1800 Sound Level Meter User Manual
Contents
1. Figure 28 Block Diagram of Model OB 300 44 XVII ADDENDUM FOR THE MODEL 1800 5 The Model 1800 5 Integrating Sound Level Meter is a special purpose integrating meter with an exchange rate of 5dB This instruction manual is written for an exchange rate of 3dB This addendum lists the changes in this instruction manual to make it compatible with the 5dB exchange rate meter They are as follows 1 Wherever the model number 1800 appears this is replaced with 800551 2 Both LEQ and SEL function on a 5dB Exchange Rate Replace LEQ with LEQ 5dB and SEL with SEL 5dB 3 Note that Figure 5 Sample Printout values were obtained for the 3dB system 4 SPECIFICATIONS under Standards All IEC 804 1985 specifications related to 3dB LEQ and SEL are no longer relevant The meter performs all tests properly under a 5dB exchange rate that is not included in this standard When measuring noise in the SPL Mode a 3dB and 5dB exchange rate meter will read essentially the same When measuring steady non fluctuating noise in the integrating mode both the 3dB and 5dB exchange rate meters will read essentially the same However when the noise is of the impulsive fluctuating variety the 5dB exchange rate meter will tend to read LEQ 5dB and SEL 5dB somewhat lower than the 3dB exchange rate meter 45 XVIII DOWNLOADING INSTRUCTIONS Connect the meter to the computer using cable 59 749 for2. instructions for Model 1800 Precision Integrating Sound Level Meter and Model OB 100 Octave Band Filter and Model OB 300 1 1 1 3 Octave Band Filter Note Due to the new ATEX Directive in Europe all references in this document to Ex or EEx for intrinsic safety approvals should be disregarded effective 7 1 03 within the member countries of the European Union EU At this time this product is not approved in accordance with the new ATEX Directive and is not sold for use in hazardous atmospheres or explosive zones by customers within the EU Outside of the EU all references to intrinsic safety continue without change 59 332 Rev C 5 97 II ELE Iv vI VII G TABLE OF CONTENTS MODEL 1800 PRECISION IMPULSE INTEGRATING SOUND LEVEL METER WITH THE OB 100 0B 300 INTRODUCTION TO THE MODEL 1800 A Assembling the Meter Microphone Handling and Storage ABOUT THE METER A The Display B Meter Controls Ov Ou EX In Pr CHEC HOLD Button RESET Button RUN Button PRINT Button BATTERY Button RESPONSE Switch WEIGHTING Switch MODE Switch dB RANGE Switch POWER Switch erload Detection tput Jacks PRINT DC AC DATA ternal Filter Connector ternal Switches Mic Polarization Baud Rate Display Time intout KING THE METER INTEGRITY A Battery Check B AOAQWY 1TAOQWP TOA Ca GENE Me Ba Wi Ch Da libration RAL OPERATIN
3. AUTO Filter Operation Place the meter into the Pause mode using the RUN Pause button Press RESET to clear all internal memory Select the first frequency of interest Be sure that the TIME adjustment is set to the desired filter cycle time Slide the filter POWER switch to AUTO To start the sampling sequence place the meter into the RUN mode and immediately press the proper direction button The UP ARROW button causes the frequency to cycle to the next higher frequency the DOWN ARROW button causes the frequency to cycle to the next lower frequency When the last frequency of interest has completed its cycle time slide the filter POWER switch to MANUAL and immediately place the meter into the Pause mode NOTE If it is necessary to record all 10 frequency bands exit the AUTO mode while in the last frequency band Use the MANUAL Filter Operation to obtain the last frequency Otherwise the first frequency will be written over C Reviewing the Data To review the data the meter must be in the Pause mode Use the Up Down buttons on the filter to review the frequencies that were measured Each frequency has the following information in memory SPL MAX MIN SEL TIME and LEQ If an overload occurred during any frequency band measurements the OL indicator will appear in the display OL time can then be recalled by first placing the mode switch into the TIME mode and then holding the BATTERY button down NOTE Any
4. Finger tighten the black locking ring by screwing it onto the meter Il ABOUT THE METER A The Display he LCD display contains both a numeric readout and a bar indicator along ith BAT battery RUN HLD hold and OL overload indicators The rate t which the numeric display is updated depends upon the setting of a switch ocated in the battery compartment Either a one second or a one quarter econd display rate can be selected m Hwg he bar indicator portion of the display will indicate the current SPL Sound ressure Level except when the BATTERY button is pressed See III A attery Check When using the bar indicator for SPL the 0 to 60 range of he bar indicator represents the selected range on the Range switch If on he 80 to 140 range for example the bar indicator represents 80 to 140 dB ttwUuw he MODE switch selects what data is to be displayed in the digital portion f the readout i e SPL MIN MAX etc Sound levels are shown to the earest 0 1 dB RUN time or OL time is displayed in MIN SEC if the total ime is less than 20 minutes and in HRS MIN if the total time is greater han 20 minutes et a Oa B Meter Controls HOLD Button When the HOLD button is depressed the current value in the numerical portion of the display is frozen and the HLD annunciator appears in the display If the meter is in the RUN mode while or prior to pressing the HOLD button the last stored values of MIN MAX SEL TIME a
5. filter to the sound level meter Figure 26 shows the pinout for the filter connector x IV GENERAL OPERATING 16 0 0 1 GND PROCEDURE AS VIEWED INTO 17 oa 2 GND the moge PILTER CONNECTOR jg o O 3 SIG IN FROM METER OUTPUT 1800 300 a oO EA i Octave 0 0 dar cab si o a z FREQUENCY CODE Fai CTO METER Analyzer 22 0 0 7 D is made up 23 00 8 E of the e4 0 0 9 F Model 1800 25 0 0 10 BLANK DUT TO METER Precision 26 O O 11 SIG OUT TO METER Impul se 27 OO 12 1D OUT TO METER aoa 28 0 0 13 65 V FROM METER g rr ie 29 00 14 65 V FROM METER p 30 0 0 15 ON OFF TO METER the 1 3 Oc F i CWO are The Meter and Set OB 300 174 tave Figure 26 OB 300 External Filter Connector Located on Top of lter Filter The units connected together with the long captive screw provided with the filter General Operating Considerations for the Model 1800 are basically the same when using the Model OB 300 with the meter 39 A Operational Check The Model 1800 should be calibrated as outlined in Section III of the meter section Checking the Meter Integrity B Calibration while the OB 300 is OFF The OB 300 has a fixed input to output voltage ratio of approximately 1 0 dB at each center frequency and requires no adjustment After the meter is calibrated check the filter for proper ope
