the normal level for speech The signal to the loudspeaker is obtained by play ing the supplied audio CD Nor1034 with the record ed excitation signal Place the Nor140 sound level meter with the STIPA option installed in the place where you want the speech intelligibility to be measured Press MODE and select the STIPA mode Press the START button After about 15 seconds the estimated STI value and the cor responding CIS value is indicated on the screen 136 Chapter 24 Speech Intelligibility by STIPA Set up for STIPA measurement Selecting a loudspeaker for the excitation Most applications of the STIPA method require a loud speaker to act as a talker In this case the directivity of the loudspeaker should be close to the directivity for a real human speaker as speech intelligibility depends upon the directivity of the source therefore a mouth simulator having similar directivity characteristics to those of the human head mouth should be used for the highest accuracy when assessing the intelligibility of un amplified talkers Fur ther the frequency response between 100 Hz and 10 kHz should be flat The loudspeaker should be a single element design or using coaxial
209. re available for inspection during or after a measurement You may Switch between sound level meter display and frequency spectrum display Display the functions measured Display the result tables Change the spectral weighting function between A and C or Z weighting this depends on which one you measured Display the eight percentiles requires the presence of the optional extension 4 and set one of them as you like Store them for future use No SPL after the measurement During measurements the SPL value is updated eve ry second Once the measurement is over the SPL becomes meaningless A single SPL value cannot be used to characterise the measurement unless it represents some kind of maximum minimum or time integrated average It is thus not accessible post measurement To return to ready mode i e how the instrument behaved before the measurement was started press the EXIT key You will be prompted to store the data or press EXIT again In both cases the instrument will go back to ready mode The SPL will now be displayed again If you choose not to store the data by pressing EXIT again the measured data will be lost beyond retrieval Displaying the result tables As an alternative to the procedures shown on the next page you may display all the measured data in tables Press the TBL key to enter table mode Note that the look of the tables depends on whether you start from sound level meter
210. rement The acquired results are then present ed as a table If you are measuring very short rever beration times you may terminate the measurement as soon as the background noise level has been reached by pressing STOP The calculation of the reverberation times are auto matically performed as soon as the measurement is terminated and the values are shown in a table The table shows the calculated reverberation time for each frequency band and for the spectral weighting net works A and C or Z weighting If the reverberation time measured is too short compared to the values in the table for minimum reverberation times a question mark will be shown to the right of the value If the sig nal to noise ratio is insufficient for calculating the re verberation time the sign will be displayed instead of a value An overload is marked by Press FUNC for displaying T20 or T30 as appropriate After the measurement you may inspect the level pro file of the measured signal by pressing the key ZA The time profile will have a resolution of 10 ms Note that the logging of the profile starts when you press the start button the impulse may therefore be located out Norsonic Nor140 Instruction Manual side the displayed time limit Move the cursor to scroll along the time axes You may compress the display by pressing the key DI The factor for compression is displayed as C 2 etc In a similar way the graph may be expanded by pressi
211. ring units are selected the sensitivity still has to be speci fied in this way However if a calibration signal is pre sented to the input the indication will be in engineering units or decibel dependent upon the selected setup Use the INC or DEC keys as usual for adjusting the sensitivity in 0 1 dB step If you want to calculate the sensitivity some exam ples may clarify the procedure 55 56 Chapter 10 Engineering Units Example 1 A microphone with preamplifier has a sensitivity of 50 mV Pa or 0 05 V Pa The SI unit pascal Pa is now used as EU The logarithmic sensitivity will be yy s eil Send x If you set the sensitivity to this value and dB is select ed the sound pressure will be indicated in dB relative to 20 uPa If EU is selected the signal will be indicated in pascal Normal levels will correspond to the root mean square value RMS but the peak value will cor respond to the absolute value of the pressure peak Set the sensitivity level Ls to O dB The indication in engineering units will then correspond to the voltage in volt of the signal presented at the input terminal microphone socket Example 2 The combination of an accelerometer and an amplifier has a sensitivity of 20 mV ms The unit for accelera tion ms is now the engineering unit The logarithmic sensitivity will be L E red Ag Setting the instrument to this sensitivity and selecting EU will make the ins
212. ring the self noise The self noise of a sound level meter is the indication on the meter when the instrument is placed in a quiet place where the actual sound pressure level is consid erably 20 dB less than the self noise The self noise should be measured with the actual microphone after proper calibration of the instrument Note that a dummy microphone often used for check ing the self noise of an instrument cannot be used 91 92 Chapter 20 Compensation and correction Linearity error without and with correction Linearity error without correction 3 a pa e o z 1 l 0 0 2 4 6 8 10 12 14 16 18 20 Sound level above self noise level dB Linearity error with correction 3 2 T m Correction 1 dB to low Ke 5 1 Ideal correction 9 0 z S 1 dB to high 2 3 0 2 4 6 8 10 12 1 Sound level above self noise 4 16 18 20 evel dB Use of a dummy microphone will only indicate the electrical noise of the system and not the noise related to the acoustic impedance of the microphone If you don t have access to a required quiet place the instrument may be placed inside a closed vessel placed on a place with low vibration We recommend using some acoustic damping material in the vessel If you have the Trigger option Option 16 we recom mend to use the clock trigger for starting a measure ment after the ve
213. rinter can handle be sure to use the same set ting in the printer experiment with the printer type see above and unless you re in need of printouts with Ger man text set language setting to ENGLISH Printing out measured data To print out measured data be sure to visit the Prnt par menu first This menu lets you decide which of the meas ured functions should be printed out The menu comes in two flavours depending on whether your instrument is equipped with multiple time constants or not 67 68 Chapter 13 Making hardcopies To set which functions to print out Two printout examples a profile and a sound power meas 1 Press SETUP gt 1 gt 9 gt 1 Depend on options urement output 2 Use the cursor keys to navigate and the INC and DEC keys to set the functions to be printed A 1 means that the function will appear in the printout 3 Units equipped with the enhanced profile extension allow you to select which functions to log as level vs time Once you ve set up this table and pressed enter to put changes into effect the instrument will prompt you to decide whether this setup shall be copied to the Prnt par menu as well for convenience Note that this applies to profile printouts only A Ni OBNaBAOUaLE D e To start a printout 1 Set up everything as required 2 Press the PRINT key Sound Power Measurement According to ISO 3746 EN 23746 id ie Page 1 of 2 General Information
