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Nor-118 User Manual - Campbell Associates

1. Clock Clock The date and time setting Y M D menu Press setup gt 1 Instr gt 01 10 13 3 Clock to produce this menu H M S Lee27 Norsonic Nor118 13 User Guide The front panel keys of the Nor118 Cursor keys to navigate in the men us and to operate the graph cursors EJ NN Norsonic Causes the graph cursor to jump one screenwidth in either direction Power on off Display backlight on off Memory handling Increment and decrement a parameter setting gt 0 Select function to be displayed Select time constant Cy Select spectral weighting network Siart a measurement x Global or A Profile domain Time or frequency domain Pause and resume a measurement a C JA Stop a measurement t fe 3 E Absolute time on off Setup menus Tabulation of results Battery status Instrument mode pe Fw ojo Graphical on screen a weightin p ila Leave a menu putting changes into effect i T Calibration men Generate printouts 3 i i Exit certain menus 14 Chapter 3 Calibration Calibrating the instrument Oon 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 measuring in
2. oct 6 3 Hz to 250 Hz 0 dB option 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 1 kHz In order to compensate for effects due to diffraction around the microphone we recommend adjusting the sound level meter to indicate 113 8 dB diffuse correction off If other types of calibrators or electrostatic actuators are used for the calibration we recommend adjusting the sound level meter to indicate the following levels referred to the sound pressure acting on the diaphragm of the microphone diffuse correction off 1 kHz 0 2 dB 4 kHz 0 8 dB 125 Hz 0 0 dB 250 Hz 0 0 dB 8 kHz 2 8 dB Freq Level Measurement duration and resolution The total time period for a measurement global period designated amp may be set from 1 second up to 100 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 Norsonic Nor118 User Guide an option the time resolution may be set in an additional range from 100 millisecond and upwards to 1 second in steps of 25 millisecond Total range for measurement of A weighted levels The linear operating range is identical to the total range Frequency 31 5 Hz 1 kHz 4kHz 8kHz 12 5 kHz Upper le
3. INSTRUCTION MANUAL INSTRUMENT SOFTWARE VERSION 1 2 A sound level meter with built in real time analyser capabilities Parallel octave filters are standard optional in some markets but the impressive list of optional extensions include sound power calculations third octave filters and statistics in every frequency band multispectrum and reverberation time measurements The instrument logs level vs time optional and when it is equipped with multiple time constants and the enhanced profile extension a multitude of functions is logged si multaneously The 120dB dynamic range eliminates the need for range setting A large memory and high speed data transfer rates complete our user friendliest solution to date NOF W NN Norsonic Nor118 User Guide November 2002 Edition Editor Gustav Bernhard Ese Dipl Ing Text and Layout Gustav Bernhard Ese Production Notes This manual was created electronically on the Microsoft Windows 2000 platform using Adobe InDesign Artwork was made using Adobe PhotoShop and Macromedia FreeHand Proofs were made on Epson Stylus Color 3000 using Adobe PressReady HP LaserJet 4050PS and 4MV PostScript printers RIP and final printout were made at Allkopi H vik Norway We used Adobe Caslon Pro open type and Helvetica typefaces in this User Guide Norsonic is a registered trademark of Norsonic AS All other brand or product names are trademarks or registered trademarks of t
4. product control noise mapping and more But you don t need to attend the measurement ses sions all the time In fact the Nor118 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 in a separate file but all files are stored in the same directory which has the name of today s date In this way the instrument will measure the periods you need And do not forget that 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 stor ing 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 experi ence 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 slightly earlier to provide time for store and restart By sacrificing a little at the end of a measurement the synchronisation with the time of day is retained a feature important to many of our customers The principle of optional extension
5. vides the keywords you need 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
6. 1dB 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 con sidered 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 25 V to 5 25 V to avoid harming 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 If not rede fined by remote commands DO 3 will go high when the calibration mode is enabled Microphone heating The microphone preamplifier Nor1206 contains a 225 ohm resistor suitable for heating the microphone preamplifier A floating voltage supply in the range 0 12 V may be con nected between pin 10 and 11 As the lines will be in direct contact with the signal ground on the preamplifier utmost care has to be taken for not influencing the measurement of low levels Data storage Measured data is stored in the internal memory of the sound level meter The memory is of the flash type retaining the information without battery supply Approximately 5 Mbyte is available for the data storage This corresponds to one of the following examples e More than 10000 global measurement with all avail able global functions and distribution w
7. acoustic environment requirements Calculating the A The value of the mean acoustic absorption coefficient a is estimated by using the above table The value of A is then given in m by A ax S in which S is the total area of the surface of the test room walls ceil ing and floor in m For the purpose of the survey method the method described here the measurement surface is considered to lie outside the near field if the measurement distance from the source under test is equal to or greater than 0 15 m Specific requirements Examples of permitted reflecting planes outdoors include compacted earth artificial surfaces such as concrete or sealed asphalt while for indoor measurements the reflecting plane is usually the floor Take care to ensure that the reflecting surface does not radiate any appreciable sound energy due to vibration The reflecting surface must be larger than the projection of the measurement surface on it The sound absorption coefficient details on this are given in the 180354 of the reflecting plane should preferably be less than 0 1 over the frequency range of interest This requirement is usually fulfilled when outdoor measurements are made over concrete sealed asphalt or stone surfaces For reflecting planes with higher sound absorption coefficient e g grass or snow covered ground the measurement distance shall not exceed 1m For indoor measurements wooden and tile floors are also permitt
8. sound level meter However the methods described in Iso 3746 a weighted measurements involve a tedious calculation procedure before you end up with the single figure you need to be able characterise your measurement object So why not let the Nor118 take care of this for you Just specify the measurement surface type hemisphere or parallelepiped its dimensions and the location of your measurement object on the floor against a hard reflect ing wall or in a corner apply the correction factors and start your measurement Ihe sound power will then be calculated and displayed in tabulated form available as optional retrofit later Noise monitoring and mapping The large memory and the time synchronising capabilities of the Nor118 makes it well suited as a front end in noise monitoring systems outdoors for community noise as well as indoors in workshops etc The high dynamic range 120 dB makes the setup easy and ensures reliable measurements in all situations The Norsonic product range contains a wide range of equipment and accessories for use with noise monitoring and measurements We supply enclosures for perma nent monitoring installations environmental cases for semi permanent installations microphones for applica tions in tough environments cables modems weather stations and post processing software A detailed pres entation of this is available in a separate leaflet and on Www norsonic com Real time freque
9. 1Ec 61672 1 CLASS I GROUP X measuring exponential time weighted levels integrating averaging levels and sound exposure levels If 14 octave band or octave band filters are installed the instrument complies with IEC 61260 CLASS I IEC 60651 TYPE I and IEC 60804 TYPE I Analogue inputs Number of channels 1 Input connector 7 pin LEMo connector for Norsonic microphone systems LEMO ECG 1B 307 CLL Preamplifier supply voltage 15 volt max 3 mA Polarisation voltage 0 V and 200 V selectable Maximum input signal 11 V peak Input impedance More than 100kohm less than 650 pF Measurement range 0 3 mV to 7 V RMS in one range corresponding to 10dB to 137dB with a microphone sensitivity of 50 mV Pa The maximum peak value 10 V 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 Heater supply Ref pin no 7 2 GND signal reference 3 Polarisation voltage selectable 0 1 V 200 2 V short circuit current lt 1mA impedance 2 MQ 4 Signal input 5 15 0 5 V preamplifier supply voltage max 3 mA Connected to pin 6 6 15 V Connected to pin 5 7 15 0 5 volt preamp supply voltage max 3 mA Housing is GND instrument casing Highpass filter The input section is equipped with a highpass filter to reduce noise from wind or other sources with frequencies below the frequency r
10. ALL DATA RESET CANCEL Clearing folders or the entire memory To clear a folder Select it using the cursor keys and press enter You will now be prompted to select between clearing the CUR DIR i e the current folder or directory ALL DATA in the entire memory or to RESET the entire memory The option CANCEL is also included to avoid unintended erasures If so use EXIT to leave the menu You cannot delete the file that you are displaying There fore in order to clear this file press Ex1T before you enter the CLEAR menu N Norsonic Nor118 75 User Guide Keeping track of the measurement mode the file was stored in The differ ent modes are indicated in the file list as follows Recall OEE 00017 010831 00027 ae 011016 All file names i e file num 011018 bers have a letter as suffix This letter indicates the measure ment mode F means frequency analysis but no profile means that the file contains a simple global measurement but no frequency analysis and no profile means a multispectrum measurement means a measurement made in sound power mode means a reverberation time measurement means a profile measurement with or without a frequency analysis The uppermost text line in the display which file has been retrieved The little R denotes Recalled just like S denotes Stored 011014 0001R 39 SETUP 0002R g0 00 12 55 00 12 55 a 011019 i 0
11. acoustic environment requirements A area outdoors or an ordinary room will provide a suitable environment if the requirements given in the ANNEX A of the 1so 3746 and briefly outlined here are satisfied When measuring in accordance with the ISO 3746 the envi ronmental correction factor K is obtained from this graph by entering the abscissa with the appropriate value of A S 10 A S 50 100 300 Norsonic Nor118 User Guide 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 undisturbed by reflections from nearby objects and the room bounda ries and b outside the near field of the sound source under test Oo Description of Room 0 05 Nearly empty room smooth hard walls made concrete brick plaster or tile 0 1 Partly empty room room with smooth walls 0 15 Room with furniture rectangular machinery or industrial room O02 Irregularly shaped room with furniture irregu larly 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 65 66 Chapter 12 Sound power
12. acquired data e Press the store key The display will show the folder and file number Allaspects of the memory handling are discussed in detail in Memory handling Printing out the results By connecting a printer to the Rs232 interface the results can be output to a printer This is treated in detail in Making hardcopies NV Frequency analysis A AN OPTIONAL EXTENSION you may have your Nor118 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 8 16 000 Hz for the octave band filters and 6 3 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 measurements Setting up The frequency range is fixed and cannot be changed by the user Bearing in mind that the dynamic range of the Nor118 is no less than 120 dB and that the instrument measures a fixed set of functions which cannot be altered by you there is not much left to set up before the instru ment is ready to make a frequency analysis Actually the setup procedure boils down to specifying the measurement duration the time constant to be used and the use of c or z weighting ensuring that the fre quency mode has been activated and in case of extension 3 present specifying the filter ba
13. attenuation 16 Preamplifier attenuation compensating for 88 98 Appendix 1 Index Preferred value characteristic distance parallelepiped sound power 62 Prepolarised microphones and polarisation voltage 11 Preventing access to keyboard keyboard lockout 79 Printers supported 76 Printouts defin ing functions to print 77 examples of printouts 77 generating 76 printers supported 76 setting up for 76 starting a printout 77 Profile function activation menu See Enhanced profile Profile measurements basic version 35 enhanced version 40 including multispectrum 46 switching between time and spectrum multispectrum 47 PWR 81 Q Question mark appearing in table reverberation time 57 R Random response correction activating 86 RD 81 Ready mode returning to after a measurement 21 Recalling stored setups and data 73 Rectangular parallelepiped calculating the characteristic dimension 59 Reference box 58 Reference box requirements sound power 58 Reference Level Range 92 Reference Sound Pressure Level 92 Relative time 6 Relative vs absolute time in global measurements 20 Repeat storage mode 79 Reset the entire memory 75 Resolution of basic time profile measurements 38 of enhanced time profile measurements 41 better than 1 second 42 Resume an ended measurement frequency analysis 29 global measurements 21 a paused global measurement 20 Retrieving stored setups and data 73 Reverberation time backwards integrati
14. below What can be done to the measured S data Data acquired are available for inspection during or after a measurement You may e Display the functions measured e Display the result table e Change the spectral weighting function between a and c or z weighting e Display the eight percentiles and set one of them as you like e Store them for future use 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 again Upon resuming the instrument will go on measuring until the total measurement time elapsed equals the preset duration When a terminated meas urement 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 measure ment relative time and date time of day absolute time use the aBs t key To display other functions measured e Use the runc key For the German speaking markets these functions will include LeqI and TMax5 To adjust the display top scale Ifthe bar graph fails to match the level measured use the INC and pec keys the vertical arrow keys to the right of the display 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
15. cartridge see High levels in the Technical specifications for details Norsonic Nor118 27 User Guide Menu for the activation of the frequency mode Freq mode Press sETuP gt 1 gt 4 Mode to produce this Parallel menu Bandwidth 1 1 oct Activating the frequency mode In order to enable frequency analysis the frequency mode must be activated Activating frequency mode 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 4 As long as the frequency mode has been z activated frequency analysis will be made during every measurement This means that the instrument will combine a traditional sound level meter measurement and a real time frequency analysis in octaves or third octaves Whether the instrument is set to show the spectrum or the classic sound level meter display will not affect the meas urement in any way Likewise going between the two display modes during a measurement has no effect on the measurement either 28 Chapter 5 Frequency analysis Switching to displaying the spectrum Having activated the frequency mode and left the menu just press the f lt ot key to display the level vs frequency and press again to return to the other display Since no measurement has been made the only function produc ing frequency band bar graphs will be the spt with the selected time constant If you press the Func key this w
16. conformance testing is 4 x1 6 V 6 4V Electromagnetic Compatibility When the instrument is tested for conformance to electromagnetic compatibility requirements the instrument should be in the measure ment mode as this normally will generate the highest levels of emissions The highest susceptibility is normally observed when the display faces the principal direction of propagation for the electromagnetic field N Index Symbols p appearing in table reverberation time 57 A A weighted spectrum 28 A weighted levels total range for measurements 85 Absolute time 6 Absolute vs relative time in global frequency analysis 28 in global measurements 20 AC out frequency response 90 gain accuracy 90 max output voltage 90 mini sub D pinout 81 output impedance 90 Adding markers 44 Adjusting the date 12 the time of day 12 Analogue output 90 Analogue to digital conversion specifications 83 ANSI S1 4 1997 type 1 random incidence correction 86 Attenuation compensating for preamplifier attenuation 16 88 Automated storage of measured data 78 B Back erase and statistics 4 and time profile mode 38 detailed presentation of the principles behind 21 Background noise reverberation time 53 Norsonic Nor118 93 User Guide sound power 68 Backwards integration 53 Basic time profile measurements 35 and multiple time constants 39 and pause 39 functions measured 39 including multispectrum 46 Batteries recommended types
17. correction values see the Field calibration side bar overleaf for more on this Mount the calibrator onto the sound level meter 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 the documentation accompanying your sound calibrator Set the sensitivity To set the sensitivity correctly use the INc and pec keys the and the keys located Norsonic Nor118 15 User Guide The sound calibrator should be mounted onto the micro phone as shown here Do not use the exit key to leave the calibration menu see text for details Calis 140 sens F Lev 1138 dB Use these keys to adjust the sensitivity or use the numercial keypad to key in the sensitivity 16 Chapter 3 Calibration q Field calibration The recommended Z sound calibrator for verification of the sound level meter Nor118 is the Norsonic Nor1251 with a nominal sound pressure level of 114 0 dB 1kHz In order to compensate for diffraction effects around the microphone we recommend adjusting the sound level meter to indicate 113 8 dB diffuse correction off Ifother types of calibrators or electrostatic actua tors are to be used for the calibration we recom mend adjusting the sound level meter to indicate the following levels referred to the sound pressure level acting on the