6. linearly represented by a 0 to 1 volt DC output Zero volts is equal to the bottom of the range and 1 volt is equal to full scale This output is primarily provided for connecting to a 0 to 1 volt input chart recorder or data acquisition device See IV D Chart Recording and Figure 8 Chart Recording of SPL AC This jack furnishes an amplified SPL either weighted or unweighted depending on the WEIGHTING switch setting The full span of 60 dB is represented between 3 16 millivolts and 3 16 volts RMS DATA When the Model 1800 is in the RUN mode an SPL reading will be serially transmitted through the DATA jack at a rate of 16 times per second To make use of this function the meter range switch must be set in one of its two highest positions The data is an 8 bit signal proportional to the integrated sound level for the last 1 16 second The signal is normally at 6 5 volts If the meter is in the RUN mode data is sent as in Figure 3 Signal description is as follows The signal goes to 6 5 volts every 0 55 msec If the bit is a 0 it will return to plus after 0 1 msec If the bit is a 1 it will return plus after 0 45 msec The signal is sent least significant bit first The resolution is 3 8 dB All O s 30 dB if the meter is set to the 60 12 50 dB if the meter is set to the 80 14 All 1 s 30 dB 95 6 dB when set to the 60 120 50 dB 95 6 dB when set to the 80 140 The example shown in Figure 3 is 1010
7. 36 AUTO MANUAL OFF ON OFF DOWN VL uP n ASTART 090 MANUAL AUTO SEQUENCING CIRCUIT POWER BLANK SUPPLY SIGNAL FREQUENCY INDICATORS POWER SUPPLY 65V IN 6 5V IN 6 5V SWITCHED 6 5V SWITCHED TIME 0oB 200B ORDER 3 OdB 200B PROGRAMMABLE GAIN OCTAVE CIRCUIT FILTER SIGNAL SIGNAL INPUT OUTPUT INPUT OUTPUT Figure 25 16 fc Q 0 TO CIRCUITS oO A med oa i o0 0 t o 0 Le wo AS VIEWED INTO FILTER CONNECTOR GND GND SIG IN FROM METER bo Frequency CODE CTO METER BLANK QUT TO METER SIG OUT TO METER LD DUT TO METER 6 5 V FROM METER 6 5 V FROM METER ON OFF TO METER Block Diagram Model OB 100 Octave Filter 37 XII INTRODUCTION TO THE MODEL OB 300 The Quest Model OB 300 1 3 1 1 Octave Filter is a plug in module containing a selectable set of filters The OB 300 meets the most stringent requirements of ANSI S1 11 1986 and IEC R225 1966 for octave and third octave band filters The unit contains 33 selectable filter frequencies from 12 5 Hz to 20 kHz when in the 1 3 mode and 11 selectable filter frequencies from 16 Hz to 16 kHz when in the 1 1 mode It may be operated in either the manual or automatic mode Primary uses include frequency analysis for product noise emission material acoustics community noise audiometer calibration and analysis of audiometric roo
8. Figure 5 Sample Printout OL TIME 14 04 00 06 III CHECKING THE METER INTEGRITY A Battery Check At any time except during PRINT the BATTERY push button can be pressed to get an indication of battery strength The weaker of the two 9 volt batteries is shown on the bar indicator of the Model 1800 s display Good batteries will be indicated with the bar extending well beyond the indicating arrow 5 on the 0 60 scale If the bar falls below the indicating arrow then BOTH ALKALINE batteries must be replaced Because erroneous readings will occur if the battery check registers below the indicating arrow it is good practice to perform a battery check before using the 1800 Collected data and output port signals are NOT affected by performing a battery check B Calibration To check the calibration of the Model 1800 perform the following procedure using a Quest Calibrator ll ss Perform a battery check 22 Turn the Calibrator ON to produce the level specified on the label at 1 kHz If the Calibrator can produce 94 dB it is the preferred level to use 3 If an adapter is needed to mate the microphone size to the calibrator coupler insert it fully into the calibrator 4 Place the Calibrator with adapter if used fully onto the microphone Die Set the Model 1800 to LIN SLOW or FAST the SPL mode and the 60 120 range if using a level of 94 dB 6 Use a small screwdriver to adjust the calibration p
9. IEC 651 1979 Type 1 I and IEC 804 1985 Display 3 1 2 Digit Liquid Crystal Display with an additional Quasi Analogue 60 dB indicator in 2 dB increments Level display indicates to 0 1 dB resolution Time display indicates either Min Sec or Hr Min Annunciators are included for Battery Check Hold and Overload Indication Printout When used with a printer a one page printout is produced Ir consists of the following Heading WEIGHTING and RESPONSE settings LEQ MAX MIN and SEL levels RUN TIME and OL TIME EXCEEDANCE LEVELS dB with 1 dB resolution and Filter Data for each frequency LEQ MAX MIN and SEL along with the RUN TIME and OL TIME for each frequency Modes of Operation Sound Pressure Level SPL Maximum Level MAX Minimum Level MIN Sound Exposure Level SEL and Equivalent Level LEQ Peak Level PEAK and Impulse Level IMP can also be measured Minimum Measurement Meter only With Model QE4146 Microphone 27 dBA Using Linear Weighting with an Octave Filter Set See Figure 17 The minimum measurement varies depending on the filter frequency selected Maximum Measurement With Model QE4146 Microphone 120 dB with 20 dB Crest Factor 140 dB if measuring a sinusoidal signal Overload indication will occur if upper range is exceeded Frequency Weighting Networks A B C and Linear When using a filter set any one of the weightings may be selected Meter Response Slow Fast Impulse and Peak