214. round noise level for one typical micro phone position To toggle between the measurement control dis play and the background noise measurement con trol display Use the FUNC key Measurement surface The sound power calculation requires the operator to select the correct measurement surface To select the right measurement surface 1 Press the SETUP key and choose the corre sponding selection in the sound power setup menu The selected surface is indicated by H for Hemispherical and P for Parallelepiped with an additional W or Cfor test objects placed against a wall or in a corner The selected sur face is also indicated by a simple diagram 2 Depending on the selected surface the measurement radius or the distance from the reference box i e the minimum box that fits around the test object must be keyed in The calculated area S of the total measurement surface will then be displayed 3 Finally key in the acoustic environment correction Ko Sound power results Based on the averaged sound pressure level of all the microphone positions the measured background noise level and the selections and corrections made in the sound power setup menu the Nor140 will display the final Lwa To see the sound power calculation results e Press the TBL key n addition to the overall results the impulsive noise values the Leeaxc Or Lpeakz level and the noise di rectivity of the test object for all microphon
215. roy low level signals in the microvolt range When you select the standard preamplifier by pressing SETUP gt 1 gt 4 Press INC if STANDARD is not displayed the signal input is an AC coupled input terminal with an input impedance of more than 600 kQ This mode is used when the ordinary preamp lifier Nor1209 is applied The signal terminal may also be used for more gen eral applications as for measuring the AC voltage from other transducers or sources The measurement range is from 10 volt peak to levels less than a microvolt dependent of the applied frequency weighting The cable Nor1438 with a BNC connector in the far end may be convenient for such applications p6 p p7 p p5 p p4 Norsonic Nor140 Instruction Manual ICP The input terminal pin 2 may also supply current to transducers of the constant current or ICP type This mode is selected by pressing SETUP gt 1 gt 4 and toggle the input to ICP A current of 4 mA from a 25 volt power source will then be supplied an connected transducer These types of transducers are often use measure ment of acceleration Nor140 able to measure down to 0 4 Hz will be well suited for such applications If you need a very long extension cable between the microphone and the instrument you may want to consider the ICPO type of preamplifier Nor 1207 This will allow a one conductor screened cable to be used Nor1207 may be delivered with either BNC or TNC out put connect
216. s The weighted values are all rounded to the closest whole dB If you want to go back to the menu for calculation press ENTER Press the MODE button if you want to return to nor mal mode of operation Calculating the impact sound insulation according to the Engineering method Select the building acoustic mode and press 4 for Impact Enter the value for the room volume V and press ENTER or move the field cursor to C and press ENTER for a calculator The calculator allows you to enter the length width and height of the room in order to calculate the volume The field cursor automatically moves between the fields as values are entered If you want to adjust any previously entered value use the arrow keys to move the field cursor to the wanted parameter The next set of values to be entered is the sound levels in the receiver room L for each one third octave band Recall a measurement by using the RECALL key or press START for starting a measurement If measured the values are automatically stored You are prompted to accept the recalled or measured values as a part of the averaged result Press ENTER alternatively STORE to accept or EXIT alternatively DEL if you don t want to accept You may repeat the loading of data to obtain the averaged results from more measurements The number of measurements that has been accepted for the averaging is displayed by a number N Press the TBL key to display the aver aged levels
217. s Option 3 One third octave frequency analysis and Option 9 Revereberation Time measurements are therefore required in addition to Option 11 The procedure described in the International standard specifies how to measure sound insulation by measuring levels and reverberation time in one third octave bands 117 118 Chapter 23 Building Acoustics Airborne sound insulation General When airborne sound insulation between rooms is measured one of the rooms is designated the source room and the other the receiving room A stationary sound field is generated in the source room by a suit able loudspeaker If a facade is measured the loudspeaker is placed outdoors and the outside of the building is then acting as the source room The description made here refers to the sound insulation between rooms but may also be adapted to the measurement of facades Noise excitation The applied method requires broadband noise to be used for the excitation The noise may be generated by the instrument if option 10 Noise generator is in stalled Sometimes it will be convenient to have no ca ble between the instrument and the loudspeaker for the excitation This may be achieved by using a radio transmitter for the noise signal contact Norsonic for more information or to use a power amplifier with an internal noise generator such as the Nor280 Another alternative is to play a music CD with recorded noise Norsonic can supply a CD with th
218. s 12 19 avigating in 12 Microphone check 18 Microphone input socket 152 Microphone preamplifier See Preamplifier Mode 63 Keeping track of the measurement mode the file was stored in 63 Multispectrum measurements 6 48 Making multispectrum measurements 49 Result tables 51 Setting up for multispectrum 48 To move the cursor along the time profile axis 50 To see the level vs time the profile graph of another frequency band 51 To see the spectrum of another moment in time 50 zoo NNNNN m N Noise Generator 88 Reverberation measurement 89 Selecting noise type and level 88 NorXfer 70 O Octaveband 29 Options See Extensions output control lines 163 P Password 70 Pause 22 The back erase feature 23 Polarisation voltage 11 power fail 11 Power Sound 102 Power supply 156 Preamplifier 12 13 158 Attenuation 158 Prepolarised microphone 11 Printouts 67 Profile 37 40 No back erase in profile pause mode 40 R Random incidence 91 RASTI 132 Real time frequency analysis 4 Recording 80 Formats 80 Recording duration 81 Recording gain 80 Setup for a recording 81 Starting a recording 81 Reference Spectrum 84 Activating the ReferenceSpectrum features 84 Digital output lines 86 Editing a selected Reference Spectrum 86 Entering a new Reference Spectrum manually 85 Go NoGo Quality Control feature 86 Selecting the Reference Spectr 84 Using a previouslymeasured spectrum 85 reference tone 83 Relative time
219. s are only shown during a measurement never after the measurement is over unless SPL is logged as a function of time To produce the table of measured results using the other spectral weighting function press the NETW key while in the table There are two spectral weighting functions available A and C or Z weighting The latter should be set by you prior to the measurement Even before you enter the table you may use the NETW key to view the results of applying the two spectral weighting functions The result table Once you ve pressed the TBL key the display will typically look like this To return to READY mode i e how the instrument behaved before the measurement was started press the EXIT key You will be prompted to store the data or press EXIT again In both cases the instrument will go back to READY mode The SPL will now be displayed again If you choose not to store the data i e you did press EXIT a second time the measured data will be lost beyond retrieval Storing is dealt with later 0 08A 0 05 A Measure Leq 40 9 Leq 37 9 Spectral FMax 47 6 FMax 39 5 ure menttime Pymin 369 pMin 373 Weighting LE 49 4 LE 44 9 applied Peak 62 0 Peak 53 5 I Leq 44 5 I Leq 46 4 F TmX5 47 6 F Tmx5 39 5 FSPL 379 FSPL E Dm Measurement is running Observe that once the measurement is no longer run ning no SPL value is available Units not configured for the G