18. dubious value s using the Ca J CY keys to see values of other frequency bands 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 e Press STOP or PAUSE CONT In both cases the instrument will return to READY mode The instrument will measure for 10 seconds and count down to 0 to indicate how much is left of the measurement The acquired results are then presented as 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 reverberation time measured is too short compared to the minimum reverberation time stated in the table a few pages back a question mark will be shown to the right of the value Likewise the question mark will appear if the back ground noise level is too high Allin all the question mark tells you that the measurement is not reliable However it does not tell you why it is so Overload occurring during the impulse decay capture is indicated by an OL appearing above the result table In addition no reverberation time will be calculated and the table will reflect this Saving the measurement While still displaying the result table the acquired data may easily be stored To store a reverbera tion time measurement
19. for your profile measurements 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 Nor118 41 User Guide 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 Setting the resolution To 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 good as 100 ms See text for details Meas dur Duration 00 00 Resolution Here the reso 125ms lution is set to 125ms N 40 Mx 707174 42 Chapter 7 Enhanced time profile measurements No back erase in profile pause mode The resumption 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
20. made with F time constant and the class width is 0 2 dB over the entire 120 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 Norsonic Nor118 User Guide Your user editable percentile can be set to anything in the range 0 1 99 9 both extremes included The procedure is explained overleaf Data measured but not yet stored may be subject to changes in the user defined percentile This means that as long as you have not stored the acquired data you may change the percentile as many times as you want but once the data are stored any changing of the user editable percentile is no longer possible The percentiles table sequence 13 00 05 30 010728 Ka 22 39 24 w ISPL 30 ae No 83 0 50 Y 0 05 A Leq 37 9 F Max 39 5 F Min 37 3 LE 44 9 Peak 53 5 I Leq 46 4 F Tmx5 39 5 F SPL Units without statistics Units equipped with statistics 24 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 X 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 us
21. measure decays of 20 or 30dB and then extrapolate the results to 60dB In the Nor118 a 20dB range is used and the figures are then normalised to 60dB Reverberation times measured this way are often denoted T20 Backward integration The instrument employs what is called the INTEGRATED IMPULSE RESPONSE METHOD Or SCHROEDER METHOD to calculate the decay The excitation signal used is by nature a stochastic signal and repeated excitation will yield different decay curves each time you do this However if you do this a large number of times the decays will cluster around a mean value Dr Manfred Schroeder has shown that this value can be obtained using a single decay measurement only Two restrictions apply here impulse excitation must be used hence noise source excitation is out of the question and the decay must be integrated backwards with respect to the time The Nor118 does this by default in fact you cannot switch the feature off This means that you will imme diately obtain the expected value in the statistical sense of the word of the decay Observe though that this will Norsonic Nor118 User Guide not free you from spatial averaging You must always pay respect to the fact that local variations exist in all rooms The position chosen for the microphone is not necessarily fully representative for the room You should always make several measurements and average them see later in this chapter for more on this Le
22. measures the full fre quency range every time Given the high dynamic range 120 dB which eliminates the need for adjusting the gain there is very little to set up before a frequency analysis can be made successfully Norsonic Nor118 User Guide The measured functions are also available in tabulated 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 Frequency band statistics Adding option 4 to your Nor118 will expand your frequency analysis to even cal culate 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 2dB to ensure sufficient resolution and the results are presented in the form of eight percentiles 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 store the measurement in the instrument s memory only the selected percentiles will be available to keep the amount of data lower The fixed percentiles The fixed perc
23. 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 OFF Preamp OFF Snoise OFF l Corr par Navigate in the menu using the arrow keys and use INC or DEC to activate deactivate the Random setting Activated Random setting is indicated by an R in the lower line of the display to the right of the display 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 established press ENTER to leave the menu Do not use exit to leave the menu The Exit key will be interpreted as the sign whenever the Nor118 expects numerical inputs indicated by the sign appearing in the lower line of the display Hence pressing EXIT will not cause the instrument to leave the menu but instead insert the sign Typically you will now press ENTER since EXIT didn t work The result is that you have inserted 0 as the sensitivity setting and consequently your measurements will all be wrong To fix this press the cAL key again and enter 26 dB as the sensitivity value before you calibrate the unit again W The dB value corresponds to the sensitiv ity level of the microphone cartridge dB re
24. naren una Aer r i 71 Memory handling Monor aO os sesasesp ogee AA E E E E T P Momor ooi ea E T A E I 72 1 10g cl 74 eee ee er etre ee errr rer eee eee 72 ON INO AIM a SU IGE a o E S 73 SHOU A TC ASU e a P O A T E T 73 FREESE storedsetup and dassies E L3 Clearing files and Tolders in the MEMO ninnan 74 S E tale log A A E A A 74 Tearing Tolders or thie entire MEMO annoia i Making hardcopies IE Sat eel CODE e ner ere E E OT 76 RS WO Ch ON UO UES e E A E 76 PPE O UE NG AS UE A E E E at dnsateaactice 77 Noise monitoring Noise PO MLO LI ac socdeancenacnciaassepssnpictviedssacesaceanenceedbaleysseensssusarssabeseenoaceaneays 78 Automated storage of measured datassa 78 Vac E e E nat ee eee nme ene eee eee eee T 78 RV IOS E E A E T E 79 Norsonic Nor118 xi User Guide RS MIO EMS SiO tes sci caro atc E ed iatapettanccnecaives 80 RD EG SC CUI AG eG corse pasate ete sie stipes e E E A E 80 Chapter 17 Transfer of data to a PC TA eS et OR UE OBC etch cree ss cance ede ace sete ose T 81 Chapter 18 Technical specifications Py FO THIS eA VE A E E E A 82 Passe lkoYea 0 Ceasho U1 ce renee peer T E E E eee ree eee ee eee 82 Microphone DUE SOCKET asprin E R O 83 a A E A E N A E A A 83 Analopue tadik MLCOnVei O sosser E eer aren Re 83 E E T E E E E T EE 83 BEV EO sa sag rasanse ance A E E 83 Time weightings and measured TUNCt iON 5 ccoccsqceseucecencasecasusssceneesVesennsecesees 84 Lec S elec eo E mere rernrer en errr nner tet Te
25. press the store key whilst still displaying the reverberation time results Norsonic Nor118 57 User Guide To store the acquired data e Press STORE to save the measurement The measure ment will be stored in a folder bearing today s date as its name and the file name will be the first free number Existing files will not be over written If the folder did not exist it will be created when you store the data Recalling a stored measurement A stored measurement is retrieved as any other measure ment stored The values will be presented in a table identi cal to the result table See the chapter Memory handling for a discussion of storage and retrieval of measured data Making another measurement If you want to make another measurement you may do this with or without storing the one you just did To make another measurement e While in the result table press the start key You will now be prompted to either store the acquired data by pressing STORE or start another measurement directly by pressing START again Leaving the table returning to READY mode You may leave the table to go back to ready mode without having to start another measurement first This may be the case if the trigger settings needs adjustment To leave the table e Press the Ex1T key to leave the table You will now be prompted to either store the acquired data by pressing STORE or exit directly by pressing EXIT again NM 58 Ch
26. profile mode and the f lt t key to enter the the time axis frequency domain 3 Use the lt and the gt keys to move the cursor one 2 Use the and the V keys repeatedly if needed to screenwidth along the time axis in either direction reach the moment in time required EE A gE Z A 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 ft 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 X words the vertical cursor keys are used to move in the other domain than h the one displayed to move in time when displaying the spectrum q and to move in frequency when display a time profile To see the level vs time the profile graph of another frequency band 1 Make sure the display shows a time profile level vs time Use the foot key if needed 2 Use the and the 4 keys repeatedly if needed to move to another 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 UA key to enter global mode 2 Use the foot key to go b
27. recommended Sensitivity for vibration If the instrument is used under strong vibrational condi tions 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 perpendicular to the diaphragm Typical values are 55 dB to 65 dB for acceleration values of 1 ms 2 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 28 mm Width 74 mm Length excl microphone preamplifier 234 mm Length incl microphone preamplifier 365 mm Weight incl batteries 630 91 92 Chapter 18 Technical specifications Information for conformance testing Reference Sound Pressure Level 114 0 dB re 20 Pa 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 bat tery voltage for
28. resolution 0 1 dB based on interpolation Indication range The calibration of the instrument allows microphones with sensitivity in the range 84 dB to 15 9 dB relative 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 26 0dB corresponding to a microphone sensitivity of 50mV Pa For voltage input the level OdB then corre sponds to 1mV Typical values for the self noise are 5 dB 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 Nor1206 averaged over 30 s of measurement time Spectral weighting functions a weighted 13 dB c weighted 15 dB z weighted 25 dB Filter bands oct 6 3 Hz to 250 Hz 10 dB option oct 315 Hz to 20 kHz 5 dB option Noise measured with Nor1225 microphone and preampli fier Nor1206 averaged over 30 s of measurement time Spectral weighting functions A weighted 18 dB C weighted 22 dB Z weighted 30 dB Filter bands oct 6 3 Hz to 250 Hz 15 dB option 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
29. see Simple sound measurements for details 40 Chapter 7 Enhanced time profile measurements Enhanced time pro file measurements HE OPTIONAL EXTENSION 7 enhanced time profile 2 Navigate in the menu as usual and use the 1nc and lets you select the functions to be measured as a func DEC keys to activate the functions required for your tion of time Select from A weighted functions as well as task Deactivate those that you won t need A 1 means c or Z weighted even a weighted peak Furthermore activated and a 0 means deactivated enhanced profile opens up for the use of source coding see Adding markers for details Apart from this there is 3 Both the a weighted and the c or z weighted func no difference between basic and enhanced time profile tions are accessible from within this menu Use the mode NETW key to switch between a and c or z weighted which is set up in the 2nd network menu see Simple sound measurements for more on this Selecting which functions to log Functions to log setup menu We always recommend that you keep the number of LCC pAr WCC pat functions to measure as small as possible This helps to FST F maintain the overview and keeps the amount of memory a ni A R a spent low Although it may be tempting to measure eve A pir 111 A nies 1 rything do not forget that you are going to review the A Min 000 A Min 0 acquired data afterwards How much time are you willing Saat O
30. the display the Inc and DEc keys to increment or decrement the current setting of the parameter Alternatively use the keypad to key in the required value whenever applicable The sign will appear in the lower line of the display whenever the instru ment accepts numerical inputs e If you use the NUMERICAL KEYPAD be sure to press ENTER before moving to the next field to alter This is not needed when you use the 1Nc and DEC keys e To leave the menu putting changes into effect press ENTER e There is no CANCEL function available 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 1Nc and pec 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 parameter fields again Press ENTER to leave the menu putting changes into effect i e setting the time and date N Microphone cartridge Screw only finger tight e Default cartridge is designed for 200V polarisa tion voltage but this can be switched off Microphone preamplifier To fasten preamplifer screw it on here Preamplifier socket Front plate Instrument body Display a3 je Multifunction socket External power input socket Keyboard 9080 080 080 8 BAL 00o OBL 200 Aa if ji ij f Battery compartment a
31. the entire 120 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 Instruments configured for the German speaking markets will measure Leal with I time constant and TMAxs5 with F time constant in addition see below The functions are available sequentially To display a certain function press the Func key repeatedly until the function appears The sequence is as follows Leq gt Lmax R T SPL Lmin hee Lpeak q _ L oe Accessible during measurement only not after Norsonic Nor118 31 User Guide The LPEAK and TMAXs are not accessible Z when the spectrum is displayed Units configured for the German speaking markets If also equipped with m and TMAX5 the sequence is as follows press FUNC key repeatedly R Leq gt Lmax gt Lmin q TMAX5 Leql Lpeak L Accessible during measurement only not after Units equipped with multiple time constants Units equipped with multiple time constants will measure SPL LMAX and LMIN with all three time constants F s 1 employed simultaneously In sound level meter display mode use the runc key to produce the function and then Tc key to display values with th
32. the relevant noise test code Mic positions one reflecting plane Each plane of the measurement surface shall be considered on its own and so subdivided that the result is the smallest possible number of equal sized rectangular 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 Nor118 63 User Guide More than one reflecting plane For a source installed adjacent to more than one reflect ing plane reference shall be made to the figures shown on this page spread for the purpose of defining a suitable measurement surface Microphone positions are as shown in the Figs N Procedure for fixing the specified microphone positions where a side of the measurement surface exceeds 3d lt 3d lt 3d O O i i lt 3d lt 3d lt 3d 64 Chapter 11 About sound power measurements Example of a measurement surface and microphone posi tions for a small machine Reference box Q9 Microphone position Microphone placement with four microphones for floor standing ap pliances placed against a wall and an example of microphone placement for a larger machine Details on the microphone posi tioning can be found in the ISO 3746 and three microphones for floor standing appliances placed in a corner Sound power
33. the reverberation time of the room If your Nor118 is equipped with the optional extension 9 REVERBERATION TIME MEASUREMENTS you may use this to calculate the absorption as follows Koa 10log 1 4S A dB Koa 10log 1 4 SxT 0 163xV dB based on an actual reverberation time measurement Norsonic Nor118 User Guide Test room qualification requirements For the measurement surface in a test room to be satisfac tory for measurements in accordance with the require ments of 180 3746 the ratio of the sound absorption area A to the area S of the measurement surface shall be equal to or greater than 1 that is A S2 gt 1 The larger the ratio A S is the better If you cannot meet this requirement a new measure ment 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 4 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 Nv 67 68 Chapter 13 Measuring the sound power Measuring the sound power TT 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 any test object in accordance with 1s0 3746 and related Standards This means that when equipped with a Norl18 you may test the Lw of new products for the European C labelling in the p
34. there should be no need to either since the only things to set up are the trigger frequency band and the trigger level threshold To make a reverberation time measurement e Press the start key and generate the impulse While the instrument waits for the trigger condition to be fulfilled a W wartine 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 Frequency bands above 10kHz are not measured Although the instru ment has filters covering the frequency range up to 20kHz expressed as filter band centre frequency reverberation time calculations are made up to 10 kHz only Those above are shown in the table as well but no values are presented The reverberation times measured are presented tabulated and are all in seconds as shown here Values missing are shown R like this Frequency bands not measured will look like oct T20 this The same applies to anh a frequency bands where no 630Hz 0 238 value was obtainable sree oe If the background noise level 1 25k Hz 0 18 is too high or the calculated 1 6k Hz 0 23 ae eter gt Ok HZ 0 19 reverberation time is shorter 2 5k Hz 0 19 than the limit see side bar F Minimum reverberation times for more on this a question mark appears next to the Navigate in the table by
35. will assign this marker to the current period plus all consecutive peri ods 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 Norsonic Nor118 45 User Guide The keys to use The keys used to enter the markers are caL marker 1 PRINT marker 2 ExIT marker 3 and ENTER marker 4 since these keys are the lower most keys of the front panel and thus easy to reach during a measurement None of these keys are used for other things during a measure ment either Other markers inserted by the instrument As discussed in the side bar No back erase in profile mode a few pages back the 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 srop key and later resume the measurement by pressing PAUSE CONT an s marker will be added to the period within which the pausE conrT key was pressed i e we mark out the first period after resump Marker 1 has been inserted tion a P and S markers have priority The marker 4 is a oggle marker i e once activated it will assign a marker to every period occurring until it is deac 10 000 a tivated again The keys used to insert markers What happens if mark
36. windscreen Nor1451 The windscreen correction has to be switched on to obtain the stated specifications The nominal correction for the windscreen correction network is shown in the figure below Norsonic Nor118 User Guide 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 Nc and Dec keys Do the same to deac tivate Windscreen correction activated is indicated by a W in the lower line of the display Windscreen correction Frequency Hz Correction 05 12 55 011025 Random 18 35 16 Windscr ON Preamp ON F SPL 40 s nolse ON c 57 0 l Corr par A 37 2 RWGS RWGS High levels As an option the instrument may measure levels 10 dB higher than stated as the standard range The extended measurement range is obtained by reducing the sensitiv ity of the microphone through the application of a lower polarisation voltage When this option is selected the 87 88 Chapter 18 Technical specifications polarisation voltage is lowered from 200V to about 70 V A correction network is applied automatically to compensate for the change in frequency response of the microphone due to the lower polarisation voltage The nominal response for the high level correction network is shown in the figure below Correctio