10. NL 15 micro plug to the 3 5 mm DATA jack on the meter Quest Part Number 59 748 1800 2800 to NL 15 Cable Qi Turn ON the NL 15 and RESET it 3 Press the RUN button on the meter 4 After sufficient data is accumulated press the RUN button on the meter to enter the Pause mode Su Connect the NL 15 to a printer and print the data The setting of the remainder of the switches and push buttons will not affect the data stored in the NL 15 MODE HOLD PRINT and BATTERY will not change the data stored If RUN on the meter is toggled off the NL 15 will accumulate null data If toggled back on it will accumulate additional data If an octave filter is connected to the meter when used with the NL 15 the NL 15 will accumulate the filtered data To obtain data on multiple filter bands print out the data after each filter frequency and then reset the NL 15 The weighting in the summary will of course be wrong since the filter is now in series with either A B C or LIN V TECHNICAL INFORMATION A Principles of Operation The Quest Model 1800 utilizes low noise low power analog and digital integrated circuitry to ensure long battery life maximum stability and superior reliability over a wide range of environmental conditions Figure 9 is a block diagram of the Model 1800 s internal circuit operations 17 18 MICROPHONE 17 17V Ds SIGNAL PREAMP SIGNAL gl Ac iypyT be MODEL 1800 PREAMP GND CONNEC
11. S1 11 1986 and IEC R225 1966 for octave band filters The unit contains ten selectable filter ranges from 31 5 Hz to 16 kHz center frequencies with full octave band width Primary uses include frequency analysis for product noise emission material acoustics community noise audiometer calibration and analysis of audiometric rooms Active filters are employed throughout the Model OB 100 thus permitting the unit to have both high accuracy and compact size VIII ABOUT THE FILTER A Filter Controls POWER Switch A three position slide switch that does the following OFF Disconnects the filter circuitry from the attached sound level meter With this switch in the off position the OB 100 does not use power from the meter batteries MANUAL Filter frequency selection is performed with two push buttons START Buttons AUTO Unit automatically cycles through the desired filter frequencies while storing sample information for each frequency during the RUN mode START Buttons Allow the user to cycle through the different bandpass filters The two buttons allow manual frequency control in MANUAL Mode or frequency direction control in AUTO Mode 20 dB Button When this button is depressed the output of the filter is amplified by exactly 10 times 20 dB and then fed back to the sound level meter Therefore 20 dB has to be subtracted from the meter reading when using this button TIME A screwdriver adjustment to control the automa
12. The Peak onset time constant is less than 50 microseconds Peak measurements may be made in either A B C or Linear Weighting Microphones Removable precision 1 2 inch prepolarized condenser electret microphone is standard Optional 1 2 inch one inch and other microphones are available Preamp Removable The input impedance is greater than 1G ohm in parallel with 2 pF The preamp will drive up to 100 feet of cable with no loss See Figure 14 Polarization Regulated 200V DC within 2 when using condenser microphones The voltage must be manually switched off when using prepolarized condenser electret microphones 28 Meter Input The input impedance is 1 Megohm in series with 0 1 MFD The maximum sinusoidal input voltage is 10V RMS AC Output 3 16 V RMS at full scale 60 dB 3 8 V RMS maximum The output impedance is 3 2K ohms Connected equipment should be at least 10K ohms The output can be shorted without damaging the meter or changing the meter reading DC Output 0 to 1 00V DC 60 dB span Each 0 167V change equals 10 dB Connected equipment should be at least 10K ohms The output can be shorted without damaging the meter or changing the meter reading Print Output Serial output to printers or computers using RS 232 voltage levels Selectable baud rates of 300 600 1200 or 2400 ASCII character format Data Output Output transmission of real time digital data occurs at a rate of 16 times per se
13. enter frequency and requires no adjustment After the meter is calibrated heck the filter for proper operation as follows qaaqaevaBgH 32 1 Read the calibrator 1 kHz output level Set the meter dB RANGE switch so that the calibrator level will indicate within the upper 20 dB of the meter display Set the RESPONSE switch to FAST WEIGHTING switch to LIN and MODE switch to SPL Turn the POWER switch to ON 2 Set the OB 100 POWER switch to MANUAL and press the RUN button to place the meter into the RUN mode Then use the two direction buttons to select the 1 kHz filter 33 Place the calibrator and adapter if needed onto the microphone Turn the calibrator ON A meter reading that is very close to the level listed on the calibrator should result An error of 0 5 dB is acceptable This is due to the center frequency filter tolerance of 0 5 dB maximum 4 Change the OB 100 filter frequency first to 500 and read the display Then change to 2k and read the display At both frequencies the readings should be 19 to 23 dB less than the 1 kHz calibrator level Bo Change the OB 100 filter frequency to 1k and the meter dB RANGE so that the meter reads 20 to 40 dB less than full scale Press and hold the 20 dB button on the OB 100 The meter reading shall rise approximately 20 dB to verify that the 20 dB button functions 6 Remove the calibrator The analyzer is now ready to use B Taking a Measurement Fs Turn
14. the meter POWER switch ON The meter will come on in the Pause mode Perform a BATTERY test to verify that the analyzer has sufficient battery power Replace the batteries if the bar indicator falls below the indicating arrow located at 5 on the 0 60 scale 2 Set the dB RANGE switch to 80 140 dB Set the RESPONSE switch to FAST WEIGHTING switch to LIN see note below and the MODE switch to SPL NOTE Note that the filter response can be in series with either A B C or LIN This is the operator s choice However LIN is generally used when taking octave band measurements 32 Turn the OB 100 POWER switch to MANUAL to activate the filter will appear in the display with the meter in the Pause mode 33 34 4 Select the desired WEIGHTING and RESPONSE Then change the dB RANGE switch down in 20 dB steps until the OL indicator flashes or stays on Then go back up 20 dB so that the OL indicator stays off This ensures that the AC input to the filter is at its maximum voltage without clipping overloading MANUAL Filter Operation Place the meter into the Pause mode using the RUN Pause button Press RESET to clear all internal memory Select the first frequency of interest Then enter the RUN mode for the required amount of time necessary to obtain a valid sample Then enter the Pause mode change to the next frequency of interest and enter RUN again etc Repeat this process for all frequencies of interest