220. s way you may start a measurement at the same time every day The duration and time resolution of the measurement are set as usual Alternatively if you set the synchro measurement store function Press SETUP gt 1 gt 1 the instrument will start a measurement at the pre selected time store the result and start a new measurement The duration of the measurement will be as selected but adjusted so the start of the periods are synchronised with the change of the hour for the real time clock in the in strument Example A measurement with a duration of V hour is started 09 40 The first period will end in due time to start the next measurements 10 00 10 30 11 00 etc External trigger The external trigger function is selected by moving the field cursor to the field External and pressing ENTER After pressing the START key the instrument will start waiting for an externally supplied binary voltage signal 3 3 volt CMOS The signal has to be applied to DI 1 pin no 8 on the general I O socket See the specification section for further information If you set the repeat measurement function Press SETUP gt 1 gt 1 the instrument will start a new meas urement after the first is finished and wait for the trigger condition to be satisfied again If you want to interrupt a waiting for trigger opera tion press the STOP key Level above trigger The level above trigger function allows a measure ment to be started as
221. sation voltage for the standard microphone e Press SETUP gt 1 Instrument menu gt 4 Pre amp select Standard and use the vertical cursor keys to select 200V polarisation voltage ON or OFF For the normally supplied microphone the polarisation voltage shall be ON Setting the time and date To set the time and date e Press SETUP gt 1 Instr gt 3 Clock Use the cursor keys to navigate in the menu and INC and DEC to alter a setting or use the numerical keypad to key in a value Numerical inputs must be terminated by ENTER to enable navigation between the param eter fields again Move the field to Set clock and press ENTER to leave the menu putting changes into effect i e setting the time and date Norsonic Nor140 Instruction Manual 13 14 Chapter 2 Taking a closer look The front panel keys of the Nor140 Cursor keys to navigate in the menus and to operate the graph cursors Causes the graph cursor to jump one screen width in either direction Memory handling Record Time or frequency domain Select spectral weighting network Tabulation of results Generate printouts Instrument mode Calibration Battery status Display backlight on off er EE EN Pro INx Norsonic yl OLR ENTER 5 STOP RECALL Y YO PAUSE CONT J P SETUP ABC TORE START DEF Go GHI JKL MNO Era Em Cea PQRS TUV WXYZ Croo Jw ca CAL M3 0 Barr as
222. se IMP or noise NOS e The Excitation time Ex time indicates number of seconds for the noise excitation For measuring reverberation with noise excitation the generator must be set to OFF and synchronisation to ON in order to allow the generator to be switched on and off correctly 89 90 Chapter 20 Compensation and correction Compensation and correction General Sometimes the accuracy of a measurement can be increased if the measurement is corrected or compen sated for other known effects Nor140 has the ability to make corrections related to e Use of windscreen e Measurement of random incidence sound or diffuse sound fields Measurement of low levels Option 18 Use of windscreen A microphone windscreen is a useful device for reduc ing the noise created around the microphone in windy conditions The windscreen is also useful for protect ing the microphone from mechanical impacts and from dust However the application of a windscreen will slightly modify the frequency response of the instru ment To correct for this effect and retain the specifica tion the windscreen correction has to be switched on while the windscreen is mounted Instrument menu Correction Random OFF Windscr Preamp OFF S noise OFF 1 Corr par Big w 4 The windscreen correction is adapted to windscreen Nor1451 The nominal correction for the windscreen correction network is shown in section for specifica
223. setup 58 Storing the acquired data 36 Synchro 65 Swept Sine 129 Synchro 65 T Table 41 Presenting the L t as a table 41 Technical specifications 151 AC out 164 Calibration 154 Conformance testing 165 Diffraction around the instrument casing 160 Digital inputs 162 Digital outputs 162 Environmental conditions 164 Frequency weightings 153 Highpass filter 152 Indication range 154 Level detector 153 Level distribution 153 Measurement range 152 Microphone input socket 152 Power supply 156 Preamplifier attenuation 158 Range for C weighted peak levels 156 Range for measurement of A weighted levels 155 Range for measurement of C weighted levels 155 SD card 164 Self noise levels 154 Sensitivity for magnetic fields 165 Sensitivity for vibration 165 Serial I O 162 Signal output 162 Type of instrument 151 USB interface 164 Warm up time 164 Windscreen 157 Windscreen correction 157 Time 13 Time constant 21 Instruments with multiple time constants 21 Time profile 5 37 Selecting which functions to log 42 Trigger 77 Clock trigger 78 External trigger 79 Level above trigger 79 Manual trigger 78 82 Setting the trigger condition 78 U Units 54 How values are indicated 54 USB interface 70 164 V Velocity 149 Virtual Instrument 73 W W marker 47 Warm up time 164 Windscreen 90 157 Windscreen correction 157 Workload 8 Z Z weighting 21 e NN Norsonic Declaration of Conformity We Norson
224. soon as the level in the specified network or filter band is above a specified threshold In this way a noise event may initiate a measurement The duration and time resolution of the measurement are set as usual The selected main time constant F S or I is used for the level triggering function Move the field cursor to the field Lvl above as shown on the figure and press 1 for selecting the threshold A menu as shown on the right is displayed The field below Threshld indicates the sound pres sure level needed for triggering Modify the value by using the INC and DEC key on the right side of the display or key in a numeric value followed by pressing ENTER When the required level is set move the field cur sor to the field below Freg netw Select the required frequency band or network by using the INC and DEC key on the right side of the display The networks Norsonic Nor140 Instruction Manual may be selected by scrolling above the highest fre quency band Press ENTER repeatedly until the main measure ment display appears For making a measurement press the START key A Wait indicator D will be shown in the display instead of the Run indica tor As soon as the level comes above the threshold the measurement is automatically started If you set the repeat measurement function Press SETUP gt 1 gt 1 the instrument will start a new meas urement after the first is finished and wait for the trigg