37. 0 O i Beats a to devote to that Setting up the functions to log 7 1 To gain access to the profile function activation menu press SETUP gt 3 L T PAR This menu looks as shown to the right Setup menu with multiple time constant option left and without the multiple time constant option right Units with multiple time constants installed may include the time constant setting in the setup see the Fig below left Functions like Leq Lmax Lmin and Lppax are measured during each period The spi however is sampled at the 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 meas urement 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 seETUP gt 1 gt 8 Functions to be printed are denoted by a 1 The time constant cannot be set from 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
38. 18 User Guide The measurement surface can be either a hemisphere or a parallelepiped In addition you may choose between different loca tions of your test object i e on the floor up against a hard reflecting wall or in a corner Sur face The background noise measurement display Although the Nor118 lets you measure the back ground noise level in up to 40 positions the back ground noise level will in most situations vary so little from one microphone position to another that it is for most cases suffi cient to measure the back ground noise level for one typical microphone position the calculated Lwa value switch to global frequency measurements mode make a measurement and press the A PREV has been made key The spectrum will now appear a weighted on the results are the screen purely a display function the measured presented like data are not affected and the frequency band s contributing the most should now be easy to spot 4 If you need to know which of the fre quency bands that contribute the most to After a suc Use next and Although only 8 previous microphone positions t between are shown there iia as are further pages so that a total of 40 microphone positions can be covered Use the key cessful set of this upon press ing the TBL key atm The results can also be orinted out Turn to Making hardcopies for a sample 70 Chapter 13 Mea
39. 32 navigation rules 32 setting C or Z weighting 27 setting the display topscale 29 the sequence functions appear in 31 time constant setting 26 Frequency range of Z weighting network 19 Frequency response AC out 90 analogue output 90 Frequency weightings technical specifications 83 Front panel keys 13 Functions available in basic version 3 defining functions to print 77 displaying in global frequency analysis 28 displaying in global measurements 20 displaying in enhanced profile 43 measured 84 sequence of appearance when multiple time constants frequency analysis 31 the sequence they appear in frequency analysis 31 to log in enhanced time profile 40 G Gain accuracy AC out 90 analogue output 90 Global measurements absolute vs relative time 20 activating frequency mode 27 and statistics 18 and units configured for German speaking markets 22 frequency analysis 31 back erase feature in detail 21 displaying functions measured 20 frequency analysis 28 simple sound measurement 20 the sequence they appear in 21 Norsonic Nor118 95 User Guide frequency analysis 31 displaying the percentiles 23 frequency analysis 30 displaying the spectrally weighted functions 20 displaying the spectrum 28 display tables 20 using the other spectral weighting function 20 duration setting 18 duration setting for frequency analysis 25 editing the user defined percentile 24 frequency analysis 33 features available after a measure
40. 55 E 18 08 21 p Leq 40 FSPL 40 c 56 4 c 56 7 A 42 0 a A 41 6 0 0 dB dB 76 Chapter 15 Making hardcopies Making hardcopies EASURED DATA CAN BE OUTPUT to a printer for documentation The instrument s print drivers support the following printer types HP THINKJET Class of printers HP DESKJET Class of printers DICONIX range of printers e Most numerical printers The range of printers commercially available is an ever changing issue herefore what was true by the time of design of the printer drivers used in Nor118 may not be Press sETup gt 1 gt 2 to produce this menu TO Print Port Dil Baud rate ELSZzoo Printer THINKJET Language ENGLISH true the day you read this Output from the Nor118 is purely numerical hence almost any numerical printer should be able to produce the output text on the paper 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 experi ments with the setup and your printer to find the driver that produces the best looking printouts Setting up for printouts The setup for printouts is made in the O Print menu To set up for printing 1 Press setup gt 1 Instr gt 2 IO Print 2 Set the SERIAL INTERFACE PORT to ON set it to OFF when not used to save batteries set a baud rate your printer c
41. 8 or later if that suits 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 Lmax The Maximum Sound Pressure Level Lyin The Minimum Sound Pressure Level ie The Integrated Equivalent SPL Lp The Sound Exposure Level Lprax 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 pro file has a time resolution which can be from 100 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 Norsonic Nor118 User Guide day for yourself there will easily be quite a lot of data generated so avoid more details than strictly needed Multispectral measurements The Nor118 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 option you
42. 86 typical life time 86 use and care 10 voltage 92 voltage vs time 11 Baud rate serial I O port 90 BT product 54 C C weighted levels total range for measurements 85 C weighted peak levels measurement range for 86 94 Appendix 1 Index Calibration 14 and diffuse correction 16 how to do 14 of free field microphones 15 of free field microphones at other frequencies than 1000Hz 16 setting the sensitivity 15 when to calibrate 14 Calibrator See Sound calibrator Cartridges and polarisation voltage 11 Characteristic dimension 58 calculating for rectangular parallelepipeds sound power 59 Class width 4 84 Clearing files and folders in the memory 74 folders or the entire memory 75 Clearing a single file memory handling 74 Codes 9 Conformance testing 92 Copy to Prnt Xfer 41 Crestfactor capability technical specifications 84 D Data storage technical specifications 90 Date adjusting 12 Deleting files and folders in the memory 74 folders or the entire memory 75 DI 1 81 DI 2 81 Diconix 76 Diffraction around the instrument casing 89 Diffuse correction and calibration 16 setting 16 Digital inputs input impedance 90 Digital outputs output impedance 90 DIN45657 84 Display of functions measured in the sequence they appear in global measurements 21 of the basic time profile 39 in enhanced profile 43 returning to live display after a measurement 21 technical specifications 86 Displaying functions measure
43. Declaration of Conformity does not affect our warranty obligations Tranby November 2001 D ap A a 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 21010 E Beginning v Some experie nce v Intermediate v Advanced Tutorial v How to v Reference NN Norsonic P O Box 24 N 3421 Lierskogen Norway Tel 47 3285 8900 Fax 47 3285 2208 info norsonic com Find us on the World Wide Web http www norsonic com Mh Completely Revised Expanded amp Up to Date Your approach to the Nor118 documentation depends on what you want to do and how much you already know The User Documentation has been designed to help you get more benefits from all the analyser s features in less time than ever before Need to start by understanding the ideas behind the analyser s design Read the Introducing Nor118 section This section outlines in just a few pages all the funda mental features of the analyser Need to get knowledge about a certain topic The manual provides detailed informa tion in extensive articles Lots of tips and hints included Need to know the correct procedure for setting the sound level meter up The order of appearance of the topics reflects the recommended sequence Looking for a certain topic but don t know where to find it The extensive index pro
44. L t when all 28 functions are logged in profile requires enhanced profile and multiple time constants This corresponds to more than 25 hours with a resolution of 1s 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 To store a measurement setup e Set up the instrument as required and press STORE without making a measurement Setups are stored ina separate folder called SETUP This is setup No 2 stored in this instrument S for stored Ve SETUP 0002S 39 GULLA 011018 ae i 23 08 44 lt This measurement has been FSPL 49 stored as file No 1 in today s 5 4 9 folder S for stored E C A 43 2 po 011016 0001S gn dB a oos Leq 40 c 53 9 A 45 7 x 7 Norsonic Nor118 User Guide All settings are stored but upon recall of a setup all set tings affecting the hardware is not read back into the instrument Hardware settings such as baud rate pream plifer 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 To store the data e Press the sTorE key after a measurement The data will now be st
45. Microphone positions hemispherical surface sound power 60 parallelepiped surface sound power 62 Microphone Reference point and direction 92 Minimum reverberation times possible 54 Mini D sub plug pinout 81 Modems of conventional type cable needed 81 Mode indicator of stored files 75 Multiple time constants in basic time profile 39 in enhanced profile 41 Multispectrum measurements 46 switching between global and profile 49 N Noise monitoring automated storage of measured data 78 things to consider 78 Nor1206 84 Nor1225 84 Nor1441 cable 81 Nor1489 cable for GSM modems 81 Nor1490 cable 81 Number of microphones sound power 68 O OL appearing in table reverberation time 57 Options available 9 checking options installed 9 Norsonic Nor118 97 User Guide the principles behind 8 Output impedance AC out 90 analogue output 90 P Parallelepiped surface 62 Pause and basic time profile 36 a global frequency analysis 28 a simple sound measurement 20 Pause marker 38 Percentiles defining your own 23 frequency analysis 33 displaying frequency analysis 30 missing values 18 setting the user defined 24 the percentiles table sequence in global mode 23 Polarisation voltage and prepolarised cartridges 11 reducing to enable measurements of high levels 87 setting the voltage 11 Power See also sound power requirements to external 86 socket for external power 86 Power supply 86 Preamplifer compensating for its
46. NALYSER 2 Chapter 1 Introducing the Nor118 Introducing the sound level meter Nor118 N INPUT WE VE HEARD OVER AND OVER AGAIN is that We like your Norl16 sound level meter very much indeed but quite a few of us would like to see that you add filters to it Point taken But instead of just adding filters we did a complete redesign of the hardware Apart from the microphone cartridge and the preamplifier there is now digital technology everywhere We added a new display with higher resolution and backlight we added a larger memory we added high speed data transfer up to 115200 baud we added the real time octave band and third octave band filters and we extended the dynamic range One of the first things you ll notice when using the Nor118 is that there is no need to set the measurement range simple and convenient We ve added new functionality but the old Nor116 had a lot features worth retaining So we decided to keep the markers the parallel time constants the electronic level recorder and the sound power calculations To add further flexibility the Nor118 accepts prepo larised microphone cartridges as well as the conventional microphone cartridges designed for 200 V polarisation voltage There is more to this than just providing you with the option of using your existing stock of microphone cartridges by reducing the polarisation voltage to 70 V optional extension the instrument will be able to
47. a weighted functions To produce the results in tabulated form e Press TBL to produce a result table See Displaying the result tables for more on this 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 measurement time elapsed equals the preset duration The measure ment 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 measuring for another 5 minutes so that the total measurement time assumes Io minutes i 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 way of prolonging a measurement will not activate the back erase feature see below for more on this The back erase feature When you press the pausE contT key during an ongo ing 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 measure men
48. an handle be sure to use the same setting in the printer experiment with the printer type see above and unless you re in need of printouts with German 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 To set which functions to print out 1 Press sETUP gt 1 gt 8 2 Use the cursor keys to navigate and the 1nc 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 allows 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 To start a printout 1 Set up everything as required 2 Press the PRINT key For level and frequency analysis measurements the entire data set will be printed out For profile measurements the printout will contain the periods from the present cursor position till the end of the time record How to print the level the profile and the frequency spectrum e You decide
49. ange for measurements Filter type 3rd order HP filter 3dB at 4Hz Butter worth response Norsonic Nor118 83 User Guide Analogue to digital conversion The analogue input signal is converted to a digital signal by a multirange sigma delta converter with an effective sampling frequency of 48 kHz The anti aliasing 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 octave band levels may be measured simultaneously if options providing these weightings are installed Filters 1 4 octave filters 8 16 16000 Hz class 1 digital 11r filters base 10 system IEC 61260 octave filters 6 3 8 10 20000 Hz class 1 digital 11r 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 01dB for indicated levels in the range 9 99 to 99 99 dB Highpass filter frequency response Frequency Response of HP Filter Level dB 100 110 frequency Hz 84 Chapter 18 Technical specifications Crest factor capability The crest factor is only limited 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 in
50. apter 11 About sound power measurements About sound power measurements Sox POWER MAY BE CALCULATED from sound pres sure levels using the Nor118 The method is described in 1803476 ACOUSTICS DETERMINATION 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 ele ments 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 reference box The location of the source under test the measurement surface and the microphone positions are defined by a coordinate system with the horizontal axes x and 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 arectangular parallelepiped whose sides are parallel to those of the reference box in this case the measurement distance d is the distance between the measurement surface and the reference box b ahemispherical surface or partial
51. ast square fit Let us now consider the reverberation decay as a set of experimentally observed points The method of LEAST SQUARE FIT is then used to find the line of best fit that one for which the sum of squares of the deviations between the line and the observed points is a minimum This method is used in the Nor118 to obtain a line representing the reverberation time see Fig below Important terminology Level dB The decay curve is exposed to A Peak level of impulse backwards emt e integration not shown here l Ae a N Mee smoother then N The line obtained by yl least square fit is used to determine the reverberation time The distance 4 to the noise N floor N 53 54 Chapter 10 Reverberation time measurements When measuring the reverberation time we specify E rere ailonuiince a trigger level above which a sound level occurring is assumed to be the excitation impulse The instrument Pigeon Tienes Sia Gos captures the decay looks for the peak value and starts sec sec the calculation 5 dB below this value Then it measures 50 Hz 1 01 the time it takes for sound to decay by 20dB by means 63Hz 0 83 0 43 of the LEAST SQUARE FIT METHOD and multiplies the 80 Hz 0 68 value found by 3 If the distance to the noise floor is more 100Hz age than 10 dB and if the reverberation times are more than a specified set of minimum values and finally if no overload pestis ae e has occurred the values are
52. asurements are made in the same way as ordinary time profile measurements The only differ ence lies in the fact that the multispectrum measurements 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 X lt gt A key to enter profile mode 2 Use the fst 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 f lt ot key 2 Use the lt and the gt keys to move the cursor along the frequency axis 3 Use the lt and the gt 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 48 Chapter 9 Multispectrum measurements To move the cursor along the time profile axis To see the spectrum of another moment in time 1 Make sure the display shows the time profile level vs 1 Make sure the instrument is in profile mode and that time If needed use the fot key the spectrum is displayed a A displayed in the upper left corner of the display If not press the XA key 2 Use the lt and the gt keys to move the cursor along to enter
53. at the 1nSttu Mieit is22cecccactesdvaecctesceswesiciesbincicaccunesenecezes 10 Via PG Se OL BAe E A snistsusteanaseasaeules 10 Patey VORA e yS TC acts chh sts case nes Games deed eee teat E A 11 DEL LINO the POlAr sal AS sson ass arises snctansnictesetee onidapesunisideotgeseeanribues 11 DCE Ta Ee Tie AI GAG E E E E T 12 Calibrating the instrument Calibrate TGS UG 1G ea E seossvedeets 14 VV ING EO GALS ACE E A 14 No Heed To adjust the Tull Seale Serto iesirea 14 Ray 1S OULU Cle Ca P nie iaeanaien 14 Chapter 4 Chapter 5 Norsonic Nor118 User Guide Simple sound measurements DTP le SOUT MIC ASU eT CG aaas ER 17 RS CTO ES e ath E E N E 17 S E E E E E E E A 18 Instruments withtime protile ahedres 19 ea Ne eCo ci E78 a T 19 lnstruments with multiple time Constant sossroissrssiecseresssssin reesi 19 Whultiple time constants and Statist iCS asneiras en aee 19 Cor Las Spe Ci fal Weis Mine TEE WON K siirron e 19 Makine a TMGASUT MICIE sarei arinin srira oara ri Es EE 20 Resuming an ended WC AST E 11 CE ssp csutdistantonniacaisiiasiseas sandsnoainautdastieaurbincaiess 21 Noles ae lel eles center 10 cree eee ore ee ee ee eee E 21 Displaying the uncthons MCAS UTC segipena 21 Depla aoctherem ag lo Loc nin A re ctr ererer errr 22 otausnes displaying the percentiles enssaissnneniraiei 23 Die play ime He Per Contes TABI sess ita scoasshdvienisontescnea n E 24 So EE INS A HU a E enact E E 24 Poa O e cic U1 cane rerrner ern ere rere eee S
54. ax or the Ln appears in the display first Measurement duration SETUP 1 Instr Time profile option 6 2 eee installed 3 L t par 4 Freq mod 6 Lvl range Meas dur Meas dur P Duration Duration 00 05 00 05 Resolution 00 00 05 l i N66 Time profile not tect FA hSaeS installed Setting C or Z as spectral weighting network The Nor118 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 these functions has been that none of them are properly defined in any standard The z spectral weighting circuitry is flat within at least 16 Hz to 16 kHz in the Nor118 it extends far beyond that and it is well defined in an upcoming standard FDIs IEC 61672 The Nor118 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 4 2ND NETW and navigate in the 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 spectrum in the display Going to measure very high levels As an optional extension the Nor118 is able to meas ure very high sound pressure levels without changing the microphone