15. 104 103 101 100 98 97 95 L40 94 93 92 91 91 90 89 89 89 88 L50 88 88 88 88 88 88 88 88 88 88 L60 88 88 88 88 88 88 88 88 88 88 L70 88 88 88 88 88 88 88 88 88 88 L80 88 87 87 87 87 87 87 87 87 87 L90 87 87 87 87 87 87 87 87 87 87 MODEL OB 300 1 1 1 3 OCTAVE FILTER SET SERIAL NO FREQ Hz LEQ dB MAX dB MIN dB SEL dB RUN TIME 12 5 86 9 87 7 86 6 96 8 1 00 09 16 103 1 105 7 95 6 112 2 2 00 08 20 112 2 113 2 110 6 119 2 2 00 04 25 103 9 109 4 98 6 110 1 2 00 04 31 5 89 5 95 2 82 1 95 3 00 03 40 76 8 85 8 66 3 86 3 2 00 09 50 76 8 77 9 76 4 81 5 2 00 03 63 93 9 94 8 92 6 98 0 2 00 02 80 112 1 113 2 110 2 120 5 2 00 06 100 105 0 109 1 100 8 109 0 2 00 02 125 90 6 97 1 80 9 97 2 00 04 160 13 5 80 6 66 3 83 1 00 09 200 76 7 717 6 76 1 80 4 2 00 02 250 95 8 96 7 94 4 98 3 2 00 01 315 116 0 120 3 107 9 129 3 2 00 21 400 100 6 103 8 96 7 103 5 2 00 01 500 89 5 92 9 85 4 92 4 2 00 01 630 72 8 81 7 61 8 82 8 2 00 10 800 741 71 9 70 4 75 4 00 02 1 000 89 7 90 7 88 4 93 5 2 00 02 1 250 106 8 107 9 105 7 110 0 2 00 02 1 600 99 6 103 8 94 4 103 4 2 00 02 2 000 82 6 90 7 67 8 91 2 2 00 07 2 500 63 4 65 6 61 8 66 4 2 00 02 3 150 83 0 88 4 49 4 96 2 2 00 20 4 000 90 4 91 4 89 2 94 3 2 00 02 5 000 105 8 106 8 104 6 108 8 2 00 02 6 300 100 3 102 3 97 8 101 0 2 00 01 8 000 91 1 94 1 87 7 93 0 2 00 01 10 000 77 4 83 9 66 7 84 0 2 00 04 12 500 64 5 67 4 61 1 67 2 2 00 01 16 000 84 2 90 7 50 6 92 3 1 00 06 20 000 101 9 107 2 86 9 117 5 2 00 37
16. 1100 binary The level is 172 x 3 8 50 114 5 dB when on t 0 dB range 0 dB range dB range dB range 172 decimal he 80 140 dB range l 0 1 E External orite 55 55 55 55 55 55 j 55 Connector 0 0 1 1 0 The 30 pin connector on the le 45 bottom of the meter Figure 3 Data Jack Format is used r connecting either the Model OB 300 combination 1 3 1 1 Octave Filter Set or the OB 100 Octave Filter Set Refer to section XIII for details regarding this connector F Internal Switches accessible to the user Refer to Figure 4 Mic Polarization The small ON OFF switch on the the 200 volt microphone polari for condenser type microphones There is an internal switch located in the battery compartment that is right hand side operates zation which is necessary Baud Rate Actuators 1 and 2 of the dip switch located through the hole in the lower left control the baud rate at which the meter transmits data to available are 300 600 1200 a printer Baud rates and 2400 Display Te CAUTION The USE 9 VOLT ALKALINE BATTERIES ONLY reces NEDA 1604 OR EQUIVALENT sed dip switc h contr ols the rate a E which the 25 SECOND displ a y updat Figure 4 Battery Compartment Internal Switches es The options are 1 0 second or 0 25 second G Printout The Sound Level Meter produces a hard copy of the information accumulated during the tota
17. 30 1986 zag 50 DOWN TIME MODE P TLA sTaRt YIL S OolB 200B r Order 3 r Type 2 RELATIVE TRANSMISSION LOSS oB 60 1 1 F3 g rE ype C and IEC R225 1966 Figure 27 Center Frequencies 1 1 Mode Frequency Selection F 70 Sub t oi 015 02 03 04 06 08 1 1s 2 3 4 6 8 10 FREQUENCY RATIO F f Typical OB 300 Filter Response 1 3 Mode 33 frequencies from 12 5 Hz to 20 kHz 11 frequencies from 16 Hz to 16 kHz Full manual control or automatic sequential stepping through each frequency Power Source Size 3 3 x 4 2 Weight 9 ounces Sound Level Meter x 1 8 inches 84 x 107 x 47mm 255 grams 43 auTO MANUAL AUTO ORDER 3 0dB 200B MANUAL SEQUENCING PROGRAMMABLE GAIN CIRCUIT OCTAVE CIRCUIT oreo FILTER POWER BLANK Sona oo SIGNAL SIGNAL INPUT OUTPUT INPUT OUTPUT AS VIEWED INTO FILTER CONNECTOR we Ni FREQUENCY HO O GND INDICATORS v Ga D HO SIG IN FROM METER aa i a AS m s FREQUENCY CODE O0 C TO METER m D eo 4 ee ae 1 BLANK OUT TO METER ON OFF TO CIRCUITS Oo SIG OUT TO METER POWER 4 1D DUT TO METER SUPPLY 6 5V IN j 0 0 65 V FROM METER 6 5V IN Htt 65 V FROM METER 6 5V SWITCHE Dj O ON OFF TO METER 6 5V SWITCHED j NS
18. 800 also stores the length of time that the OL condition existed during the RUN mode If an OL condition occurs while in the RUN mode the OL indicator will come on and remain on until RESET is pressed The time duration of the overload condition can be viewed by sliding the MODE switch to TIME and then holding the BATTERY button in The overload time will also be printed on the hard copy printout Note OL can be reset for use in the SPL mode without losing accumulated data Place the meter into PAUSE slide the RESPONSE switch to PEAK and then press the RESET button Then return the RESPONSE switch back to the desired position OL is now reset for normal use in the SPL mode only It still remains latched when switched back to either the SEL TIME or LEQ mode D Output Jacks y0 BUSY All output jacks use a 3 5 mm stereo No A PRINT See Figure 2 The following plug describes each output function GROUND PRINT Pressing the PRINT button PRINT JACK causes serial ASCII data to be transmitted from the print jack at appropriate w U NO CONNECTION RS 232 levels This data may be sent to a serial no 2 SIGNAL printer or a computer The baud rate is GROUND determined by two switches located in the battery AC DC and DATA JACK compartment See Figure j 4 Battery Compartment Figure 2 Output Jack Connections Internal Switches for switch settings Dc The Sound Pressure Level SPL over the 60 dB range selected is
19. G CONSIDERATIONS ter Microphone Placement ckground Noise nd Screen Effects art Recording ta Logging with the NL 15 TECHNICAL INFORMATION Pr Mi Pr Mi In We In Re SPEC inciples of PER ERETON crophone eamplifier Input Characteristics crophone Preamp Extension Cables put Buffer Circuitry ighting Characteristics ternal Electrical Noise sponse Charts IFICATIONS INTRODUCTION TO THE MODEL OB 100 PRR MAMAINAAANDADADGDGADVUUOFP SP HP BWW WWWDN DY ooo VIII ABOUT THE FILTER A Filter Controls POWER Switch START Buttons 20 dB Button TIME ae B Filter Connector IX GENERAL OPERATING PROCEDURE A Operational Check B Taking a Measurement MANUAL Filter Operation AUTO Filter Operation C Reviewing the Data X TECHNICAL INFORMATION XI SPECIFICATIONS XII INTRODUCTION TO THE MODEL OB 300 XIII ABOUT THE FILTER A Filter Controls POWER Switch START Buttons 20 dB Button MODE Switch TIME se s B Filter Connector XIV GENERAL OPERATING PROCEDURE A Operational Check B Taking a Measurement MANUAL Filter Operation AUTO Filter Operation C Reviewing the Data XV TECHNICAL INFORMATION XVI SPECIFICATIONS XVII ADDENDUM FOR THE MODEL 1800 5 XVIII DOWNLOADING INSTRUCTIONS A Downloading Using DOS B Downloading Using Windows QUEST SERVICE AND WARRANTY POLICY Service Policy TE Warranty Policy I INTRODUCTION TO THE MODEL 1800 The Quest Model 1800 ma