225. splay is shown adjacent to picture of the keyboard for the instrument You can operate the in strument as usual by pointing on the appropriate key with the PC mouse and click with the left hand mouse button If you have more instrument connect select the wanted unit in the menu Connections You may store a digital copy of screen by pressing Snapshot The setup for the picture format and where to store the picture is found in the File menu The fig ure below shows the setup The screen picture may be stored as Bitmap bmp Jpeg or Tiff The Tiff format is reversed white text on black background Snapshot setup File format File name bmp C Automatic generate new name C jpg C Always use specified name C tiff reverse video Specify name for each picture Start index zi Filename Save in C Documents and Settings Ole Herman Bjor My Documents NN aj Signal input and output Signal input The socket for signal to measure is the normal micro phone input socket of the Lemo type See the section Technical specifications for detailed information The socket supply polarisation voltage and power to the preamplifier The signal input is at pin 4 with the ground refer ence on pin 2 Pin 2 is connected to the outer shield for the connector but it is recommended to separate the shield from the signal reference since the instrument has a very low self noise and ground currents can eas ily dest
226. ssei eeeeee esee eene enne nnns nnn annnm nnn 151 Type OF Instr Teribes ssec ort e e eU atra NO Po dept et 151 A alOgUSINPUS Risas rod 151 MICTOPRONE INPUESOCKE E serio sehtaaneuedetts 152 Highpass filters c sete One chm A acne I E 152 Analogtue todigital COrnverslOD 5 hoo ri recreate a 152 Frequency welgHtllgs s oe eue acri eem cese oia ICE EP IN Dee 153 PA eC PET 153 Time weightings and measured functions sssssssssse meme mene 153 Eevel distriBUtlOI sei att t e e uH aO ro ER E re atts m e eee ee 153 Indication Tange zr recti ec d osa 154 SEIEMOISE IOVS Sects ON 154 Fisld Calibration mi A edv Re tee 154 Measurement duration and r solution it ras e OH E OEC og erc i eere 154 TIMINOACCULA PEE 155 Meas rement ange canta 155 ROWErSUPDIY e M D Ac 156 Display tes ee Aes a e a esae te nc en e tri a estre ct e a evecta 156 Key BOar s pr EE 156 Norsonic Nor140 xv Instruction Manual Adjustment ot indicated levels 5 ar recie a 157 A A NN 157 Hide Sica A A ens ees 158 Preariplifl amp battentlatilOn s eese ocn eio PERDE RERO EORR ERAT RIEEEN EE tucertebts edenda 158 Self noise compernsation eee Rt ai 159 Diffraction around the instrument casing ssssssssssseeeeeeemeeme 160 Signal Output Aes oon oem mea I eA EANGE 162 Sena OPOE Mr Em 162 Digital inputs vi cssvesec ad c E 162 Digital OUtpults oes o ee He AN ste Ora tint ede 162 Digital output control lies ur iecore re c Dac eem o ec a PI
227. ssel is closed Measurement of high sound levels When the option 18 for extended measurement range is installed and the microphone normally delivered with the instrument Nor1225 is used the measurement range may be shifted 10 dB upwards This is achieved by lowering the polarisation voltage for the microphone from 200 V to about 70 V The microphone sensitivity will then be reduced by 10 dB and the instrument will be able to measure peak signals up to 150 dB The change in the polarisation voltage will lead to a small change in the frequency response for the mi crophone This change is automatically compensated when the extended measurement range is selected Since this correction is adapted to the microphone Nor1225 the extended measurement feature should not be used with other types of microphones A ES ticular instrument within 2 dB don t use the 9 If you don t know the self noise of your par E optional correction for self noise To activate or de activate the extended measure ment range press SETUP gt 5 An H is displayed in the lower part of the display when extended range is selected Normally a recalibration of the instrument is not needed However it is good practice to check the sen sitivity of the instrument This can easily be done by applying the usual sound calibrator The sound level meter shall indicate the usual level as stated for the calibrator also when the extended measurement range is selecte
228. st Com Increment and decrement a parameter setting Leave a menu putting changes into effect Stop a measurement Pause and resume a measurement Setup menus Start a measurement Select function to be displayed Select time constant F S 1 X Global or A Profile domain Graphical on screen A weighting Absolute time on off Power on off Exit certain menus Calibrating the instrument Calibration is the normal way of ensuring that the sound level meter measures the level with sufficient accuracy To calibrate we need a sound calibrator The use of sound calibrators dates back to the days when it was easier to design a stable sound calibrator than a stable sound level meter Today sound meas uring instruments are in general as stable as sound calibrators However measuring microphones are very delicate devices designed to fulfil very rigid specifica tions This makes them vulnerable and subject to dam age unless proper care is taken One may therefore say that a sound calibrator is just as much a verification of proper operation as it is a device of adjusting the sensitivity of sound measuring instruments The Nor140 is calibrated by means of menus and key pushes there is no need for a screwdriver to turn a potentiometer When to calibrate Calibration of the Nor140 should preferably take place before a measurement session is commenced or whenever required by applicable standards If you know the micropho
229. struction Manual C une Temm ent ou 1 LIT gi a gun iwa sim im riw Fim m Sim m im m 2 Total number of penc s 3 Number of periode before trigger 4 Number of periods after trigger Tra tme QE 6 Measurement effective duration 0 25 T te TA 18 8 2007 07 25 10 20 17 000 59 3 13 S 2007 07 25 10 20 13 2007 07 25 10 20 22 000 23 24 14 2007 07 25 10 20 23 000 505 25 15 2007 07 25 10 20 24 000 454 25 16 2007 07 25 10 20 25 000 28 Fal 17 2007 07 25 10 20 26 000 46 8 28 18 2007 07 25 10 20 27 000 467 29 19 2007 07 25 10 20 28 000 633 30 20 2007 07 25 10 20 29 000 516 31 21 2007 07 25 10 20 30 000 579 2 22 2007 07 25 10 20 31 000 521 3 23 2007 07 25 10 20 32 000 58 9 E 24 2007 07 25 10 20 33 000 487 35 25 2007 07 25 10 20 34 000 435 3 26 2007 07 25 10 20 35 000 518 Eu 27 2007 07 25 10 20 36 000 61 xi 28 2007 07 25 10 20 37 000 672 29 2007 07 25 10 20 30 000 675 y RA mr 46g 7 Ready 73 74 Chapter 14 Transfer of data to a PC Using Virtual Instrument Nor1036 Connect the instrument to the PC and select the se rial or the USB interface as appropriate by pressing SETUP gt 1 gt 2 Start the program Virtual instrument Nor1036 The program will automatically start to look for the instru ment This may take some time The screen below will be shown when the program is running A copy of the instrument di
230. surements with all available global functions and distribution when frequency analysis has been activated Example 3 The memory can hold approximately 12500000 samples of L t when only onefunctionislogged requires the enhanced profile extension This corre sponds to more than 300 hours logging with 0 1 s resolution Example 4 The memory can hold more than 450 000 samples of L t when all 28 functions are logged in pro file requires enhanced profile and multiple time con stants This corresponds to more than 125 hours with a resolution of 1 s 57 58 Chapter 11 Memory handling SD card memory A SD memory card Secure Digital may be used for storing set ups measurement data and sound record ings The card is located at the left side of the instru ment behind the rubber protection Card with memory size up to 8 GB may be used but we recommend us ing card with memory size 2 GB or less as operation on such card will be faster Note Do not use miniSD without a proper adapter Since the card may easily be removed from the instrument and placed in a card reader connected to your PC the SD card is also a convenient device for transfer of data Never remove the card from the instrument during read ing or writing operations Format Always format the SD card in the instrument before first time use Formatting a card is also the fastest way for deleting all data on the card We recommend that you format your card from t