55. ber of microphones 68 measurements 68 measurement surface defining for the Nor118 71 microphone positions hemispherical surface 60 parallelepiped surface 62 rectangular parallelepiped 58 reference box 58 reference box requirements 58 results of a measurement 71 survey method 66 approximate method 66 test report requirements 58 Source coding See Markers Spatial averaging and backwards integration method 53 Spectral weightings technical specifications 83 Spectral weighting function selecting Z or C in global mode 19 Zor C 3 Spectrum A weighted 28 displayed as a table 32 displaying the 28 logging the spectrum vs time 46 making it appear A weighted 28 Starting a global measurement 20 including frequency analysis 28 Statistics and multiple time constants 19 back erase 4 Norsonic Nor118 99 User Guide editing the user defined percentile 24 frequency analysis 33 fixed percentiles 5 missing percentiles 18 percentiles table sequence in global mode 23 range of the user defined percentile in global mode 23 sampling frequency 18 user defined percentile 24 Stop and then resume in enhanced time profile 42 Storage modes 78 Storing a measurement 73 a measurement setup 73 measured data automatically 78 Survey method approximate method sound power 66 sound power 66 Synchro an example 79 storage mode 78 Synchro mode 8 y T20 53 Table available tables with basic time profile 37 39 Appendix 1 Index available ta
56. ble Nor1441 the other end is standard rs232 fit ting directly into your Pc fN D sub Bs Norsonic Nor118 User Guide Pin Signal Dir Remarks 1 DO 1 Out Digital output DO 2 Out Digital output 3 DO 3 Out Digital output for calibration only high calibration ON 4 DTR Out RS232 5 TD Out RS232 6 PWR Out 3 3V max 10 mA 7 GND ref digital lines 8 DI 1 In Digital input 9 DI 2 In Digital input 10 HEAT1 In Power mic heating 11 HEATO In Ref for HEAT 1 12 DSR In RS232 13 RD In RS232 14 GND ref analogue signal 15 AC out Out Analogue output Housing GND Instrument casing 81 82 Chapter 18 Technical specifications Technical specifications Ux STATED OTHERWISE the specifications are for the complete sound level meter Nor118 equipped with microphone type Norl225 and microphone preamplifier type Norl206 Values are based on the sensitivity set to the nominal value for the microphone 26 0 dB corre sponding 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 pressure level or frequency is reduced The definition of terms is based on 1Ec 61672 1 In draft form at the time of printing The options included in the basic instrument may vary Please check with your local supplier for the latest information Type of instrument Sound level meter
57. bles with enhanced time profile 43 available tables with frequency analysis 32 available tables with multispectrum measurements 49 available tables with reverberation time measurements 56 displaying using the other spectral weighting function 23 display for global measurements 20 in global mode 22 leaving table in reverberation time mode 57 sound power measurement results 71 TD 81 Technical specifications 82 Terminate and then resume a frequency analysis 28 and then resume a global measurement 20 a global frequency analysis 28 a global sound measurement 20 Test report requirements sound power 58 Time adjusting 12 Time frequency switching multispectrum 47 Time axis scaling absolute vs relative time 6 Time constant frequency analysis 26 multiple and enhanced profile 41 multiple and frequency analysis 31 multiple and global mode 19 setting in enhanced mode 41 setting in global mode 19 statistics and multiple time constants 19 Time constants technical specifications 84 Time profile measurements and pause 36 basic version 35 consider the resolution 36 display of the basic profile 36 enhanced profile 40 See also Enhanced profile logging the spectrum vs time 46 basic profile 46 enhanced profile 46 making 38 multispectrum measurements 46 pause marker 38 setting duration in basic version 38 setting the resolution of basic profile measurements 38 stop marker 38 tables available in basic version 37 tabulated 39 Time r
58. ce the steady state condition is reached the level wil increase no further If you now switch off the sound source the sound will take some time to decay The time it takes for the sound pressure to decay by 60 dB is called the reverberation time Excitation signals Above we talked about having a steady sound source in a room when measuring the reverberation time However we may just as well use an impulse as excitation source This impulse may be generated by a pistol an exploding paper bag or any other impulsive sound source capable of creating enough sound energy in the frequency range we need Speaking of paper bags the primary application of paper bags will normally be to produce low frequency energy in a frequency range where pistols tend to have too little acoustic energy On the other hand the high frequency energy produced by an exploding paper bag is not impressive so you cannot rely on a paper bag alone Impulse excitation eliminates the need for dragging heavy loudspeaker amplifier combinations with you In addition you will be able to rely on battery operation alone with no need for mains voltage This will increase your field operation capabilities How we measure the reverberation time Although the reverberation time is defined as the time it takes for the sound level in a room to decay by 60dB the presence of background noise will indeed make this difficult to measure The normal circumvention is then to
59. d Norsonic Nor118 71 User Guide 3 Finally key in the acoustic environment correction K2 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 Nor118 will display the final Lwa To see the sound power calculation results e Press the TBL key e In addition to the overall results the impulsive noise values the Lppaxc or Lpraxz level and the noise direc tivity of the test object for all microphone 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 measurement 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 examples together with the calculation procedure for the determi nation of the environmental correction factor K2 which has been repeated from the previous chapter for your convenience NV 72 Chapter 14 Memory handling Memory handling HE INSTRUMENT HAS A LARGE built in non volatile memory which can hold large amounts of measured data and measurement setups These data can be printed out and or transferred to a remote pc for further process ing Memory
60. d For comparison the sampling of the analogue to dig ital 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 are shorter than these minimum limits will not produce percentile values for all pos sible settings of the percentiles To produce the measurement duration setup menu e Press sETuP gt 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 meas urement 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 Bais and function displayed Preset duration Spectral Measurement weighting running networks Datum lower applied end of bar Measured graph values Going to measure very high levels As an optional extension the Nor118 is able 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 th
61. d in global measurements 20 in enhanced profile 43 Display topscale setting 20 DO 1 81 DO 2 81 DO 3 81 DSR 81 DTR 81 Duration of basic time profile measurements 38 E Electret microphones and polarisation voltage setting 11 Electromagnetic Compatibility 92 Electronic level recorder electronic version See Time profile measurements Enhanced profile 40 functions measured 7 40 setting up 40 including multispectrum 46 measuring in 43 multiple time constants 41 tabulated 43 time constant setting 41 time resolution 7 better than 1 second 42 setting 41 Environmental conditions technical specifications 91 Environmental correction factor sound power 66 Extensions See Options F Field calibration 85 File naming conventions memory handling 72 Filter bands 85 Folder structure memory handling 72 Free field microphones setting calibration level correctly 15 Frequency analysis activating frequency mode 27 and statistics 5 26 and time profile 26 and units configured for German speaking markets 31 displaying the percentiles 30 displaying the spectrum 28 duration of global measurements 25 editing the user defined percentile 33 frequency cursor moving back and forth 29 frequency range for fractional octave measurements 4 functions measured 5 global measurement 25 logging the spectrum vs time 46 setting up for 46 making a global 28 making the spectrum appear A weighted 28 multispectral measurements 46 result tables
62. d 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 An example of the table is shown to the left Use COC keys to move the cursor up and down but only after the measurement has ended N 43 44 Chapter 8 Adding markers to a measurement Adding markers to a measurement AVE 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 What were these impulses caused by et 39 6 Mk Pei S EET D DTN ba amp S z gt 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 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 a measurement 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
63. 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 exhibit 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 4 seconds to be exact to give room for data storage and housekeeping so that the measurement will start exactly on the hour Available storage modes The Nor118 will always operate in one of four available storage modes These are e Manuau 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 termination regardless of the reason for termination irrespective 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 measurement setup and duration Repeat applies 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 stor ing the acquired data Therefore a slight delay typ
64. e of the test room walls ceiling and floor in m l Calculating the S a Hemisphere S 2nr Parallelepiped S 4 ab bc ca vy i Z ol a st d b d Ei k d aea 7 I are the ee dimensions of the B rectangular refer ence parallelepiped lows the exactly the same procedures 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 measure the background noise level for one typical microphone position To toggle between the measurement control display and the background noise measurement control 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 corresponding 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 c for test objects placed against a WALL or in a CORNER The selected surface is also indicated by a simple dia gram 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 displaye
65. e different time constants In the frequency spectrum display mode the functions will appear in the following sequence a Leq Lmaxr Luinr p L Lmaxs Loins SPL o p Accessible during measurement only not after eo Luinrt q _ I max 1 Leql 32 Chapter 5 Frequency analysis Sound level meter display mode P y 00 05 30 wS 010728 axe 223024 Z 83 0 a sS TBL P 50 Units not configured for the German speaking markets will have tables without Leq Leql and Tmx5 values down Spectrum m display mode AF SPL 77 0 TBL dE Displaying the result tables To switch between A and C or Z weighted values use the NETW key ISPL 90 Use the vertical cursor keys to scroll the centre frequency up and mMm Use the Func key to select function 0 55 4 oct Lea 63Hz 52 2 125Hz 45 6 250 Hz 44 1 500Hz 43 2 pe 2 0k Hz 47 5 4 0kHz 41 9 8 0k Hz 36 2 16 0k Hz 2r 2 dE E 0 05 CF L 0 3 L 1 0 L 5 0 57 5 aoodocoocc L10 0 57 1 SERE Statistics is optional Use the vertical cur sor keys to change the frequency band 0 55 noct 1 0kHz Leq 46 0 F Max 66 1 FMin 27 6 LE 63 5 F SPL 0 5 4 oct 1 0kHz LAUSE te 2 b T0 69 3 L 5 0 53 0 eee eee eee L10 0 46 4 a o o L50 0 30 0 L90 0 28 7 L95 0 28 4 L 99 0 27 9 dE Statistic
66. e time profile installed you should set the resolution to the same value as the dura tion to avoid that the instrument starts 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 spi the Lmax and the Luin Measurements but neither the Leg the Lg nor the Lprax makes 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 Lm 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 multiple time constants will always employ all three time constants F s and 1 for all measurements The time constants apply to the spt the Lmax and the Lm functions Leg Lpzax and Lg do not make use of time constants However units configured for German speaking markets will also measure the Lear The presence of multiple time constants eliminates the need for setup of the time constant Norsonic Nor118 User Guide Multiple time constants and statistics Observe that the statistics buffers optional extension will be based on sampling using time constant F This canno
67. ed 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 4 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 1803746 the environmental correction factor K is given by K 10lg 1 4 S 4 dB where A is the equivalent sound absorption area in the room at 1 kHz in m S is the measurement surface area in m Environmental corrections as a function of 4 5 are illus trated on the previous page Approximate method The mean sound absorption coefficient a of the surface of the room may be estimated using the table shown on the next page The value 4 is given in m by the formula A as 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 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
68. el 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 Nor118 39 User Guide 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 measure ment An example of the table is shown in a side bar on the preceding pages Use COC keys to move the cursor up and down but only after the measurement has ended w q Combining multiple time constants with the basic time profile Combin ing multiple time constants with basic time profile gives you no extra features in the profile logging The function subject to the use of time constants the maximum spt will be logged with the time constant used in the normal display mode by the time you start the measurement 130 00 05 30 010728 22 39 24 ISPL 90 A oo Z 83 0 50 In the above example this will be the 1 time constant Note that statistics if applicable will still make use of the f time constant and that the other functions logged in the profile part of the measurement make no use of time constants The global part of the measurement will utilise the multiple time constant as any global measurement will
69. en the 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 measure ment Will you need a 1 second resolution for 24 hours It s going to be a lot of information to go through afterwards No absolute rules or guidelines can be given since there are so many different applications and require ments However we address the issue to remind you of the need to consider it when setting up for profile measurements The time profile display The A indicates profile global is indicated by a x a Spectral weight Graph cursor ja ng function j Use COC applied to the keys to move graph the cursor along 0 the graph This 1 04 RA featureisnot A Leq 37 Measurement available during Mk running a measurement Value at cursor s position Pause and profile Ay 30 1 49 W A Leq 42 8 Mk PD dB J Here the instrument is in pause mode Global acquisition 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 Display top scale Norson
70. en absolute and relative time e To switch between time elapsed since start of measure ment relative time and date time of day absolute time use the aBs t key To display other functions measured e Use the runc key For the German speaking markets these functions will include LeqI and TMax5 To switch between sound level meter display and spec trum display e Press the foot 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 data To move the graph cursor about the frequency bands e Use the lt amp gt keys Use the x amp keys to move to the extreme left and extreme right To adjust the display top scale Ifthe bar graph fails to match the level measured use the INC and DEC keys the vertical arrow keys to the right of the display 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 measurement time elapsed equals the p
71. ency analysis in octaves 8 Hz to 16 kHz or third octaves 6 3 Hz to 20 kHz 3 4 Chapter 1 Introducing the Nor118 The functions measured are the equivalent level the maximum level and the minimum level Statistics The optional extension 4 adds statistical distribution to the Nor118 functionality There are eight percentiles shown out of which one is freely selectable The class width is 0 2 dB over the entire 120 dB range The statistical distribution calculations employs the F time constant and applies to the 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 Reverberation time A typical Nor118 application is to serve as the acoustician s little blue tool This will require the ability to calculate the reverberation time in octaves and third octaves Units without filters will calculate 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 is based on the integrated impulse response method hence impulses are required as excitation signals Sound power Sound power levels may be calculated from sound pressure level measurements using almost any
72. entile levels offered by option 4 are 1 0 5 0 10 0 50 90 95 and 99 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 5 6 Chapter 1 Introducing the Nor118 Time profile measurements Remember the time when paper based level recorders used to be the only way to capture the time profile of a sound measurement Remember the struggle we all had with calibration and proper scaling of the plotting on the paper With Nor118 instruments equipped with the optional extension 6 you will be able to retain all the advantages of the level recorder principle while at the same time discarding all the trouble No paper no trouble The optional extension 6 level vs time records the time profile of the a weighted equiv alent 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 100ms in enhanced mode When a level vs time measurement is running the equivalent level will be calculated per period thus giving 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 Everything is retained with
73. ents Units configured for the German speaking markets If also equipped with Leq and Tmax the sequence is as follows press FUNC key repeatedly a Leq gt Lmax gt Lmin A Leql 4 Lpeak Le SPL Accessible during measurement only not after 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 pro duce the function and then press the Tc key once or twice EXIT again In both cases the instrument will go back to READY mode The spx 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 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 values are only shown during a measurement never once the measurement is over 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 a
74. epiped measurement surface if a the range of sound pressure level values measured 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 directivity 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 exists additional microphone positions shall be used For the microphone array on the parallel epiped the number of microphones are increased as shown on the next page by increasing the number of equally sized rectangular partial areas If conditions b or c exist additional measurement positions on the measurement surface in the region of high noise radiation shall be used Details on this are given in the 180 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 1 dB from those determined from measurements over the complete set of microphone positions in accordance 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