20. L indicator will appear in the display OL time can then be recalled by first placing the mode switch into the TIME mode and then holding the BATTERY button down NOTE Any frequencies that were not measured will appear as in the display when the MODE switch selects either SPL MAX MIN SEL and LEQ Both TIME and OL TIME will appear as 0 00 since no run time has elapsed XV TECHNICAL INFORMATION The OB 300 conforms to ANSI S1 11 1986 Order 3 Type 2 Sub type C and IEC R225 1966 The normalized passband characteristics of both the 1 1 and 1 3 filter responses are depicted in Figure 27 he 1 1 filters are flat within 0 5 dB in the passband with the 3 dB down oints at approximately 0 707 fc and 1 414 fc where fc is the center requency of the band chosen The fc 2 and 2fc frequencies are down by pproximately 21 dB with the decade points fc 10 and 10fc down by greater han 70 dB to MOH he 1 3 filters are flat within 0 3 dB in the passband with the 3 dB down oints at approximately 0 89 fc and 1 12 fc where fc is the center frequency f the band chosen The fc 2 and 2fc frequencies are down by approximately 0 dB OT Hy The block diagram of the OB 300 illustrated in Figure 28 traces the signal input from the Model 1800 through the filters and back to the sound level meter 42 xX V I SPECIFICAT IONS Stand ards ANSI 51 11 Typical 1 1 Octave Response Typical 1 3 Octave Response 20
21. TOR GND BUFFER pan POLARIZATION 200V 200V BLOCK DIAGRAM SWITCH KVARTA 1o AC OUTPUT E WEIGHTING fet ATTENUATOR e MIC GAIN laii NETWORK 20dB STEP ADJUST BUFFER A EXTERNAL gt BANDPASS OVERLOAD FILTER PTIONA EER OPTIONAL SWITCHES FRONT abe TA LI INTERNAL ee re Ty SWITCHES BAUD DISPLAY 1 AC DUT i o 200V 17V 17V DC OUT HIGH VOLTAGE 5 VOLT SUPPLIES 5V i ano A SUPPLIES TO RMS CIRCUIT 5V me Pe 6 5 MICROPROCESSOR 65V DATA DUT pe 5V DIGITAL 5 76 5V 6 5V 5V Lie ge IN REGULATED BATTERY SUPPLIES TEST ov 9V CIRCUIT i i ane DISPLAY eee PRINT OUT poli AND PRINT Tl DRIVER CIRCUITRY Lm PRINT wn o Figure 9 Block Diagram of the Model 1800 B Microphone The Model 1800 is designed to accept either a half inch or one inch microphone of either prepolarized electret or condenser type The prepolarized electret microphone does not require a polarization voltage If a condenser type is used then the 200 volt microphone polarization voltage must be turned on by a switch located in the battery compartment Sec II Figure 4 Internal Switches CAUTION Be
22. a 25 pin serial port or cable 59 750 for a 9 pin serial port If you have a 25 pin cable but your computer s serial port is only 9 pins then you may use a 25 to 9 pin converter available at most computer or electronic stores No other cables should be used There are four output jacks on the side of the meter you must use the PRINT jack Check which baud rate speed of data transmission that the meter is set for The baud rate is set using dip switches located in the battery compartment of the 1800 A Downloading Using DOS The MODE and COPY commands can be used directly from the DOS prompt to download the information Type the following commands at the DOS prompt MODE COMx baud N 8 2 P lt enter gt After typing the MODE command the computer should respond with RESIDENT PORTION OF MODE LOADED If the computer responds with an error message then their is a good chance that the COM port selected is not valid COPY COMx filename lt enter gt where x refers to which com port is being used typically this is COM1 or COM2 baud refers to the baud rate and must match the meter s settings filename refers to any DOS filename the user makes up After typing the COPY command the curser will move to the next line on the screen and blink If you receive an error message retry the COPY command At this point the user should press the PRINT button on the 1800 Nothing will happen on the screen until all of the information has been
23. ach frequency if the user just wishes to step through the frequencies sequentially with no delay time in between frequencies AUTO Filter Operation Place the meter into the Pause mode using the RUN Pause button Press RESET to clear all internal memory Select the first frequency of interest Be sure that the TIME adjustment is set to the desired filter cycle time Slide the filter POWER switch to AUTO To start the sampling sequence place the meter into the RUN mode and immediately press the proper direction button The UP ARROW button causes the frequency to cycle to the next higher frequency the DOWN ARROW button causes the frequency to cycle to the next lower frequency 41 When the last frequency of interest has completed its cycle time slide the filter POWER switch to MANUAL and immediately place the meter into the Pause mode NOTE If it is necessary to record all 11 frequency bands 1 1 Mode or all 33 frequency bands 1 3 mode exit the AUTO mode while in the last frequency band Use the MANUAL Filter Operation to obtain the last frequency Otherwise the first frequency will be written over C Reviewing the Data To review the data the meter must be in the Pause mode Use the Up Down buttons on the filter to review the frequencies that were measured Each frequency has the following information in memory SPL MAX MIN SEL TIME and LEQ If an overload occurred during any frequency band measurements the O