231. t and the class width is 0 2 dB over the entire 130 dB dynamic range always When the frequency mode has been activated the instrument does statistics in every frequency band You may think that storing all these data will require a huge memory and you re absolutely right Therefore we store just eight percentiles Seven of them are fixed and one is user editable Your user editable percentile can be set to anything in the range 0 1 99 9 both extremes included M 7 Missing percentiles There may be percen tiles that fail to produce values in the table This is because you have not measured for a time long enough to provide the necessary number of samples Statistical sampling which should not be confused with the sampling of the analogue to digital conversion takes place 10 times a second For comparison the sampling of the analogue to digital conversion runs at 48 kHz Since the statistical sampling takes place 10 times a second it will take 10 seconds to produce 100 samples You will need at least 100 samples to be able to calculate the 1 percentile Likewise for the 0 1 percentile the minimum time required will be 100 seconds Measurements whose duration is shorter than these minimum limits will not produce percentile values for all possible settings of the percentiles Norsonic Nor140 Instruction Manual Editing the user defined percentile To enable the editing the instrument must display the percentil
232. t for he specified background noise The result is corrected for a stored background noise spectrum If you want to edit the values move the field cursor to the field NCorr and press ENTER The field cursor is automatically placed at the lowest octave band 125 Hz Write in the required level for each octave by using the numeric keyboard An E at the bottom of the display indicates numeric key board second function and that each entry has to terminated by pressing ENTER Move the cursor field to the next frequency by using the cursor buttons be low the display and enter the corresponding level For terminating the edition and returning to the main menu press an additional ENTER The noise corrected val ues are automatically recalculated The correction is done according to the following equation L CUM T Ins 1 t Hrs Ino Iam MC f where is the corrected modulation transfer function for octave band number k and modulation fre quency f MCx 139 140 Chapter 24 Speech Intelligibility by STIPA mk is the measured modulation transfer function as displayed la is the measured intensity in octave band number k Irs is the intensity in octave band number k re lated to the threshold of hearing Ino is the optional intensity in octave band number k corresponding to a specified background noise level If not used this value is zero lam is an intensity in oct
233. t from the previous check it is highly likely that the overall functionality of the measurement chain is constant The procedure for using this Mic Check feature is as follows 1 Perform a normal calibration of the entire instrument by use of an external calibrator see the previous pages in this Chapter 3 for details 2 Press the SETUP gt 1 Instr gt 9 Misc par gt 7 Mic chk key sequence to open the Mic Check menu Place the cursor on the upper field and turn the feature ON by use of the INC or DEC keys 3 If an external device simultaneously should be controlled by the Mic Check feature turn the DO 3 Digital Output line 3 ON in the lower field 4 Exit from the Mic Check menu by pushing the ENTER key four times 5 By pushing the CAL key the Mic Check signal is activated The measured signal is then read in the display The level will be dependent of the actual previous sensitivity calibration as well as the individual preamplifier and microphone in use Normally using the Norsonic Preamplifier Nor1209 and Microphone Nor1225 the level will be approx 90 dB with a 1 2 dB variation from instrument to instrument 6 Push the CAL key again to turn off the Mic Check feature and make the normal measurements 7 At any time both during and after a measurement i e Running or Ended Stopped status the Mic Check feature may be turned on again The level should display the same value as read in point 4 above NO
234. t up by the meas urement duration parameter By using the storing op tion Repeat a new measurement may be started by a new trigger signal after the first is finished The external trigger option may be used for syn chronising more sound level meters An often used trigger function is the threshold trigger which starts a measurement as soon as the noise level exceeds a pre defined level Used in combination with the repeat function and automatic storing of the result the sound level meter may unattended store a number of noise events for later analysis The triggering of sound records are covered in the section Recording the sound Setup menu Trigger menu SETUP Trigger 1 Instrument menu 1 Meas 2 Meas duration 2 R d 3 L t params Recor 4 Fregency mode 5 Level range 6 Trigger T Noise gen 8 Recording 9 Reference tone BIBRWGS BIBRWGS 78 Chapter 16 Trigger Setting the trigger condition When the instrument is installed with the trigger option the Trigger Menu is found in the Setup menu Press SETUP and 6 for Trigger and press 1 for measure ment trigger The first four lines in the menu allow you to select the function for triggering The last line allows you to set the parameters associated with the selected function Use the W cursor keys below the display to select the desired trigger function Press ENTER to confirm the selection Manual trigg
235. tant and the spectral weighting C or Z verted white text on black background weighting see Setting C or Z as spectral weighting net work for more on this also but once they are set the Use the INC and DEC keys to increment or decre instrument will remember these until they are changed ment the current setting of the parameter Alterna to something else tively use the keypad to key in the required value whenever applicable The sign will appear in the lower line of the display whenever the instrument accepts numerical inputs Setting the duration Your instrument may or may not be equipped with the optional extension 6 which is the time profile logging e If you use the numerical keypad be sure to press This affects the look of the measurement duration set ENTER before moving to the next field to alter up menu To read more about optional extensions see This is not needed when you use the INC and The principle of the optional extensions DEC keys How the menu looks with and without the optional extension 6 installed is shown overleaf To leave the menu putting changes into effect press ENTER There is no cancel function available 20 Chapter 4 Simple sound measurements Measurement duration setup menu Meas dur Meas dur Duration Duration 000 00 Em 00 05 HU Resolution 200ms N 150 Mx 75986 AIBRWGS Measurement duration setup menu when time profile optio
236. that the key has to be pressed down for more than one second for switching the in strument OFF On the use of batteries The Nor140 comes with four AA batteries 1 5 V each Battery lifetime is typically 8 12 hours depends on measurement mode and brand of batteries If you switch to lithium batteries the life time will increase to 15 20 hours The use of alkaline or lithium batteries is strongly recommended to avoid leakage Rechargeable batteries may also be used but with reduced operating time Connecting an external DC source 11 16V to the instrument will not charge re chargeable batteries but power the instrument in lieu of the internal batteries The internal calendar clock is powered by the nor mal batteries even when the instrument is switched off A charged capacitor supply the needed current during the time for changing batteries Data is stored in a non volatile memory and need no power for retaining the information No recharging Connecting an external DC source 11 15V to the instrument will not charge rechargeable batteries but power the instrument in lieu of the internal batteries Battery voltage Battery voltage is presented graphically as f t Press the BATT key to produce this display and press again to exit the display The external supply Battery voltage is shown ETS when connected Ey 12 38 Time elapsed else battery voltage dias since battery replacement Combined lr d batter