75. er 4 has been activated while you press the stop key or the pause key Will it assign both 4 and P or s No it won t P and s have priority and they L3 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 N 46 Chapter 9 Multispectrum measurements Multispectrum measurements T OPTIONAL EXTENSION takes the instrument fur ther along the axis of sophistication by introducing multispectrum measurements This upgrade of time profile permits complete spectra 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 yyy 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 multispectrum measurements basic time profile 1 Set up the instrument to make time profile measure ments as described in Basic time profile measurements 2 Press SETUP gt 4 and activate the filters as described in the chapter Frequency analysis Navigate set the parameter
76. es e 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 pres ence of the optional extension 4 and set one of them as you like e Store them for future use 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 spx 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 Asan 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 display mode or from frequency spectrum mode The tables are available during as well as after a meas urement Remember that spi values are shown during the measurement only The tables available are shown in the side bar Display ing the result tables 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
77. es after the last opera tion 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 foil type with acoustic feedback when the keys are depressed Keys used during a measurement or for initiating a measurement remain silent 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 1EC 61672 1 to free field response By selecting the random response correction network included the instrument will satisfy the class 1 require ments in IEC 61672 1 to random response as well as ANSI SI 4 1997 TYPE 1 he nominal correction to obtain flat random response is shown in the figure below 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 Random response correction e N A A uu S W 1 10 Frequency Hz Correction 05 12 55 011025 Random 18 35 16 Windscr ON Preamp ON F SPL 40 s nolse ON c 57 0 l Corr par A 37 2 RWGS RWGS by means of the nc and pec keys Do the same to deactivate Random response correction activated is indicated by an R in the lower line of the display Windscreen The instrument may be used with
78. esolution basic profile 6 enhanced profile 7 Time weightings technical specifications 84 Total range for A weighted levels 85 Total range for measurement of C weighted levels 85 Total range for measurement of Z weighted levels 85 Transfer of data to a PC 81 Trigger conditions 55 U Unlocking the keyboard 79 V Virtual reverberation time 54 W Warm up time 91 Weighting functions A and C or Z weighting frequency mode 27 setting C or Z weighting in global mode 19 Windscreen correction 87 W in the display 56 Z Z weighted levels total range for measurements 85 Z weighting 3 N NN Norsonic Declaration of Conformity We NORSONIC AS GUNNERSBRATAN 2 N 3408 TRANBY NORWAY declare under our sole responsibility that the product Sound Level Meter Real Time Analyser Nor118 to which this declaration relates is in conformity with the following standards or other normative documents EMC EN 50081 1 EN 50082 1 following the provisions of the EMC DIRECTIVE Standards IEC 60651 CLASS I ANSI SII 1986 TYPE ID IEC 60804 CLASS I ANSI S 1 4 1983 TYPE I EN 61260 CLASS I ANSI S 1 43 1997 TYPE I 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 This
79. esolution to 1s and press the pec 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 pec 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 1Nc the resolution will be set to 100 ms immediately Press INC or DEC to adjust or use the NUMERICAL KEYPAD to set the value directly Step size is 25 ms If you key in a value between the valid settings the value will be put to the nearest valid setting The effect of pressing stop before resuming If you terminate an ongoing measurement 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 Norsonic Nor118 User Guide Presenting the L t as a table Numerical presentation of the acquire
80. etting to see the top of the bar graph Use the Nc and DEC keys for this before you enter the calibration menu Carrying out the calibration You will need a sound calibrator of sufficient accuracy i e a class 1 or class O sound calibrator as defined by the IEC 60 942 standard such as the Norsonic sound calibrator Nor1251 or Nor1253 Do as follows Enter calibration mode Press the cat key to gain access to the Calibration menu The display will typi cally look as shown to the right Know the output level of your sound calibrator Some sound calibrators have an output level of 94dB while others like the Nor1251 which is used in the example to the right have an output level of 114dB or even 124dB like the Nor1253 Unless you know the output level of your 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 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 cartridge 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 8dB when using a 114dB 1000 Hz sound calibrator Other frequencies will require different
81. etween 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 multispectrum 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 These are shown in the Fig to the right as well as over Norsonic Nor118 49 User Guide 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 produce 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 M020419 00045 Use a CY keys to 0 2 7 500 move up and down in ta Pe regi ble CO keys to move 5 OkHe 27 to another moment in time 5 3kHZ 19 and Func to scroll through 8 Ok Hz 13 the functions measured 10 0k Hz isp be See Ea 16 k Hz lra 20 0k Hz Sla Po Gs OO pan e C netw z Table 2 dB A 020419 000453 O 2 72500 A network Use Ca CY keys to Leq AR A move up a
82. fers optional extension will be updated similarly Displaying the functions measured The instrument measures the a weighted and c or z weighted SPL Lmax LMIN Leg Le and the Lpgax Note that the SPL Lmax and Lyr 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 Lppax The peak level is not measured per frequency band In addition Tmaxs is not available for frequency analysis applies to units equipped with the optional extension o 29 30 Chapter 5 Frequency analysis However since the frequency analysis is made in paral lel 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 No sp after the measurement During measurements the spy value is updated every second Once the measurement is over the sPpL becomes meaningless A single spL value cannot be used to char acterise the measurement unless it represents some kind of maximum minimum or time integrated average It is thus not accessible post measurement What can be done to the measured S data Data acquired are available for inspection during or after a measurement You may e Switch between sound level meter display and frequency spectrum display e Display the functions measured e Display the result tabl
83. gger condition fulfilled Sound analyseres designed to be used for a broad variety of applications need a set of trigger conditions to be versatile enough Such con ditions may include trigger by clock start measuring at a predefined time of day trigger when the level exceeds a certain predefined threshold trigger on an external trigger signal occurring e g a car passing a light barrier etc A sound level meter albeit as sophisticated as the Nor118 normally provides only one trigger condi tion the trigger on pressing START often referred to as unconditional triggering However reverberation time using external exci tation sources will require a trigger on level exceeds a predefined threshold function so that the instru ment knows when to start capturing the impulse and its decay You will then have to define the level threshold above which the impulse is considered to be present and the frequency band in which to look for the impulse 55 56 Chapter 10 Reverberation time measurements You will note a horizontal line located 30dB below the displayed top scale Remember that the displayed top scale is purely a display feature and not related to the measure ment range setting This line represents the trigger level threshold for the impulse decay capture 4 Use the and keys the 1nc and pec keys to change the trigger level threshold in 10dB steps if applica ble Reverberation time setups cannot be stored and
84. guidelines applicable to every Nor118 menu Alo navigate between editable parameter fields in the menu use the cursor keys The editable field currently selected is shown inverted white text on black background e Use the arrow keys to right of the display the INC and DEc keys to increment or decrement the current setting of the parameter Alternatively use the keypad to key in the required value whenever applicable The sign will appear in the lower line of the display whenever the instru ment accepts numerical inputs Ifyou use the numerical keypad be sure to press ENTER before moving to the next field to alter This is not needed when you use the Nc and DEC keys To leave the menu putting changes into effect press ENTER e There is no CANCEL function available 18 Chapter 4 Simple sound measurements Measurement duration setup menu Meas dur Meas dur Duration Duration 00 05 0 00 05 0 Resolution 00 00 05 N 66 Mx 1103786 Measurement duration setup menu when time profile option is installed left and when i s not right Missing percentiles There may be percentiles 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 con fused with the sampling of the analogue to digital conversion takes place 10 times a secon
85. heir respective companies Every effort has been made to supply complete and accurate information However Norsonic AS assumes no responsibility for the use of nor for the consequential dam ages of the use of this information and or the instrumenta tion described herein Furthermore Norsonic AS assumes no responsibility for any infringement of 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 info norsonic no Copyright Norsonic AS 2001 2002 All rights reserved Norsonic Nor118 User Guide Finding the information you need hank you for choosing Norsonic The Norl18 has been designed to give you many years of safe reliable operation Your approach to the Nor118 documentation depends on what you want to do and how much you already know The Nor118 User Guide has been divided into eighteen chapters or sections plus index Each chapter provides dif ferent information Depending on your requirements and your familiarity with sound measurements as such you may find that you use some parts of this manual often and others not at al
86. hemispherical surface of radius 7 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 measurement 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 hemispheri cal measurement surface is preferred For measurements on a series of similar sources e g machines of the same type or a given family of equip ment the use of the same shape of measurement 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 z shall be described in the test report The Fig shows the characteristic dimension d for the different locations of the source under test Reference box on two reflecting planes Reference box on three reflecting planes Norsonic Nor118 59 User Guide Rectangular parallelepiped For the rectangular parallelepiped reference box there exist three possible configurations as shown in the Fig to the left The characteristic dimension d can be calculated from the following formulae Refe
87. hen octave and fractional octave analysis is switched off e More than 2500 global measurements with all avail able global functions and distribution when octave and fractional octave analysis is active e More than 2500000 samples of L t when only one function is logged corresponding to more than 60 hours with a resolution of 0 1 sec e More than 90000 samples of L t when all 28 functions are logged in profile corresponding to 25 hours with a resolution of 1 sec Environmental conditions Reference conditions The reference conditions for the instrument are as specified by 1Ec 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 Norsonic Nor118 User Guide Warm up time The warm up time for the main instrument without preamplifier 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 microphone with the polarisation voltage Normal sensitivity is reached within one minute Before a recalibration is attempted at least three minutes for warm up is
88. here is only one reflecting plane the microphone posi tions lie on the hypothetical hemispherical surface of area S 2mr enveloping the source and terminating on the Microphone positions on a hemisphere key microphone positions reflecting plane If the source under test is in front of a wall S nr and if it is in a corner S 0 517 The Fig below left shows the location of four key microphone positions each associated with equal areas on the surface of the hemisphere of radius r If a source is installed adjacent to more than one reflecting 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 measured 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 directivity 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 exists additional microphone positions shall be used For the microphone array on the hemisphere an additional 4 point array is defined by rotating the origi
89. ic Nor118 37 User Guide Displaying the result tables To switch between A and C or Z weighted values use Leq 560 mMm the Netw key a aa ee F Min 53 2 Sound level meter LE 63 0 Peak 66 5 display mode Pie E 8 5 00 0530 v 0 05 A g2 0 05 CF 010728 e Leq 37 9 L 0 3 22 39 24 X F Max 39 5 L 1 0 7 F Min 37 3 L 5 0 57 5 I SPL 90 LE 44 9 S L10 0 57 1 SE E Peak 53 5 L50 0 56 0 j A 80 8 I Leq 46 4 L90 0 54 8 Z 83 0 FTmx5 39 5 L95 0 54 5 Ba L99 0 53 9 HE P dE Statistics is optional Units not configured for the German speaking markets will have tables without l Leq Leql and Tmx5 a SPL values To move the graph cursor Use COC keys Use Func to display use the C4 gt keys to move to another another function but not during a meas frequency spectral urement only after weighting network Profile display mode To scroll through the table use the Ca CY A keys but only after a Lea measurement A network WWNNNMMNhY e DONAA ooocoocoeooeo 38 Chapter 6 Basic time profile measurements No back erase in profile pause mode i The resumption of a paused measurement will cause the ten seconds acquired immediately before the pause to be erased This applies to the global measurement but no to the profile Assume you have set up the measurement to also include profile and that the measure
90. ically 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 full hour of the time of day To be active SYNCHRO requires a minimum measurement time duration of 30 seconds per individual measurement 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 be truncated and last a able to measure very high sound pressure levels Going to measure very high levels As an optional extension the Nor118 is without changing the microphone cartridge see High levels in the Technical specifications for details Norsonic Nor118 User Guide little less than 7 minutes and 20 seconds it will last for 7 minutes and 16 seconds to be exact to give room for storage before 09 00 00 The succeeding period will then each be very close to an hour long to enable restart again at 10 00 00 II 00 00 ete Now what happens if you select a period duration whose multiples fail to match one hour If you set up the period duration to say 7 minutes and start the measure ment the instrument will measure in periods of 6 minutes and 54 seconds to enable a restart exactly 7 minutes after the previous period started However the first t
91. ich 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 Sound power calculation based on sound pressure level measurements is also new in this version Although a fairly thorough description is given we recommend that you get yourself a copy of the applicable standard Note that the instruction manual describes a fully equipped instrument Your version may not have all the optional extensions available Extensions may however with a few exceptions be installed as retrofit any time Our objective with this manual has been to address your goals and needs Please let us know how well we succeeded N V vi Contents Contents Chapter 1 Chapter 2 Chapter 3 Introducing the Nor118 Introducine the sound level meter Norl 18 s csscssbinveisucdosetaatussienssmssteanonanestens 2 A Te aa E e sak ae E E A E 2 Tie tuncions wap enea E E E ere ers 3 LThemanicatures am Over Ne 9 osnan a aaa gt Realtone HEQUEHICY ANALY G16 cose sesso cesers aex arcasnansticueteretonciusiabtasescvasseseineeinanicis 4 Time proiio meistre eii Sessea renee Reese renee ia tet Peer eey y err ce rr 5 Wii ltispectrall meri SMe esa E E E RS I S CO T T A E teste AE E 7 EXCellent orno e MONLO senine E 8 The principle Or optional CEON Seisson sne ia 8 Check which extensions are mastilo ecenccinneses annin ne en 9 Taking a closer look Toking acloser look
92. ill 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 130 90 00 05 30 010728 os 22 39 24 7 fot z ISPL 902 IAA 4 lt lt lt 16 25 Tks Ek Az A 80 8 010804 10 gag 18 03 42 E es AF SPL 77 0 P i dB Sound level meter Spectrum display display Making a frequency analysis To start a frequency analysis measurement 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 conr key To resume a paused measurement e Press the pausE contT key again Upon resuming the instrument will go on measuring until the total measure ment time elapsed equals the preset duration Observe that data acquired the ten seconds immediately preced ing 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 meas urement is resumed the back erase feature see below will not be activated To switch betwe
93. ill not work in other instruments Do not change these codes as you will then loose the optional extensions installed and activated Norsonic Nor118 9 User Guide The options available The below list was complete and exhaustive by the time of printing of this User 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 Opt 0 Lomaxs Leqr and L measurements accord ing to German Standards eR Opt Ope gt Ojon Opt Opt Opr gt OE Opt 2 Opt Y octave real time filters 8 16 000 Hz octave filter bands Statistical calculations Parallel F s 1 time constants Basic time profile mode Enhanced time profile mode Multispectrum measurements O ON HW U A Q FR Reverberation time calculation 10 Sound power mode for Lwa measure ments according to 1803746 e Opt 20 Extended measurement range enabling high end range up to 150 dB peak or low end self noise correction depending on microphone in use e Opt 21 Display output connector for use together with Video Interface Nor266 This option must be ordered at the same time as the new instrument 10 Chapter 2 Taking a closer look Taking a closer look at the instrument Yr MAY HAVE TO ASSEMBLE the instrument the first time you use it Be sure to take ut
94. ill show the folder and file number as can be seen from the Fig below Allaspects of the memory handling are discussed in detail in Memory handling Printing out the results By connecting a printer to the Rs232 interface the results can be output to a printer This is treated in detail in Making hardcopies N When data are stored Folder and file number of data stored The S indicates Stored 011016 0001S g0 0000S 0 04 E Leq 40 c 53 9 A 45 7 E a Basic time profile measurements NSTRUMENTS 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 measurement into smaller periods of time all having 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 extension 7 allows a period length from 100 ms and upwards in 25 ms steps but in 1 second steps above 1 second period length 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 measurements represent the profile In the display the global measurements are denoted pronounced sigma while the profile measu