24. adapter is needed to mate the microphone size to the calibrator coupler insert it fully into the calibrator 2 Place the calibrator with adapter if used fully onto the microphone do not turn the calibrator on yet The meter shall read less than 80 dB which generates 00 volts DC out to the chart recorder Adjust the zero control on the recorder so that the pen represents a relative dB of 0 33 Turn the Calibrator ON to produce 94 dB or the level specified on the label at 1 kHz Set the 1800 dB RANGE for the highest bar graph level without causing and overload The recorder pen should rise to the correct RELATIVE dB 54 if the calibrator level is 94 dB and the dB RANGE is set to 40 to 100 A small adjustment may be needed Use the zero adjust to do this 4 Be sure to document all chart recorder settings and meter settings when taking measurements Note that any range position can be set on the Model 1800 and the 60 dB span of the meter range will always correspond to the full 60 dB range on the chart recorder Use QUEST CHART PAPER 58 653 15 E Data Logging with the 60 TAIATA TA a y go NL 15 z o PEN CAL POINT 94 dB 30 83 The Quest Ln Model tU GF NL 5 A Noise Data 30 0 Logger can N be used 20 33 with the 10 Ay Quest pi J PEN O POINT 00 Model U 800 ogoocaog00DgToOoCoOo000DIN ee RELATIVE PAPER DC OUTPUT meter the oB DIRECTION VOLTAGE follow
25. and 63 125 and 250 500 and 1K 2K and 4K 8K and 16K Figure 17 Minimum measurable SPL s for the Model 1800 using the Model QE4170 and the Model QE4146 microphones Noise Floor values were determined by substituting an equivalent electrical impedance in place of each microphone For the One Inch Microphone 56 pF Capacitor For the One Half Inch Microphone 18 pF Capacitor 24 H Response Charts Figures 18 through 22 are plots for each of the response settings of the meter They show how the meter responds to a given sinewave input of varied pulse duration SLOW RESPONSE 1000 msec time constant Figure 18 FAST RESPONSE 125 msec time constant Figure 19 PEAK RESPONSE 50 microsecond time constant Figure 20 IMPULSE RESPONSE 35 msec rise time constant with a decay rate of 2 9 dB sec Figure 21 and Figure 22 RELATIVE RESPONSE olB gt 1 0 2 05 1 2 5 10 PULSE DURATION t SECONDS Figure 18 SLOW Response 25 E ane a a Eo li RELATIVE RESPONSE dB gt Figure 19 Figure 20 PEAK Response 26 20 50 100 200 500 PULSE DURATION t MILLISECONDS FAST Response RELATIVE RESPONSE dB Figure 21 Figure 22 IMPULSE Response to Repeated Impulses PULSE DURATION t MILLISECONDS IMPULSE Response 27 VI SPECIFICATIONS Standards Meets or exceeds ANSI S1 4 1983 Type 1 and relevant sections of
26. asurement of sound levels caused by wind blowing across the microphone the use of a windscreen is recommended The wind screen will reduce wind effects and will also help protect the microphone under dusty oily or humid conditions Acoustic attenuation effects of the one half inch WS 7 and the one inch WS 3 windscreen are shown in Figure Te 1 WS 7 HALF INCH FREQUENCY RESPONSE ERROR CAUSED BY WINDSCREEN dB 1 FREQUENCY Hz Figure 7 Acoustic Effect of Windscreens 14 D Chart Recording The Model 1800 has a DC output that is linearly related to the 60 dB LCD analog bar movement as follows Analog Bar dB 0 10 20 30 40 50 60 DC Output V 00 s17 33 50 67 83 1 00 This output capable of driving up to 100 feet of shielded or twisted pair cable is intended for use with a 0 to 1 volt DC input chart recorder that has an input impedance greater than 20K ohms efer to Figure 8 Chart Recording of SPL Connect the Model 1800 to the hart recorder input with proper polarity such that the pen is on the proper ide of the chart paper with respect to time and that the pen moves in the roper direction with increasing dB level Use a 1 kHz acoustic calibrator referrably 94 dB dB level is specified on calibrator to calibrate the hart recorder as follows a o o w n w 1s Turn the meter to ON Set the meter RESPONSE to FAST WEIGHTING to A MODE to SPL and dB RANGE to 80 140 NOTE If an
27. careful not to turn on the 200 volt polarization switch if a prepolarized electret microphone is attached The microphone may be damaged The microphone screws directly onto the preamp which in turn connects directly to the meter The preamp converts the high output impedance of the microphone into a low output impedance This allows the microphone to drive up to 100 feet of cable for remote operation Typical microphones used on the 1800 include the following Model QE4146 1 2 inch free field prepolarized condenser electret 40 mv Pa Model QE4170 1 inch pressure 200 Volt polarization 50 mv Pa Model QE4160 1 2 inch pressure 200 Volt polarization 50 mv Pa Model QE4150 1 2 inch free field 200 Volt polarization 50 mv Pa Model QEF4140 1 2 inch pressure 200 Volt polarization 16 mv Pa Typical microphone response curves for the Models QE4146 and QE4170 are shown in Figures 10 and 11 respectively RELATIVE RESPONSE dB 2 100 200 500 lk 2k Sk 10k 20k FREQUENCY Hz Figure 10 Typical Frequency Response Model QE4146 Microphone 19 c Preamplifi er Input Characteri stics The input impedance of the frequency response and the microphone attenuatio n as shown in Figures 12 and 13 RELATIVE RESPONSE dB gt le 100 200 500 lk 2k FREQUENCY Hz Sk 10k 20k Figure 11 Typical Frequency Response Model QE4170 Microphone The approximate microphone capacitances for the 1 2 inch and one
28. cond using RS 232 voltage levels Frequency Range 4 Hz 3dB to 50 kHz 3dB on linear weighting meter only Subject to microphone limitations Reference Range 60 to 120 dB Range setting Reference SPL 94 dB Reference Frequency 1 kHz Reference Direction 0 Degree when using a Free Field Microphone Sound is arriving from directly in front of the microphone diaphragm A Normal Line extending from the center of the microphone diaphragm Detector True RMS Detector Pulse Range 63 dB Detector Measuring Range From 0 dB to 40 dB on the painted scale when measuring a signal with a 20 dB Crest Factor The extra 20 dB 40 to 60 on top of the measuring range produces the 20 dB Crest Factor capability Primary Indicator Range Linearity Range 60 dB The range as indicated by both the dB RANGE switch and the painted 60 dB scale Tested with a sinusoidal signal input 29 Level Linearity Inside the Primary Indicator Range It is tested on the Reference Range 60 to 120 dB with a sinusoidal input signal Tolerance is 0 7 dB referenced to 94 dB Overload Indication The display annunciator OL indicates overload on the LCD Attenuator Accuracy Referenced from the Reference Range and the Reference SPL 34 dB on the painted meter scale Within 0 5 dB from 31 5 Hz to 8 kHz Within 1 0 dB from 20 Hz to 12 5 kHz Warm up Time 30 seconds Integration Time Settling Time 1 minute when measuring a short impulse 5 se