237. the cables and adaptors and the calibration procedure is thereby more complicated Norsonic Nor140 User Guide than for the ICP type of accelerometers if a vibration ICP type calibrator is not at hand Due to the high impedance of the signal from the transducer the cables will also often be sensitive to vibration However charge sensitive setting for the instrument Just enter the sensitivity for accelerometers often have lower weight and may the accelerometer in volt per unit as a level sensitivity tolerate higher temperatures in dB If you use an ICP type of accelerometer with a known sensitivity it is easy to calculate the required sensitivity Set up for using an ICP or CCP type of accelerometer connected to Nor140 Power to the accelerometer is supplied from the instrument by selecting ICP in the instrument menu as preamplifier Nor1466 N Item BNC BNC Nor1438 Microdot cable supplied with accelerometer uP Nor1270 147 148 Chapter 26 Measuring vibration using Nor140 Set up for using a charge sensitive type of accelerometer connected to Nor140 The charge produced by the accelerometer generates a voltage proportional to the inverse of the capacitance loading the charge generator The capacitance is the sum of the capacitance for the accelerometer and all cables connected to the transducer The microphone preamplifier normally Nor1209 has very high input impedance typically 10 gigaohm and an
238. the charge sensitivity divided by the sum of the capacitances of the accelerometer and the cable with accessories pc E 1 0 549409 950pF 230pF n v s The corresponding level sensitivity will be 0 002542 tate ms 519 dB L 10lg Typical attenuation through the adapter Nor1447 2 and the preamplifier Nor1209 is 0 1 dB Subtract this at tenuation from the level sensitivity E g 52 0 dB Remember to select Standard as preamplifier and set the preamplifier correction and polarization voltage to OFF in the set up menu for the instrument Norsonic Nor140 User Guide Velocity and displacement Vibration is often measured as velocity or displace ment The velocity can be obtained from the accel eration by time integration of the signal In a similar way displacement may be obtained by integrating the acceleration twice No integration is performed in the sound level meter Nor140 However if the vibra tion signal is sinusoidal with frequency f an integration correspond to dividing the acceleration by the angular frequency 2mf This may also be used for more complex signals analysed in 1 3 octave bands or an alysed by the FFT option An example may illustrate how this is done Assume that the vibration level in the 80 Hz band 1 3 octave is assumed is 74 dB or 0 1 ms The exact midband frequency for the 80 Hz filter is 10 79 43 Hz See ISO 8041 The vibration v
239. the intellectual property rights of third parties wherever applicable which would result from such use Norsonic AS reserves the right to amend any of the infor mation given in this manual in order to take account of new developments If you wish to communicate with us please feel welcome Our address is Norsonic AS P O Box 24 N 3421 Lierskogen Norway Find us on the web www norsonic com Tel 47 3285 8900 Fax 47 3285 2208 e mail infoQnorsonic no Copyright O Norsonic AS 2008 All rights reserved Norsonic Nor140 v Instruction Manual Finding the information you need Thank you for choosing Norsonic The Nor140 has been designed to give you many years of safe reliable operation Your approach to the Nor140 documentation de pends on what you want to do and how much you al ready know The Nor140 Instruction Manual has been divided into twentysix chapters plus an index Each chapter provides different information Depending on your re quirements and your familiarity with sound measure ments as such you may find that you use some parts of this manual often and others not at all The very first chapter acquaints you with the Nor140 and describes its features and possibilities This may be a good starting point so that you know more about what to look for and what you maybe should learn more about The next section provides a closer look at the in strument with a presentation of all major parts and the keys
240. the measurement 2nd netw BIBRWGS 21 22 Chapter 4 Simple sound measurements Making a measurement To start a measurement Press the START key The R in the display indicates that a measurement is running To temporarily halt an ongoing measurement Press the PAUSE CONT key To resume a paused measurement Press the PAUSE CONT key again Upon resum ing the instrument will go on measuring until the total measurement time elapsed equals the preset duration Observe that data acquired the ten sec onds immediately preceding the pause will be erased because of the back erase function see below M 20 What can be done to the measured data Data acquired are available for inspection during or after a measurement r Y You may Display the functions measured Display the result table Change the spectral weighting function between A and C or Z weighting Display the eight percentiles and set one of them as you like e Store them for future use To terminate an ongoing measurement Press the STOP key To resume a terminated measurement o resume a terminated measurement press the PAUSE CONT key Upon resuming the instrument will go on measuring until the total measurement time elapsed equals the preset duration When a terminated measurement is resumed the back erase feature see below will not be activated To switch between absolute and relative time To sw
241. the total measurement time elapsed equals the preset dura tion Observe that data acquired the ten seconds immediately preceding the pause will be erased because of the back erase function see below To terminate an ongoing measurement e Press the STOP key To resume a terminated measurement e To resume a terminated measurement press the PAUSE CONT key Upon resuming the instrument will go on measuring until the total measurement time elapsed equals the preset duration When a terminated measurement is resumed the back erase feature see below will not be activated To switch between absolute and relative time e To switch between time elapsed since start of measurement relative time and date time of day absolute time use the ABS t key To display other functions measured e Use the FUNC key For the German speaking markets these functions will include Ludi and T s To switch between sound level meter display and spectrum display e Press the fut key To make the spectrum appear A weighted e Press the A prew key The display will now appear A weighted This is purely a display function and it has no effect whatsoever on the measured or stored data To move the graph cursor about the frequency bands e Use the d and DP keys Use the I4 and DI keys to move to the extreme left and extreme right To adjust the display top scale e f the bar graph fails to match the level measured use the INC and DEC ke
242. this hardware e This wizard helps you install software for USB Serial Converter SLM13x USB Serial Converter SLM13x has not passed Windows Logo testing to verify its rh aa with Windows lt P Tell me why this testing is important If your hardware came with an installation CD 42 or floppy disk insert it now Continuing your installation of this software may impair or destabilize the correct operation of your system either immediately or in the future Microsoft strongly What do you want the wizard to do recommends that you stop this installation now and Install the software automatically Recommended contact the hardware vendor for software that has passed Windows Logo testing Install from a list or specific location advanced Click Next to continue Back Cancel Continue Anyway STOP Installation 3 Switch on the Nor140 select the USB interface by will suggest looking for the driver itself Select the pressing SETUP gt 1 gt 2 Connect the instrument to option no not this time See pictures below Browse the PC and find the driver located on the application CD Drivers USB W2K_XP Some computers will recom mend you not to install the driver The following box will appear Ignore the message and select Continue Anyway in order to install the driver A CLA i Please choose your search and installation options Completing the Found New D Hardware Wizard The wizard has finished installing the sof