95. ime the full hour is reached one period will be truncated if needed to lock the measure ment onto the full hour at least once The odd choice of period length will however fail to make the full hour synchronisation work in a sensible way The principle has been designed with period lengths of an hour half an hour 15 minutes etc in mind 4 Keyboard lockout locking the keyboard to prevent unauthorized operation You may lock the keyboard to prevent the instrument from being tampered with while it is left on its own To lock the keyboard Press lt gt gt lt to lock the keyboard To unlock a locked keyboard Press lt gt gt 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 79 80 Chapter 16 Noise monitoring Setting the storage mode To set the storage mode Press sETupP gt 1 Instr gt 1 Storing Use the cursor keys located below the display to navigate in the menu as usual and set the storage mode as required 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 What information will you need and how detailed should it be Using windscreen The effect of using Z a windshield is discussed in Windscreen in the chapter Technical specifications L e Mea
96. in the instru ment hence there is no paper involved in the process When you are going to make a measurement the maximum number of periods at your disposal will depend entirely on the amount of free memory available It will by no means depend on the duration of each period This is because a period is a period in the sense that it will occupy a fixed space in the memory irrespective of its duration Given the large memory of the Nor118 the memory can hold approximately 2 500000 values the period dura tion 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 So we added a global analysis to all time profile meas urements It just runs in the background and makes little fuzz about its presence Switching between GLOBAL and PROFILE is easy a dedi cated key on the front panel the X A key lets you toggle between the two The pronounced sigma denotes the global analysis while the A pronounced delta denotes the time profile Consequently when you have set up for a time profile measurement by defining the total duration and the time resolution you have in fact prepared the instrument for two parallel measurements the global and the profile Abso
97. ing 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 END RIGHT key The corresponding percentile value will now be displayed given that the meas urement duration was long enough to provide a sufficent number of samples Using ENTER will not work here 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 extension 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 Nor118 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 The structure of the Nor118 is very simple the folder has the name of today s date and the files are numbered consecutively from 0001 and upwards Consequently the maximum number of measurements per day is 9998 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
98. l The very first chapter acquaints you with the Nor118 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 instrument with a presentation of all major parts and the keys of the keyboard Calibration is a vital point ensuring that your measure ments are sufficiently correct for the purpose Therefore a separate chapter has been devoted to this How to measure with the Nor118 is described in the following chapters The first measurement description outlines the use of the Nor118 as a simple sound level meter he second description extends the description 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 preceding measure ment 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 recommend that you read both the L t chapters to get a good overview New in this version of the instrument is the multispectrum wh
99. l the correction is 3 dB 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 General I O socket A 15 pin socket for general 1 0 is placed on the right hand side of the instrument Socket type ITT CANNON MDSM 15PE 250 8550 021 The general o socket 89 90 Chapter 18 Technical specifications Pin Signal Dir Remarks 1 DO 1 Out Digital output DO 2 Out Digital output 3 DO 3 Out Digital output for calibration only high calibration ON 4 DTR Out RS232 5 TD Out RS232 6 PWR Out 3 3V max 10mA T GND ref digital lines 8 DI 1 In Digital input 9 DI 2 In Digital input 10 HEAT1 In Power mic heating 11 HEATO In Ref for HEAT 1 12 DSR In RS232 13 RD In RS232 14 GND ref analogue signal 15 AC out Out Analogue output Housing GND Instrument casing Analogue output The analogue output is normally a reproduction of the input signal from the microphone obtained by a digital to analogue converter 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 10 mA Gain accuracy at 1 kHz 0 4 dB Frequency response re 1 kHz
100. lative 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 0 1 0 2dB see Preamplifier attenuation in the Technical specifi cations for more on this Simple sound measurements ESPITE ALL ITS ADVANCED CAPABILITIES the Nor118 may still be used as a simple sound level meter The only thing you really need to set up is the measurement duration which at least must be set up to match the amount of time you intend to be measuring If it is set to a longer time this will constitute no problem just press the stop key when you want to terminate an ongoing measurement However you should consider the settings of the time constant and the spectral weighting c or z weighting see Setting c or z as spectral weighting network for more on this also but once they are set the instrument will remember these until they are changed to something else Setting the duration Your instrument may or may not be equipped with the optional extension 6 which is the time profile logging 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 overleaf Norsonic Nor118 User Guide Q Navigating in the menus Observe the E following general
101. lute vs relative time If exact time information is important just put the instrument in absolute time mode by pressing the key ass t All periods will then have the date and time of day they were acquired displayed If time elapsed since start is sufficient push the key again to return to relative time This is a display function the absolute time is always recorded for all measurements Setting up is easy to do After youve 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 measured 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 The time profile logs the a weighted equivalent level the a weighted maximum sound pressure level and the Zz or C weighted peak level The enhanced profile option In need of even better resolution or better control of the functions measured No problem The time profile extension can be expanded into the enhanced profile extension our option 7 for the Nor118 Order it when you purchase your Nor11
102. 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 meas urement For 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 Adding marker number 4 how ever will assign this marker to the current period plus all 7 8 Chapter 1 Introducing the Nor118 consecutive periods until the marker again is deactivated A typical application for marker 4 is to denote intervals of particular interest The keys to use The keys used to enter the markers are CAL marker 1 PRINT marker 2 Ex1T marker 3 and ENTER marker 4 since these keys are the lower most keys of the front panel and thus easy to reach during a measure ment None of these keys are used for other things during a measurement either Excellent for noise monitoring With the Nor118 you are able to do nearly all types of noise measurements community noise industrial hygiene
103. measure levels up to 150 dB peak The measurement range is then 20 140dB RMS Without the need for range setting As for all our sound measuring instruments many of the features in the Nor118 are optional and can be added upon order or as retrofit whenever required In this way you don t pay for features never used In this chapter we would like to introduce you to the Nor118 and explain to you some of its unique features The Nor118 is a very powerful sound level meter some would say it is more of a palm size sound analyser definitely made to measure No external modules Different requirements and standards call for different functions to be measured The Nor118 comes with an extensive set of functions available in its basic version A multitude of other functions are available as optional extensions The modular design of the Nor118 enables functional expansion to take place when you need it and not neces sarily at the time you purchase the instrument Unlike certain other solutions commercially available the Nor118 optional extensions remain in the instrument once installed and activated There is no need for pc cards to load and unload the extra modules every time you need other features The functions available Even in the basic version the functions available with the Nor118 include the following e SPL The Instantaneous Sound Pressure Level e Lmax The Maximum Sound Pressure Level Lyin The Minimum Sound Pressu
104. ment 20 frequency analysis 25 frequency cursor moving back and forth 29 inserting a pause 20 frequency analysis 28 making a global frequncy analysis 28 making the spectrum appear A weighted 28 measuring very high levels 18 missing percentiles 18 no SPL values after the measurement 22 on units with profile installed 19 percentiles table sequence 23 range of user defined percentile 23 result tables in detail 22 resume an ended measurement 21 resuming a paused 20 Appendix 1 Index returning to live display after a measurement 21 selecting C or Z weighting 19 setting the display topscale 20 frequency analysis 29 setting the duration 18 setting the duration for frequency analysis 25 setting the user defined percentile 23 setting up for 17 starting a measurement 20 tables frequency analysis 32 terminating an ongoing 20 user defined percentile setting 24 Global vs profile a discussion 35 GND 81 GSM modems cable needed 81 H Hardcopies defining functions to print 77 examples of printouts 77 generating 76 printers supported 76 setting up for 76 starting a printout 77 HEATO 81 HEAT1 81 Hemispherical measurement surface 58 calculating the characteristic dimension sound power 59 radius requirements 59 Highpass filter filter type 83 of input section 83 High levels by reducing polarisation voltage 87 HP DeskJet 76 HP ThinkJet 76 IEC61672 1 82 IEC 61672 19 Indication range 84 Inherent noise compe
105. ment 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 r k The line denotes miii Pe aege oO periods are 14o A A Leq 42 8 marked When you later press PAUSE 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 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 ambigous 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 equipped with the multispectrum extension you may even log the spectrum as a function of time See the chapter Multispectral measurements for more on this This chapter deals with profile measurements only For details on global frequency analysis see the chapter Frequency analysis Making measurements All you need to do to set up the Nor118
106. meter 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 Setting the amount of attenuation e In 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 20 be corrected automatically for the self noise of the microphone The noise levels for each of the spectral weightings must be specified The correc tion is applied by unlinear level subtraction The option Correction 05 12 55 011025 Random 18 35 16 Windscr ON Preamp ON F SPL 40 S noise ON c 57 0 l Corr par A 37 2 RWGS RWGS Correction Noise correction Corr par 1 Pre amp Random 2 Nos comp windsecer ON Preamp ON S noise ON Ln 19 9 LnC 19 9 LyZ 19 9 RWGS l Corr par RWGS Norsonic Nor118 User Guide allows levels close to the self noise to be displayed with reduced level linearity error When the level is equal to the self noise leve
107. most care when mounting the microphone cartridge onto the preampli fier Always keep the preamplifier disconnected whenever you are screwing the cartridge onto the preamplifier and screw only finger tight The instrument is powered from four AA size batteries which are inserted as shown below If you use rechargeable batteries these will not be recharged if you connect the Nor118 to an external power supply The front panel keys all produce an audible click when depressed to confirm successful operation However the click is disabled during a measurement to avoid interfer ence with low noise level measurement sessions Example of batteries inserted correctly On the use of batteries The Nor118 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 15V to the instrument will not charge rechargeable batteries but power the instrument in lieu of the internal batteries The internal calendar clock is powered by an inte grated battery with approximately ten years of battery life time q No recharging Connecting an external E Dc source 11 15V to the instrument will n
108. n for High Level Mode 1 10 Frequency Hz By lowering the polarisation voltage the level range can be extended without chang ing the microphone cartridge This feature shall be used in combination with the Nor1225 cartridge only Level Range HIGH 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 attenua tion in the preamplifier Typical values of the attenuation is 0 2dB The correction can be set in the range 0 0 to 9 9 dB The correction can be switched on oF F to facilitate applications of other transducers without preamplifier 05 12 55 011025 Random 18 35 16 Windscr ON Preamp ON Snoise ON F SPL 40 c 57 0 l Corr par A Si 2 RWGS RWGS Correction PreAmpAttn Corr par 1 Pre amp Random 2 Nos comp Windscr ON Preamp ON Snoise ON Te SCOrr pat RWGS RWGS Activating the preamplifer attenuation e To activate the preamplifier attenuation press SETUP gt 1 Instr gt 6 Correct to gain access to the Correc tions menu Navigate in the menu as usual and activate the correction para
109. nal 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 require more measurements in the region of high radiation Norsonic Nor118 61 User Guide Microphone Array on the Hemisphere One reflecting plane Measurement surface i Reference box 0 89r 20 Two reflecting planes wane LG LLLLMLLLLLLALMLLLLLU LLL LILLIA ULM Measurement surface 1 Q93 sa NB Dimen a sions in metres Reference box NB Dimen sions in metres Q Key microphone positions Additional microphone positions Key microphone positions are numbered 4 5 6 and 10 additional microphone positions are numbered 14 15 16 and 20 Three reflecting planes SS 62 Chapter 11 About sound power measurements Parallelepiped measurement surface The measurement distance d is the perpendicular dis tance between the reference box and the measurement 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 1 m may be selected for large sources There are environmental requirements that should be satis fied for the value of d selected In brief the environmental requirements state that the reflecting plane must
110. ncy analysis The all digital technology used in the Nor118 made it natural to include filters an important input from many of our customers We made them parallel right away because you have already told us how important real time frequency analysis is to many of you Octave band or third octave band measurements the choice is yours depending on how you prefer to configure your Nor118 The octave band measurements span the range 8 Hz to 16 kHz while an upgrade to option 3 will provide you with third octave band measurements in the range 6 3 Hz to 20 kHz The two bandwidths share the type of functions measured In a single frequency analysis the Nor118 measures e SPL The Instantaneous Sound Pressure Level Lmax The Maximum Sound Pressure Level eLmn The Minimum Sound Pressure Level Ts The Integrated Equivalent SPL Lr 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 meaningless and therefore not listed in the result tables If your Nor118 is equipped with parallel time constants option 5 the list of functions measured simultaneously can be expanded to include functions with F s and 1 time constants at the same time The frequency bands measured are all visible in the display with no need for horizontal scrolling The ft key lets you enter and exit the spectrum display Furthermore the instrument
111. nd 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 weight ing functions The result table Once youve pressed the TBL key the display will typically look like this p 0 08 A 0 05 A Measure EE eq 409 Leq 37 9 ES Spectral ment time Max 47 6 FMax 395 weighting F Min 36 9 F Min 37 3 applied LE 49 4 LE 449 Peak 62 0 Peak 53 5 I Leq 44 5 F Tmx5 47 6 F Tmx5 39 5 F SPL 379 FSPL dE i gt dE Measurement is running ILeq 46 4 Observe that once the measurement no longer is running no sPL value is available Units not configured for the German speaking markets will have tables not containing the 1 Leq Leqt and Ts Values Displaying the result table using the other spectral weighting function Spectral weighting network indicator O 05A Leq 37 9 Leq 56 0 F Max 39 5 F Min 37 3 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
112. nd down in frequency incl spectral F Max 49 3 weighting networks and F Min 48 6 COC keys to move S Min 54 1 to another moment in time and Func to scroll through the functions measured 50 Chapter 9 Multispectrum measurements Global mode Profile mode TBL 130 A 00 05 30 k A net work 010728 22 39 24 I SPL 90 a 80 83 Z 83 0 RSs oe ee eee oe ee fey Os CO DIDI NIN NO PO ime 60 CO SIO OT e Pe LO Ww rer 50 dE e Multispectrum mode 16 125 1k 8k AC TT Optional requires statistics E a Leq 24 8 5 0kHz Mk Global frequency mode E W020419 0004S 0 08 0 33 TFR 0 2 7 500 oct 2 0kHz oct a E oct Lea 250Hz ma 5 OkHz Leq 40 0 500HZ i 6 3kHz F Max 47 2 1 OkHz 8 OkHz or eee H F Min a 2 0k Hz i 10 0k Hz 34 7 12 5k Hz LE E j 16 0k Hz 20 0k Hz AF SPL 65 5 A netw dE TBL E EEEa o E 4020419 0004S 0 2 7 500 A network F SPL 48 4 Leq 48 4 F Max 49 3 F Min 48 6 S Min 54 1 l Ti p ga E ies pa ro i i a T ie www oe Soocoooo owt bn an G2 G2 G2 GR GR dE Both tables are accessible during measurement you can even start a measurement from within any of the tables All functions available for a profile measurement a
113. ndwidth Norsonic Nor118 User Guide Setting the duration Your instrument may or may not be equipped with the optional extension 6 which is the time profile logging 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 Measurement duration setup menu Meas dur Meas dur Duration Duration 00 05 0 00 05 0 Resolution 00 00 05 N 66 Mx 1103786 Measurement duration setup menu when time profile option is installed left and when it s not right 25 26 Chapter 5 Frequency analysis 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 pro file extension the basic version as well as the enhanced version may log the a and c or z weighted 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 Statistics Even if your instrument is equipped with the optional extension 4 statistics the percen
114. nic Nor118 11 User Guide minutes However this does not apply if the instrument is measuring including being paused during a measurement not when powered from an external source Setting the polarisation voltage To set the polarisation voltage e Press SETUP gt INSTR gt 4 POL VOLT and use the VERTI CAL CURSOR KEYS to select 200 V polarisation voltage ON or OFF Polarisation voltage Pol volt The polarisation voltage setting menu opens up for the use of prepolarised microphone cartridges OFF q A prepolarised microphone cartridge will normally exhibit reduced sensitivity when exposed to polarisation voltage It will regain its ini tial sensitivity 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 guar antee for all brands cannot be granted Norsonic is not liable for consequential damages of the use of polarisation voltage 12 Chapter 2 Taking a closer look q Navigating in the menus Observe the E following general guidelines applicable to every Nor118 menu To navigate between editable parameter fields in the menu use the CURSOR keys e The editable field currently selected is shown inverted white text on black background e Use the arrow keys to right of