29. conds when integrating a constant input signal Accuracy Within 0 5 dB at 25 C Within 1 0 dB over the temperature range of 10 to 50 C Temperature Range Operation Temperature Range 10 C to 50 C Accuracy over the Operation Temperature is within 5 dB Storage Temperature Range less batteries 20 C to 60 C Do not exceed the Storage Temperature Range because possible damage to the unit may result Operating Humidity Over a range of 30 to 90 relative humidity the accuracy is within 0 5 dB Do not exceed 95 relative humidity because possible damage to the unit may result Effect of Magnetic Fields A magnetic field of 1 Oersted 80A m at 60Hz produces a maximum reading of 40 dB on Linear Weighting Effect of Electrostatic Fields Negligible as long as the protection grid is kept on the microphone Batteries Two 9 volt alkaline batteries NEDA 1604A will provide approximately 16 hours of continuous operation 8 hours with optional filter set Tripod Mount A threaded insert on back of the meter accepts a standard 1 4 20 tripod mounting screw Size 3 3 x 8 2 x 1 8 inches 84 x 208 x 47mm not including the height of the preamp Weight 24 oz 680g including the preamp and batteries 30 VII INTRODUCTION TO THE MODEL OB 100 The Quest Model OB 100 Octave Filter is a plug in module containing a selectable set of filters The OB 100 meets the most stringent requirements of ANSI
30. frequencies that were not measured will appear as in the display when the MODE switch selects either SPL MAX MIN SEL and LEQ Both TIME and OL TIME will appear as 0 00 since no run time has elapsed x TECHNICAL INFORMATION The OB 100 conforms to ANSI S 1 11 1986 Order 3 Type 2 Sub type C and IEC R225 1966 The normalized passband characteristic of a typical octave filter response is depicted in Figure 24 The OB 100 filter is flat within 0 5 dB in the passband with the 3 dB down points at approximately 707 fc and 1 414 fc where fc is the center frequency of the band chosen The fc 2 and 2fc frequencies are down by approximately 21 dB with the decade points fc 10 and 10fc down by greater than 70 dB The block diagram of the OB 100 illustrated in Figure 25 traces the signal input from the Model 1800 through the filters and back to the sound level meter 35 xe xX I SPECIFICAT 2 IONS a Stand ards j ANSI z S1 11 Z 1986 pA Order S 3 t Type J Bs Sub t oi 015 02 03 04 0608 1 15 2 3 4 6 8 10 ype FREQUENCY RATIO f f and Pees Figure 24 Typical OB 100 Filter Response 1966 Center Frequencies 10 frequencies from 31 5 Hz to 16 kHz Frequency Selection Full manual control or automatic sequential stepping through each frequency Power Source Sound Level Meter Size 3 3 x 2 8 x 1 8 inches 84 x 71 x 47mm Weight 6 ounces 170 grams
31. hone and preamplifier removed the meter can accept other input devices such as the Quest Model VI 90 Vibration Integrator The VA 508C Vibration Assembly combined with the Model 1800 provides a quick and precise method of measuring and analyzing many types of industrial vibration A Assembling the Meter The microphone and preamplifier must be assembled prior to making any measurements Microphone Handling and Storage The microphones used with the model 1800 will provide years of reliable use but certain precautions should be followed with regard to handling and storage Never remove the microphone grid This will expose the diaphragm making it susceptible to physical damage When removing a microphone from the preamplifier be careful not to unscrew only the grid Eh 86 C0 2s Never touch the diaphragm 3 Electret prepolarized microphones should never be stored at high temperatures as long term degradation of the polarization charge may occur This results ina BO BANDASI 140 decrease in microphone sensitivity 4 An electret microphone should be Figure 1 Preamp Assembly stored in its protective box when not in use for long periods of time To attach the microphone to the preamplifier screw the microphone onto the threaded end of the preamp Attach the preamp to the meter by placing the connector ends together and rotating the preamp until it drops onto the meter
32. i gt MED will Z 125 17835 accept up a a a to a 10 Za 5 volt RMS signal L L eee 120 1 00 With the 1k 2k 4k 20k microphone and preamp FREQUENCY Hz removed other transducer devices such as the Quest Model VI 90 Vibration Integrator can be interfaced to give a dB readout on the meter Figure 14 Frequency Amplitude Limitations with Extension Cables Note that when interfacing other input devices to the Model 1800 the 200 volt microphone polarization switch located inside of the battery compartment should be turned OFF for safety Only use pins 1 and 3 for the AC signal input NEVER connect to pins 2 and 4 To remove the preamp keep the preamp housing steady while unscrewing the black plastic collar below the preamp housing Turn in a counter clockwise direction when viewed from the meter top To input an AC voltage electrically requires a special connector Quest part number 14 739 Figure 15 describes the function of each of the pins within the meter input connector 22 F Weighting nas pa 1 SIGNAL INPUT T h e D 2 200V piace ened 3 SIGNAL GND SHIELD stics EA IF 4 417V lt D T USE THIS frequency A G VOLTAGE TO POWER ANY Sais a S CIRCUITRY OTHER THAN c and THE QUEST PREAMP LINear are shown in Figure 15 Meter Electrical Input Direct Figure 16 The man weighting response emulates the res
33. ice organization Should your Quest equipment need to be returned for repair or recalibration please contact the Service Department at 1 800 245 0779 USA or Fax 414 567 4047 for a Return Authorization Number The RA number is valid for 30 days and must be shown on the shipping label and purchase order cover letter If you are unable to return instruments in that time call for a new RA number Send it prepaid and properly packed in the original shipping carton directly to Quest Technologies 510 S Worthington St Oconomowoc WI 53066 U S A Repair or replacement work done under warranty will be performed free of charge and the instrument will be returned to you prepaid Your copy or a photocopy of the Quest Registration Card will serve as proof of warranty should the factory require this information If for any reason you should find it necessary to contact the factory regarding service or shipping damage please direct your calls or letters to the attention of the Service Manager Quest Technologies 414 567 9157 or 800 245 0779 Office hours are from 8 AM to 5 PM Central Standard Time Monday through Friday Warranty Policy Quest Technologies warrants our instruments to be free from defects in materials and workmanship for one year under normal conditions of use and service For U S A customers we will replace or repair our option defective instruments at no charge excluding batteries abuse misuse alterations physical da