243. throom Unfurni sh BiBRWG Norsonic Nor140 Instruction Manual The acoustic losses of the receiving room used in the calculation may be obtained by measurement by recalling measured value or by estimation The instru ment must be equipped with the option for reverbera tion time measurement in order to allow the measure ment option to be used If the optional noise generator is installed it may be used for the excitation otherwise impulse method has to be used To start a measure ment press START when the field cursor is in the field for reverberation time marked T When you move the field cursor to the field Calc result and press ENTER the following functions are calculated for each of the octave bands 125 Hz to 2000 Hz e The normalised level difference Dn e The standardised level difference Dnr The apparent sound reduction index R e The source room level L e The receiver room level Lz e The reverberation index k e The reverberation time T For the values D Dar and R a frequency weighted value according to ISO 717 1 is also calculated together the correction terms C 25 2000 marked as C and Ciis 2000 marked as Cy Pressing the FUNC key repeatedly will display the different functions The weighted values are all rounded to the nearest dB If you want to go back to the calculation menu just press ENTER Press the MODE button if you want to return to nor mal mode of operation
244. tion FFT function Spectrum unit Averaging Number of averages Trigger Input source Dynamic range Zoom 24 kHz 16384 samples 0 682666 sec 8192 frequency lines 6553 will be available after LP anti aliasing filter Pass band ripple 0 03 dB Stop band attenuation 100 dB 0 9600 Hz 1 dB point Af 1 T 1 46 Hz 24000 21 Hanning Auto spectrum dB and EU Engineering units Linear power averaging 1 to 1028571 Manual External Clock Level above Option Microphone socket 120 dB 80 dB displayed Display function C 1 2 4 8 64 146 Chapter 26 Measuring vibration using Nor140 Measuring vibration using the Nor140 Introduction Most sound level meters and sound analysers can be used for vibration measurements even if they do not provide absolute linear units in the display To simplify the description this chaper describes the use of the handheld sound level meter Nor140 for vibration measurement However the described principles also apply to other types of sound level meters Although several transducer principles are commercially available this application note will deal with the accelerometer only simply because it is the transducer type most commonly encountered when measuring vibration levels As the name suggests the accelerometer measures the acceleration it is exposed to and provides an output signal proportional to the instant acceleration The accelerometer nor
245. tions exist for transferring data from the instrument to a personal computer PC The instru ment may be connected to the PC by either a serial cable RS232 or an USB cable USB An alternative will also be to store the data on the SD card and move the card to a PC for loading the data Norsonic sup ply different programs for controlling the instrument and analysis of the measured data Contact your lo cal Norsonic distributor for more information as the number of programs is steadily growing Pin out of the cable Nor1441 the other end is standard RS232 fitting directly into your pc Mini D sub Norsonic Nor140 Instruction Manual Kor Xter 4 3 0 C Documents and Settings Ole Herman Bor My Documents iNersoniciMy Measurements 070723 DER Tavo Tvesee For just reading the data stored in the instrument or on the SD card the program Nor1020 NorXfer is recommended The program is included with the de livery of the sound level meter The program transfers the data from the instrument to a format suitable for WindowsXP The data can be delivered as a text file or as an Excel workbook Included with the instrument is also a PC program Virtual Instrument which allows you to operate the sound level meter Nor140 from the PC and display a copy of the information on the instrument screen on the screen for the PC Combined with a PC projector this is ideal for demonstration and training The connection to the P
246. trument indication to be vibration expressed as m s Memory handling The instrument has a large built in non volatile memory which can hold large amounts of measured data and measurement setups These data can be transferred to a remote PC for further processing and or printed out In addition the data may be stored on a SD card Cards up to 2GB may be used Memory structure The memory structure of the Nor140 is quite similar to that of a PC They both have folders and files How ever simplicity is a keyword in the Nor140 memory handling the folder available for storage has the name of today s date and the files are numbered consecu tively in ascending order as they are stored starting at 0001 A memory structure metaphor wm Today s date File No 9999 3 File No 000 File No 0002 File No 0001 Norsonic Nor140 Instruction Manual Internal memory size The size of the part of the Nor140 internal memory in tended for storage of measured data is approximately 25 megabytes This is a number which says more or less nothing to most people since it reveals nothing of the number of bytes required to store the measured values etc Let us therefore provide a few examples Example 1 The internal memory can hold more than 50 000 global measurements with all available global functions and distribution when frequency analysis has been deactivated Example2 The memory can hold morethan 12 000 global mea
247. tware for 4 The PC will tell you that a new device is found and prompt you for a USB driver to be installed Windows Search for the best driver in these locations Use the cheex boxes below to im at expand the defaul search which inckides local paths and renovable medis The best doves found w be installed Search semovable media floppy CD ROM F Inchide thie location in the search nni IFWOX Xp x Browes C Dorit search vell choose the driver to install Choose this cation to select the device driver from a let M eee ear gears the driver youchoose wil be the best match for your hardware e USB Serial Converter SLM13x Click Finish to close the wizard Chapter 14 Transfer of data to a PC 5 The installation of the USB driver is complete when case you got several Nor140 you must repeat the this picture appears procedure from 5 to 7 Each new Nor140 you connect to the PC will get its own COM port 6 The PC will prompt you for a Port Driver to be in stalled Repeat the procedure described in point 4 8 Use the Device manager to find the COM port The and 5 above device manager can be found under control panel system and hardware Click on the device manager 7 The Nor140 has now been routed to a fixed COM port Icon Expand the Ports Com tree See picture below on your PC This COM port must be used each time The COM port number can be found here you connect this particular instrument