115. 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 coefficient 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 machines larger 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 measurement distance from the box The microphone positions on the parallelepiped meas urement surface are shown on the following pages The area S of the measurement surface according to the micro phone position figures is given by the formula S 4 ab bc ca where a 0 51 d 6 0 51 dand c 0 51 d and Z and are the length width and the height of the reference box Ifa source is installed adjacent to more than one reflect ing plane reference shall be made to the corresponding figures Additional microphone positions Sound pressure level measurements are required at additional microphone positions on the parallel
116. nsation 89 Instrument codes 9 ISO 3476 58 ITT Cannon MDSM 15PE 250 8550 021 89 K Keyboard lockout 79 Key microphone positions hemispherical surface sound power 61 L Least square fit 53 LEMO socket microphone input socket pinout 83 Level detector type technical specifications 83 Level distribution technical specifications 84 Live display returning to after a measurement 21 Locking the keyboard 79 M Manual storage mode 78 Markers adding 44 hierarchy of priority 45 keys used to insert markers 7 pause in time profile 38 principles and applications 7 stop marker in time profile 38 termination in time profile 38 Maximum reverberation time possible 54 Max output voltage AC out 90 analogue output 90 Measurement making a simple sound measurement 20 Measurement duration setting 17 setup menu 18 basic time profile 36 technical specifications 85 Measurement modes a navigational map 50 Measurement mode indicator of stored files 75 Measurement range for C weighted peak levels 86 Measurement Surface defining for the Nor118 sound power 71 Memory handling 72 deleting folders or the entire memory 75 deleting a single file 74 deleting files and folders 74 file naming conventions 72 folder structure 72 memory size 72 memory structure 72 recalling stored setups and data 73 storing a measurement 73 storing a measurement setup 73 Menus navigating in 12 Microphone heating 90 Microphone input socket pinout 83
117. ocated 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 and keys The position of the graph cursor the frequency cursor determines the frequency band to be used as trigger band The Display top instrument is in scale Reverberation time mode 16 125 1k ak AZ 021104 10 14 49 21 F SPL 30 8 1 0k Hz G Making reverberation measurements Setup of the Nor118 for reverberation time measurements is really simple There is no range or duration setting all you need to do is to set the trigger level To set up for reverberation time measurements 1 Press MODE gt 2 Rev to enter reverberation time mode The display will now look as shown above 2 If needed set the filter bandwidth to or octave requires that filters are installed see the chapter Frequency analysis for details Norsonic Nor118 User Guide The R in the upper left corner of the display indicates 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 3 If 1kHz is not suitable as trigger band which may well be the case when using a paper bag as excitation source use the CURSOR keys to move the cursor in the usual manner q Whatis trigger To start a measurement 5 the instrument will need to have a tri
118. on 53 excitation source 52 how it is measured 53 important terminology 53 instrument requirements 52 least square fit 53 leaving the table 57 making another measurement 57 making measurements 56 maximum reverberation time possible 54 minimum reverberation times possible 54 OL appearing in table 57 result tables 56 returning to READY mode without measuring 57 Schroeder method 53 setting up for measurements 55 spatial averaging and backwards integration method 53 terminating an ongoing measurement 56 theory 52 trigger conditions 55 R in the display 56 S Sampling for statistics 18 Schroeder method 53 Self noise compensation 89 Self noise levels of instrument 84 Sensitivity of free field microphones 15 of microphone cartridge See Calibration Sensitivity for magnetic fields 91 Sensitivity for vibration 91 Serial I O port baud rate 90 Sigma delta converter technical specifications 83 Size and weight 91 Sound calibrator 15 Sound power acoustical conditions requirements 58 applicable standard 58 background noise 68 calculating the characteristic dimension of hemispherical measurement surface 59 characteristic dimension 58 characteristic distance preferred value parallelepiped 62 d0 58 displays available 69 environmental correction factor 66 example of printout 77 hemisperical surface 58 hemispherical measurement surface radius requirements 59 key microphone positions hemispherical surface 61 max num
119. ored 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 Retrieving stored setups and data Measurements stored are easily retrieved To retrieve a stored setup or stored data 1 Press the RECALL key 74 Chapter 14 Memory handling 2 Follow the procedure explained in the side bar 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 retrieved something from the memory is reflected in the text line appearing at the top of the display see Fig Clearing files and folders in the memory To delete files and folders in the directory e Press the cLEAR key The display will now produce the CLEAR menu In order to successfully locate the files and folders you want to delete you must apply the procedures discussed in Retrieving stored setups and data including the side bar on this page Clearing a single file To clear a single file 1 Make sure that the file to be cleared is selected i e highlit shown as white text on a black background Pres
120. ot charge rechargeable batteries but power the instrument in ieu of the internal batteries Battery Voltage vs Time The Nor118 offers a graphic presentation of the battery versus time history To display the battery voltage vs time e Press the BaTT key Press again to exit the menu 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 Battery Combined C yy 4 54 Time elapsed battery voltage T 04 46 14 since battery as an f t a replacement The display will now indicate the combined voltage of the four batteries and the use time elapsed since the batteries were replaced The graph is updated every sevenminutes and each pixel corresponds to seven minutes in the hori zontal direction and 0 25V in the vertical direction 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 directory called BarLow Memory contents is retained without the use of electrical power flash memory If the instrument is connected to an external pc source the external source voltage vs time will be shown without voltage and use time information empty graph If powered from internal batteries and left unattended and unoperated the Nor118 will switch itself off after ten Norso
121. ox Width 1 00 m Reference box Height 1 00 m Measurement distance 1 00 m Measurement surface area 21 00 m2 A weighted sound power Lw 73 7 dB A Surface sound pressure 60 5dB A Background noise correction K1 0 0 dB Environmental correction K2 8 5CdB Qualification method Maximum C weighted Peak 99 1dB Impulsive noise Yes 78 Chapter 16 Noise monitoring Noise monitoring De TO ITS LARGE MEMORY and the high dynamic range the Nor118 is well suited for noise monitoring applications Some installations semi permanent or per manent are based on tight computer control while others leave more of the job to the measuring instrument itself The Nor118 can be used with success in both types of systems The Norsonic environmental solutions contain a com plete range of equipment and accessories for environmental noise measurements and monitoring all the way from outdoor microphone units via enclosures and transmis sion cables to controlling and post processing software A detailed presentation is available on www norsonic com Automated storage of measured data The Nor118 can be set up to measure for a predefined period in time and then store the measured data Once the data have been stored the instrument will start to measure for another period of the same duration 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
122. paren eer err yr yr E ere errr 24 Frequency analysis Feeney ANGI GIG a I E A 23 S a E A E E E A E 23 E He E A a E A O 29 S E A E A A E E 26 Donuments withtime pronle mota lled sesaran 26 Consider serune ibhetiime cons AN eiaei Enes eni 26 petting C or Z as spectral weiehting network oscsssmiassiirnmiie 2d Avano the etc Ue 9 jay oe 613 came tenner eee nen nnn ert Tener ny er eee ee arts ee ene 27 OW itenine todisplayine the SPC CEU asses cs sransesdecsatenarencdsiisanisnsecsdaavabevaionsvic 28 Makino Ae IN yay 1G arcsin er 28 Renno AML CNC IeasUT CME ME sess E whee calssoateedonss a9 Tebi kene ATE aa a A A E E ee 29 H you ve measured tor less than ten SECON Ss oncscncsssissetencsitsnsisonsrassavancsdbencsig Pr Displaying the TUNCHOMS Measured unionien e 29 vii viii Contents Chapter 6 Chapter 7 Chapter 8 Chapter 9 No PLEaner hemen ur mieh ersin 30 I Dig play er SSE CAC cn EE T 30 DEALS ICG 1s plains the percentile eniisssnersin 30 ROM POE SGU Calas ates seca srag E E TETE 34 Bem Wie OU Ce Re aM aesenentsaratesat A E sauces esa seonedsnieaeansanncastee 34 Basic time profile measurements Basic time OTIS medsuremeniS ssoisie irene 35 Global ys Prole sionerien En E OAE E E 35 Makino maea enie e oa Sea E E an sonaters 38 Hee hic 0151 82a 9 feel IF ag ee a7 a ne r rrr ener eee ere reser ree ee 39 Enhanced time profile measurements Fananced iiime pronle MeASUTEMEINEG ccassaasigeactendencurisussenasinah sess shaved
123. pply even here If your instrument supports the use of mark ers they may be used in the usual way Pause and global Norsonic Nor118 51 User Guide back erasure also works as usual For a discussion of these features turn to Basic time profile measurements Enhanced time profile measurements and Adding markers to a measure ment NN 52 Chapter 10 Reverberation time measurements Reverberation time measurements HE OPTIONAL EXTENSION 9 for the Norl18 permits measurements of the reverberation time If your instrument is equipped with filters the reverberation time is measured in every frequency band Units without filters will calculate the reverberation time employing the spectral weighting circuitss only a and c or z weighted results The calculation algorithm used complies with the requirements set by the 180354 ACOUSTICS MEASURE MENT OF SOUND ABSORPTION IN A REVERBERATION ROOM in its latest revision and the 1803382 ACOUSTICS MEAS UREMENTS OF THE REVERBERATION TIME OF ROOMS WITH REFERENCE TO OTHER ACOUSTICAL PARAMETERS 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 immediately 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 On
124. presented as valid 160 Hz 0 38 200 Hz 0 31 250 Hz 0 26 0 13 31 Sinz 0 21 Minimum reverberation times possible SIU a 0 17 Nothing changes infinitely fast in nature It will always oe g E take some time to determine the level in each frequency Sera ole band with sufficient accuracy This is related to the BT 800 Hz 0 10 product BANDWIDTH x MEASUREMENT TIME which 1kHz 0 08 0 04 states that the narrower the bandwidth the longer time 1 25kHz 0 06 it takes to determine the level at a given standard devia 1 6kHz 0 05 an 2kHz 0 04 0 02 Likewise the filters are not cleared instantly if the input f f 2 5kHz 0 04 signal is removed suddenly Instead they have a finite decay which may be considered as a virtual reverberation oe del 0 03 time The narrower the filter is the longer this virtual 4kHz 0 02 0 02 reverberation time will be 5 kHz 0 02 The minimum reverberation times for the Nor118 6 3kHz 0 02 are listed in the table to the right If reverberation times 8kHz 0 02 0 02 shorter than those listed in the table are encountered or Japa ae the minimum distance to the noise floor is violated the l instrument will produce a in the reverberation time table z ee oes to indicate this C 0 12 0 12 On the other hand the maximum reverberation time Z TBD TBD possible to measure is 8 seconds in the Nor118 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 l
125. re Level des The Integrated Equivalent SPL Le The Sound Exposure Level Lprax The Maximum Peak Level The spectral weighting functions a and c or z weighting are available for all functions including the Lpgax The z weighting will replace LIN or FLAT as these have not been properly defined by any standard At the time of printing the z weighting appears in the draft for 1Ec 61672 likely to be approved as an international standard within short time As an optional extension the instrument functionality can be expanded to include the ability to measure with all three time constants F s 1 applied simultaneously Norsonic Nor118 User Guide 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 version is capable of logging any combination of functions available with the Nor118 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 100 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 Nor118 can do real time frequ
126. re indicated Typical battery life time DURACELL ULTRA M3 8 hours External pc 11 15 volt Power consumption approxi mately 1 4 watt dependent on selected modes of operation External pc source should have source impedance less than 1 ohm and be able to supply at least 300 mA The mains adaptor Nor340 is recommended for use with the instrument If the external supply falls below 9 V the instrument will use the internal batteries if available If the instru ment has switched off due to loss of power or insufficient supply voltage the instrument will automatically switch on and resume normal operation after reapplying the external pc supply Socket for external pc 1 3 mm plug negative voltage on centre terminal The instrument will automatically switch off if the battery or external voltage is too low for operation within the stated specifications The maximum battery voltage for conformance testing is 4 x 1 6 V 6 4 V The instrument has a calendar clock with a typical lifetime of more than 10 years Contact your Norsonic service department for change of this component After replacement the instrument need factory calibration and to re install the options Display The display is a monochrome transreflective LcD graphi cal display with 160x240 pixels WxH with automatic temperature compensation for contrast and viewing angle Pressing the LIGHT key illuminates the display The light switches off automatically 2 minut
127. rements are denoted A pronounced delta To switch between the modes just press the 2 lt gt A key Norsonic Nor118 User Guide The tag stored in a buffer Likewise the Lmax and Lm and the is measured for every period separately and Lppax are measured for every period All functions are A weighted apart from the peak level which can be set as c or z weighted The enhanced profile ext 7 provides more options see Enhanced profile measurements Profile measurements may be made in parallel with global frequency analysis filters are optional and in paral lel with the traditional sound level measurement described in the chapter Simple sound measurements If your Nor118 is The time profile is no less than an electronic level recorder iiss fy r 39 6 dB Chapter 6 Basic time profile measurements The measurement duration setup menu Total global duration Meas dur a of measurement puration Selected resolution 00 00 05 No of periods with lution selected duration an 00 00 resolution Max No of periods N 2 depends on the amount ___ Mx 707174 of free memory avail able 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 duration divided by the profile is not an integer Which resolution should you use This will always be a trade off betwe
128. rence box on one reflecting plane Reference box on two reflecting planes I 9 gt y do Fy 15 13 Reference box on three reflecting planes do yl ne 6 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 measurement surface shall be equal to or greater than twice the characteristic source dimension d and not less that 1 metre The radius of the hemisphere should be one of the 60 Chapter 11 About sound power measurements 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 1803746 If so such large values shall not be used The environmental requirements state that the reflect ing 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 coefficient 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 Hemispherical microphone positions If t
129. reset duration The measurement has now ended successfully as opposed to if you press the stop key to forcefully termi nate an ongoing measurement If you now press the pAUSE CONT key the instrument will resume the measurement and go on measuring for another 5 minutes so that the total measurement time assumes Io minutes i 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 way of prolonging a measurement will not activate the back erase feature Norsonic Nor118 User Guide The back erase feature When you press the pAusE CONT key during an ongo ing 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 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 measure ment 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 updated to reflect the back erase Note that the statistics buf
130. roduction 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 serur followed by 4 The instrument will now enter the measurement control display 3 The Nor118 allows 1 40 microphone positions 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 key next page 4 At the bottom of the screen the averaged sound pres sure level based on the measured microphone positions is displayed Each microphone position is selected by moving the field cursor using the or keys to the selected position and then pressing the start key The screen will show the normal measurement display during a measurement and return to the control screen and display the measured Lgo value for the measured positions at the end of each measurement Background noise A background noise measurement is required to have the instrument calculate the background noise correction K for you On pressing the Func key the background noise measurement control display is displayed This test fol Norsonic Nor1
131. rre Teter ere 84 E eA OV Se E T E E A AE E anssonceene 84 Sao 1S tr reise E E ET 84 O E EN A tet sess io E A EE 85 Measurement duration and Teso ON snrrc a 85 Total range for measurement of A weighted levels sssini 85 Total range for measurement of weighted levels cisc ccsssctscsseissiesedasoseaccates 85 Total range for measurement of Z weighted levels ccicccscassosscesssccussonssecaces 85 Measurement tance for C weighted peak level siisscscatsoctuseriscincesssravancsaheatiie 86 TOS 6 SU OD Yes roa cee ar E tes A E E 86 DONS cect E E E E A E desateaioase 86 Ea a spe gta st E E E E ao eeapscensisiaseiestean ancaae 86 Adusien or MIC ACE 1 Cel Oct cates ae se ceasnseactnedegte a ecnceentess 86 TINGS Ws ag de ete rsa E S A A E eaaeceees 87 WET NCCES E E E E E hentia E 87 E E T saves E E yest niasniastennsannatice 88 SL NONE COPEN A O aa E E O arrays 89 Difiraction ALOUNG the INSEL UMIENE CASING sisenemise 89 xii Contents Appendix 1 C OE N A E E E enavensasteanccrecane 89 AAO SOU OE P T A E SET E NET 90 So OD I aE E N A E 90 Doa e a E E E 90 B E i A AEA save oat EA E E E 90 Mieropione noi i eee E Acta tieasaniageaherehcsiete 90 D E o e EA E AEE aid E E send tedaanecnsent 90 E MUA COMIC CIOS E E E E wise catsnoateeaeees 91 a E E E T A E sbactascttignricecnse J1 Sen VItY TOF e a A E E T 91 OEMS Or magnete Meld Serisinin ie Tirones e EE E i Sra E a E A E E 91 Tilonnation TOF toniormance TESEN Pisigan a a J2 Index nor118 REAL TIME A