248. uits you better In the enhanced mode the instrument logs the time profile of the same functions as with the global e SPL The Instantaneous Sound Pressure Level e Luax The Maximum Sound Pressure Level e Lun The Minimum Sound Pressure Level e leq The Integrated Equivalent SPL e Le The Sound Exposure Level e Leak The Maximum Peak Level If you then add the option 5 parallel time constants you may set up the instrument to log any combination of functions and time constants for example the SPL with S time constant and the maximum SPL with F time constant simultaneously Enhanced time resolution as well The enhanced profile has a time resolution which can be from 50 ms and upwards in 25 ms steps in 1 second steps above 1 second time resolution so beware unless you want to create a busy day for yourself there will easily be quite a lot of data generated so avoid more details than strictly needed Multispectral measurements The Nor140 functionality can be expanded to include multispectral measurements This extension takes the instrument s time profile capabilities to new heights by allowing complete spectra to be logged as a function of time Source coding Have you ever made a measurement where you later found out that you desperately need to know what caused the level to be what it turned out to be Enter source coding With the enhanced profile op tion you may tag or code sources as they happen A one digit code
249. uld decrease with increasing modulation frequen cy Constant or slightly reducing values in a column indicate the presence of noise Large reductions indi cate that reverberation is the main effect Values that first reduce and then increase with increasing modu lation frequency indicate the presence of periodic or strong reflections which may produce an over opti mistic conclusion It is recommended that if this effect is detected it should be reported with the results and an estimated correction applied Limitations of the STIPA method The STIPA method should not be used for those public address systems that a introduce frequency shifts or multiplication frequency b include vocoders i e LPC CELP RELP etc C have a background noise that is impulsive d introduce non linear distortion components strong Norsonic Nor140 Instruction Manual If d applies or possibly applies the full STI method should be used instead or used to verify the results obtained by the STIPA method Using Excel for further calculations An Excel workbook STIPA Calc is delivered with the STIPA option The workbook allows you to correct your readings for different speech levels and levels of back ground noise similar to the corrections available in the instrument Recall the stored results from an earlier measure ment Press the button TBL to display the speech level and enter the levels into the cells for the spee
250. upted noise method and the integrated impulse re sponse method Nor140 apply the integrated impulse response method but the interrupted noise method may also be used if option 10 internal noise genera tor is additionally installed The integrated impulse re sponse method is often called Schroeder method after Dr Manfred Schroeder who disclosed the theoretical relations between this and the interrupted noise meth od The reverberation time is extracted from the decay by the use of a least mean square fit algorithm The decay curve measured with the interrupted noise method is the result of a statistical process and averaging several decay curves or reverberation times c measured at one microphone loudspeaker position is mandatory in order to obtain a representative value The integrated impulse response of a room is a deter ministic function and not prone to statistical deviations so no averaging is necessary However for many ap plications you still need spatial averaging Calculating the reverberation time Measurement with noise excitation Measuring the reverberation time by using abrupted noise is often referred to as the classical method The noise source is switched on for a time sufficient to ob tain a steady level The source is thereafter switched off and the decay of the sound in the room is ob served Without loss of generality the time for switch ing the noise off may be set to t O A plot of the sound
251. y pressing RECALL However no profile will be shown from recalled files since the profile is not stored with the result 101 102 Chapter 22 Sound power Sound Power About sound power measurements Sound power may be calculated from sound pressure levels using the Nor140 equipped with option 15 The method is described in ISO 3746 acoustics determi nation of sound power levels of noise sources survey method and requires measurements of the A weighted sound pressure level at four or more positions located on a hypothetical measurement surface of an area S which envelopes the source To facilitate the location of the microphone positions on the measurement surface a hypothetical reference box shall be defined When defining the dimensions of this box elements protruding from the source which are not significant radiators of sound energy may be disregarded The measurement surface on which the microphone positions lie envelopes the source as well as the refer ence box The location of the source under test the meas urement surface and the microphone positions are defined by a coordinate system with the horizontal axes xand y in the ground plane parallel to the length and width of the reference box The characteristic dimension d is shown in the Fig on the next page One of the following two shapes shall be used for the measurement surface a a rectangular parallelepiped whose sides are parallel to those
252. y voltage MM bi as an f t gt 3 BIBRWGS V Low Voltage Situations When the combined battery voltage drops below 3 9 V a battery low indicator appears in the display and the instrument will start to shut itself off Any ongoing measurement will be terminated and stored in a direc tory called BATLOW Memory contents are retained without the use of electrical power flash memory Upon installing fresh batteries the instrument will at start up ask the operator for the confirmation to store the previous measurement in the normal measurement directory If the instrument is connected to an external DC source the external source voltage will be displayed EV Should the external power fail during a measurement without any internal batteries installed or the installed batteries have no power left the instrument will be turned off immediately without storing the ongoing measurement However as the Norsonic Nor140 Instruction Manual instrument automatically make a backup storage every 2 minutes the last file stored will include the correct results except for maximum the 2 last minutes prior to the power failure Upon return of the external power the instrument will automatically start to measure as if the START key had been pressed If powered from internal batteries and left un attended and unoperated the Nor140 will switch itself off after ten minutes However this does not apply if the instrument is measuring
253. ys to alter the display top scale setting To switch between the spectral weighting functions e Use the NETW key to switch between A weighted and C or Z weighted or the A weighted and the C A Z A weighted functions To produce the results in tabulated form e Press TBL to produce a result table Resuming an ended measurement Assume that you have set up the instrument to measure for 5 minutes and that you start the measurement After 5 minutes the measurement will end since the meas urement time elapsed equals the preset duration The measurement has now ended successfully as opposed to if you press the stop key to forcefully terminate an ongoing measurement If you now press the PAUSE CONT key the instrument will resume the measurement and go on Norsonic Nor140 Instruction Manual measuring for another 5 minutes so that the total meas urement time assumes 10 minutes e twice the initial setting lf you do this again the total measurement time will be 15 minutes i e three times the initial setting and so on This way of prolonging a measurement will not activate the back erase feature The back erase feature When you press the PAUSE CONT key during an ongoing measurement the instrument will temporarily halt the measurement Pressing the key again will cause the instrument to resume the measurement while at the same time erasing the data acquired during the last ten seconds immediately preceding the pause

Nor-140 User Manual - Campbell Associates

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