132. s The capabilities and setup options of your Nor118 will depend on which of the available extensions it has been equipped with Extensions are modules made in hardware or made as software in the instrument or e g as software for your pc available for your Nor118 Norsonic extensions are always optional and hence often referred to as options In this way you do not have to pay for features youre not going to use anyway However you may find that your tasks are expanding into new areas of acoustics as time goes by Therefore a typical Norsonic extension will be available for installa tion as retrofit Check which extensions are installed Unless you are certain about the extensions installed in your Nor118 we recommend that you spend a little time looking into the matter The extension menu Press sErup gt 1 gt 0 although you wont find the 0 listed as an option in the Instrument setup menu The menu contains a unique 1D code which identifies the very individual instrument whose menu youre look ing at In addition the menu contains three codes These codes enable the extensions activated for this instrument The codes take the 1p number into account and are valid for this individual instrument only e To leave the menu press ENTER Note that the instru ment will restart as a consequence of this e To leave the menu without restarting press EXIT MN g Note The codes are unique for each 5 instrument and w
133. s 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 enhanced 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 1nc 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 LCG ERREP par E Use the NETW key to gain access to oe c z weighted functions and the filter band func tions as well oooh hmm Setup menu with multiple time constant option left and without the multiple time constant option right Norsonic Nor118 User Guide If you fail to activate functions for the filter bands there will be no multispectrum data either Making multispectrum measurements Multispectrum me
134. s is optional Your user editable percentile can be set to anything in the range 0 1 99 9 both extremes included Data measured but not yet stored may be subject to changes in the user defined percentile This means that as long as you have not stored the acquired data you may change the percentile as many times as you want but once the data are stored 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 Missing percentiles There may be percentiles 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 con fused with the sampling of the analogue to digital conversion takes place 10 times a second For comparison the sampling of the analogue to dig ital 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 are shorter than these minimum limits will not produce percentile values for all pos sible settings of the percentiles Norsonic Nor118 User Guide Editing the user defined percentile To enable the editing
135. s 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 2 Use the cursor keys to move the cursor to CUR FILE and press ENTER again The file is now deleted Retrieving stored setups and data Folders Recall 0001T 010831 0002T SETUP 011014 011016 011018 Once you ve pressed the RE CALL key the display wil show a list of folders and the con tents of one of them here this is the folder 010830 Use the VERTICAL CURSOR keys to move up and down in the file list of this folder Files of selected folder Recall 010830 010831 011018 Recall 010830 010831 SETUP 011014 011016 011018 Recall 010830 o0001L 010831 ie 011014 011016 011018 To be able to scroll in the folder list press the key once and then use the verRTI 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 key and locate the file in question by means of the VERTICAL CURSOR keys Press ENTER to recall the located file setup and exit to leave the menu without re calling any file setup The menus for clearing files folders and the entire memory Clear file CONFIRM CUR F ILE Clear file CANCEL SELECT CUR DIR
136. ssocteedens 40 De Chie which FUNCTIONS C0100 sorrire n 40 Copr ihe setini to PT A Ce uanear Cer eer peer EE tre ery err 41 PS CITI A TCS OUR E tasssn eaten sans E T 41 Meaning At NAN CEE mode csieiicintessdaveatnsienisonceicaagmasenusicisonivaldsatdnsateaieeig 43 Displays thetuncthons CAS OTC crus sais ies sorenteansenenesiucasesnseteaesieatiansctacartes 43 Hechler G1 soap 9 Ocal LO as Tine eee ee ene eee ee eee er 43 Adding markers to a measurement Adding markers toa Tearen iE ricana ert oe eee er ener ener 44 E A T T E E E N ees eeoe aac tees 45 Other markers inserted by the ostin me ssscsticntreescasneserscicissnistadn nan 45 E a E E EE nese eenecstiatseansanncarted 45 Multispectrum measurements Mulus peci rum measure nne o serons sorg en E 46 ooa Uy TOF TMM IE 19 1 IN atoia Erne i E 46 Units equipped with basic prole extension jp caconsuctaccsssorsisneessiusdbeadsamennaosns 46 Units equipped with enhanced profile Extension asicsaescecsssiesnivatcsstcnsamaius 46 Norsonic Nor118 ix User Guide Makine multispect rir Measurements sissors 47 M St AB E A A E 49 Chapter 10 Reverberation time measurements MV Tt E e E N E A E 52 E SUM E E E A E eannaies 52 How we measure the reverberation UMC pags sscactescracessneseeisinasorssieucceneadeedenss 53 aE a o a E A E eo E E E EE Eye PjCASUSQUATS TE erenneren nO EEE EE R J3 Minimum reverberation times PossiDle ssnin e 54 Making reverberii on Meremees npn R 55 O TE 1 a E E E oy Recalling a S
137. stantaneous e Maximum Fr time weighted sound pressure level e Minimum Fr time weighted sound pressure level e s time weighted sound pressure level instantaneous e Maximum s time weighted sound pressure level e Minimum s time weighted sound pressure level e 1 time weighted sound pressure level instantaneous e Maximum I time weighted sound pressure level e Minimum 1 time weighted sound pressure level e Integrated averaged sound pressure level Sound exposure level e Peak sound level Exceeding level for r time weighted sound pressure level cumulative distribution As an option the sound level meter may also simultane ously measure Integrated averaged 1 time weighted sound pressure level e 1 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 distribu tion for the F time weighted level The calculation is done for frequency weightings a and c or z and for 1 1 octave or 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
138. 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 r k The line denotes eis ee a periods are 14o A A Leq 42 8 marked When you later press PAUSE 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 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 ambigous 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 youve 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 100 ms Between 100 ms and 1 s the resolution is adjustable in 25 ms steps Above 1 s 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 r
139. structure The memory structure of the Nor118 is quite similar to that of a pc They both have folders and files However simplicity is a keyword in the Nor118 memory handling the folder available for storage has the name of today s A memory structure metaphor eee yy Today s date File No 9999 s 03 File No 00 File No 0002 Ls File No 0001 Memory date and the files are numbered consecutively in ascending order as they are stored starting at 0001 Memory size The size of the part of the Nor118 internal memory intended for storage of measured data is approximately 5 megabytes This is a number which says more or less noth ing 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 Ihe memory can hold more than 10000 global measurements with all available global functions and distribution when frequency analysis has been deac tivated Example 2 The memory can hold more than 2 500 global measurements with all available global functions and dis tribution when frequency analysis has been activated Example 3 The memory can hold approximately 2 500000 samples of L t when only one function is logged requires the enhanced profile extension This corresponds to more than 60 hours logging with 0 1 s resolution Example 4 The memory can hold more than 90 000 samples of
140. struments are in general as stable as the sound calibrators However measuring microphones are very delicate devices designed to fulfil very rigid specifications This makes them vulnerable and subject to damage 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 instru ments The Nor118 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 Nor118 should preferably take place before a measurement session is commenced or when ever required by applicable standards If you know the microphone cartridge sensitivity you may key this in using the NUMERICAL KEYPAD However doing so will never replace calibration with a sound 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 Nor118 has a 120 dB dynamic range 10 130dB SPL the 80 dB bar graph range is a display limitation only Hence you won t have to bother with setting the full scale before you enter the Calibration menu Furthermore since the Nor118 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 s
141. surement period length e Profile resolution required if applicable e The need for frequency analysis and bandwidth if applicable e The functions to be measured requires extension 5 and or 7 The need for statistics if applicable The type of outdoor microphone unit for semi perma nent or permanent installations e Adaptors needed if applicable e Cabinet or casing required for the sound level meter e 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 download acquired data The setup of Nor118 will be found in this manual while all the accessories can be found in a separate leaflet or on Www norsonic com NN Transfer of data toa PC T TRANSFER MEASURED DATA from the Nor118 to a pc you will need a Norl441 cable available separately contact your local representative or the factory To transfer measured data via a modem you will need a Nor1489 cable for Gsm modems and Nor1490 for conven tional modems Both cables are available separately An easy way to transfer data to a Pc is by means of the software program NorXfer available separately The instrument can also be controlled from remote For a complete list of remote control commands contact your local representative or the factory N Pin out of the ca
142. suring the sound power 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 1503746 the environmental correction factor K is obtained from this graph by enter ing the abscissa with the appropriate value of A S ao 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 I 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 om both ceilings and walls 0 5 Room with large amounts of acoustical material on ceiling and wall 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 A axS in which S is the total area of the surfac
143. t 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 by you Norsonic Nor118 User Guide The measurement time elapsed counter will be updated to reflect the back erase Note that the statistics buffers optional extension will be updated similarly Displaying the functions measured The instrument measures the SPL Lax LMIN Leq LE and the Lpgax Note that the SPL Lmax and Lu are all measured with the selected time constant while the rest do not make use of the time constant at all During measurements the sp value is updated every second Once the measurement is over the sPpL becomes meaningless A single spL value cannot be used to char acterise 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 The functions are available sequentially To display a certain function press the FUNC key repeatedly until the function appears The sequence is as follows Leq gt Lmax E S SPL Lmin ie Lpeak q _ L e Accessible during measurement only not after 21 22 Chapter 4 Simple sound measurem
144. t be changed by the user C or Z as spectral weighting network The Nor118 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 these 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 Nor118 it extends far beyond that viz 20 20 000 Hz 0 1 dB and is well defined in an upcoming standard FDIS IEC 61672 The Nor118 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 2nd netw Chapter 4 Simple sound measurements Making a measurement To start a measurement e Press the sTarT key The R in the display indicates that a measurement is running To temporarily halt an ongoing measurement e Press the pausE conr key To resume a paused measurement e Press the pausE contT key again Upon resuming the instrument will go on measuring until the total measure ment time elapsed equals the preset duration Observe that data acquired the ten seconds immediately preced ing the pause will be erased because of the back erase function see
145. the instrument must display the percentiles table In the percentiles table press the x 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 gt end right key The corresponding percentile value will now be displayed given that the measurement duration was long enough to provide a sufficent number of samples Using ENTER will not work here The user defined setting applies to every frequency band They cannot have individual settings 33 34 Chapter 5 Frequency analysis Storing the acquired data The Nor118 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 The structure of the Nor118 is very simple the folder 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 9998 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 key The display w
146. tiles table will fail to produce values for all percentile settings unless the meas urement 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 you should set the resolution to the same value as the dura tion to avoid that the instrument starts 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 Instruments equipped with the Multispec L Z trum extension option 8 may also log the spectrum as a function of time This is treated in chapter 9 Multispectrum measurements Cf Basic time profile measurements Enhanced time profile measurements and Multispectrum measurements for details on logging the 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 extension 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 The time constant is used for the spL the Lmax and the Lm measurements but neither Leq nor Lg 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 Lm
147. to expand the measurements to also include the time profile is to define the time resolution To define the duration and the resolution 1 Press setup gt 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 Navigate and leave the menu as usual If you ve set up a profile resolution different from i e The effect of pressing stop before resuming If you terminate an ongoing measurement 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 shorter than the global measurement duration the instrument will log the time profile in addition to the global measurement To start the time profile measurement e Press START To switch to see the time profile e Press the XA key To return to global mode press the key again Since the profile is an add on to the global the features available while measuring described in the chapters Simple sound measurements and Frequency analysis apply even here q Functions measured in the basic time profile mode In the basic time profile mode the instrument logs the a weighted equivalenmt level the a weighted maximum sound pressure level and the z or c weighted peak lev
148. tored Mie ASU eM AE uninin ET oY Makine another geter F104 ci 001 os 41 ee rene e TT a arene cnet tr ey errr 57 Leaving the table rernm to TEA Y MOE wwecspsescescorscarsepaciestarss iewictegnianidonss of Chapter 11 About sound power measurements About SONG power Meduro mene ioana R ES 58 Hore ee aca Nd eh ag paralelepiped sr E 59 Flemispherical measurement GUIlACe sirine 59 Hemispherical microphone POSITIONS siacigasiendacesute seas custestessedisicdivieeoednadens 60 Additionil microphone pos WioNS iesse teneerne aares ee En Cert eter ete tear e 60 Parallelepiped measurement Suria Gispen aa 62 Merpione po oO eea E R E E 62 Additional microphone POS ONS sssrssrieseiesmesriissisiissssisssriesrin oeo 62 Reducing the fl mBEr OF POSINONS esre an 63 Mirpo itoi one eMC ola Me ssogra 63 More tmnone releci ar Pl ANE neier R 63 Chapter 12 Sound power acoustic environment requirements Sound power ACOUSTIC environment requirements ssisscisdssresrcessoeansnecstercare 65 S a a A A A EE 66 The kos PACE OL eaa EE 66 X Contents Chapter 13 Chapter 14 Chapter 15 Chapter 16 PR ONL TAN O tetera ste ecu es tines E E east eanneceansee 66 Usine reverberation TE TASEI aopa E 67 Test room qital ication TEQUIEMENES orrera ai 67 Measuring the sound power Measuring the SOMME DOWEL isorinis rreran E 68 Makino Ne AU 10 10 a E R totum Ame gaat 68 Darkar TONGS peach cternes seated E E E E S 68 VSG EE GA UE E E a E E E 71 DOUNG Power Resule serenite
149. vel 98dB 137dB 138dB 136dqB 133 qB Lower level 24dB 24 dB 24 dB 24dB 24 dB Ref level test 94 qB 114dB 114dB 114dB 114 qB The primary indicator range for compliance with 1Ec 60651 type 1 is 24 dB to 117 dB For compliance with 1Ec 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 5 Hz 1 kHz 4 kHz 8kHz 12 5 kHz Upper level 134 qB 137dB 136dqB 134dqB 131 qB Lower level 30dB 30dB 30 qB 30 qB 30 dB Ref level test114 qB 114dB 114dB 114qB 114 qB Total range for measurement of Z weighted levels The linear operating range is identical to the total range Frequency 31 5 Hz 1 kHz 4 kHz 8kHz 12 5 kHz Upper level 137 daB 137dB 137dB 137dqB 137 dB Lower level 40dB 40dB 40dB 40dB 40 dB Ref level test114 qB 114dB 114dB 114dB 114 qB 85 86 Chapter 18 Technical specifications Measurement range for C weighted peak levels Frequency 31 5 Hz 1 kHz 4 kHz 8 kHz 12 5 kHz Upper level 137 dB 140dB 139dB 137dB 134dB Lower level 45dB 45dB 45dB 45dB 45 dB Ref level test114 qB 114dB 114dB 114dB 114dB Power supply Battery 4 cells 1EC LR6 AA sized ALKALINE batteries are recommended e g DURACELL ULTRA M3 AA sized NiCd or NiMH rechargeable batteries may be used but must be charged outside the instrument Battery voltage and time on battery since last change of batteries a
150. what to print by what you display by the time you press the PRINT key This means that to print Norsonic Nor118 77 User Guide the spectrum you must display the spectrum on the screen to print the profile you must display the profile and so on NV Two printout examples a profile and a sound power meas urement output ruz Scale K 8o oa i acta A P 26 pa Tim Conet F Period 125 ms Rei Time O M AF SPL A Leq AF Max C Peak 0 00 000 37 7 37 8 37 7 63 93 0 00 125 37 6 37 6 37 7 BA A O 00 250 37 3 lt 37 7 63 1 0O 00 375 37 0 36 9 37 4 62 B 0 00 500 37 4 37 4 37 4 6S S 0O 00 625 a if ral Stat 37 6 64 4 0 09 000 41 2 ce PRS 42 9 63 1 CeO 212s 41 4 41 1 41 4 14 3 0 09 250 44 5 45 9 45 4 69 3 Norsonic AS Sound Power Measurement According to ISO 3746 EN 23746 Page 1 of 2 General Information and Overall Results Sound source Manufacturer Dimensions 1 Technical data Test conditions Operating conditions Location of sound source in test environment Multiple sources Acoustic environment Test environment Wind speed Acoustical qualification of the test environment Instrumentation manufacturers Instrument Norsonic AS E ses hh Ser Nor Preamplifier Norsonic AS PENO C 1o is PRES Microphone Ser No Windscreen Characteristics Calibrator Acoustical data Measurement surface Parallelepiped on three reflecting planes Reference box Length 1 00 m Reference b

Nor-118 User Manual - Campbell Associates

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