34. ill indicate relative battery strength in the bar portion of the display This button may be pressed at any time without affecting the meter signal processing See III A Battery Check for more information RESPONSE Switch The RESPONSE switch controls the rate at which the meter responds to changing input signals Most sound measurements are done with the response set to SLOW The FAST response is generally used when measuring short duration noises such as moving vehicles PEAK is only used in the SPL mode and has no meaning when making integrated measurements The RESPONSE switch positions are as follows SLOW 1 second time constant See Figure 18 FAST 125 millisecond time constant See Figure 19 PEAK 50 microsecond rise time constant with the peak sound level being captured and held until the RESET button is pressed See Figure 20 NOTE Pressing the RESET button while in the PEAK response will not clear out the integration data IMPulse 35 millisecond rise time constant with a decay rate of 2 9 dB sec See Figures 21 and 22 WEIGHTING Switch The WEIGHTING switch controls the frequency response of the meter Weightings A B C or LINear flat may be selected See V E Weighting Characteristics for further detail MODE Switch The MODE switch selects either the sound pressure level or the integrating function to be shown in the digital portion of the display MIN MAX SEL TIME and LEQ will only have val
35. inch microphones are 18pf and 60pf respectively The preamp is removable by turning the black plastic collar below the preamp housing counter clockwise when viewed from the top of the meter 20 6 RELATIVE RESPONSE dB w FREQUENCY Hz Figure 12 Effect of Microphone Output Capacitance on Preamp Low Frequency Response a D 2 Microphone Z Preamp Extension Cables a a T h e a microphone y preamp converts 5 the high z output impedance 10 20 30 40 50 60 70 of the MICROPHONE CAPACITANCE pF microphone to a low Figure 13 Microphone Output Attenuation Caused by Input output Capacitance of Preamp impedance An extension cable of up to 100 feet in length can be connected between the preamp and meter Quest Electronics offers the following lengths of remote cables 59 733 ICM 10 10 Ft Remote Cable 59 734 ICM 50 50 Ft Remote Cable The calibration level at 1kHz and below is affected by less than 0 1 dB with the insertion of a cable Therefore there is no need to recalibrate when the cable is added Maximum output at high frequencies is affected by long cable lengths This effect is shown in Figure 14 21 E Input 140 10 0 Buffer x 2 Ss PN Circuitry 5 Ke ay 2 2S a amp The high 22 135 7 56225 impedance Jo oy oY So ti input wh Sy a x Fg aw m g E circuitry OW 130 65s 1 Megohm WZ 3 1 mA in series at 39 with 0 1 2a
36. ing r n conditions Figure 8 Chart Recording of SPL must be observed L Set the RESPONSE switch on the meter to FAST The NL 15 will convert FAST to SLOW as required 2 Set the dB RANGE switch to either 80 140 dB or 60 120 dB If used on other ranges all data will be in error by either 20 dB or 40 dB 3 Set the WEIGHTING switch on the meter to either A or C If other weightings are used the weighting data on the printout will be in error The rest of the readings will be correct In addition the internal switches in the NL 15 must be set to agree with the sound level meter settings ds If the meter is to be used on the 80 140 dB range set NL 15 internal switch 1 position 4 to OFF If the meter is to be used on the 60 120 dB range set NL 15 internal switch 1 position 4 to ON oar If the meter is set to A weighting set NL 15 internal Switch 1 position 3 to OFF If the meter is set to C weighting set NL 15 internal switch 1 position 3 to ON 16 The remainder of the internal switch settings are set the same as they would be for a Micro 15 Consult the NL 15 manual for complete instructions The NL 15 will accumulate data when it is connected to the meter DATA OUTPUT jack if the following two conditions are met Le The LED on the NL 15 is blinking 2 The RUN annunciator on the meter display is on To operate dg Connect the two units Note An adapter cable from Quest is needed to adapt the
37. l RUN MODE period When used with the filter set OFF this information includes Meter WEIGHTING and RESPONSE settings LEQ MAX MIN and SEL Levels RUN TIME and OL TIME Table of EXCEEDANCE LEVELS dB AWH EXCEEDANCE LEVELS Tabulated from 1 to 99 the SPL level that was exceeded for x percentage of time See Figure 5 Sample Printout If an OB 100 or OB 300 is used as part of the sound measuring system all of the information above the OCTAVE FILTER SET header will pertain only to the last Octave Band measurement This allows the user to perform for example a 500 Hz Octave Band Measurement on A Weighting SLOW Response and obtain a printout that includes proper switch settings and exceedance levels for that frequency NOTE For forty column printers the Sound Level Meter allows for a compressed print mode Pressing the HOLD button before printing causes the meter to send a printer control code LPRINT CHR 15 that produces a compressed print form for many printers Consult your printer manual for details 10 QUEST MODEL 1800 PRECISION INTEGRATING SOUND LEVEL METER DATE SERIAL NO CALIBRATED LINEAR WEIGHTING SLOW RESPONSE LEQ dB MAX dB MIN dB SEL dB RUN TIME OL TIME 101 9 107 2 86 9 117 5 00 37 EXCEEDANCE LEVELS dB 0 1 2 3 4 5 6 7 8 9 LOO 107 107 107 107 107 107 107 107 107 107 L10 107 107 107 107 107 107 107 107 107 107 L20 107 107 107 107 107 107 107 107 107 106 L30 106 106 106
38. mage or instruments previously repaired by other than Quest Technologies Microphones sensors printers and chart recorders may have shorter warranty periods This warranty states our total obligation in place of any other warranties expressed or implied Our warranty does not include any liability or obligation directly resulting from any defective instrument or product or any associated damages injuries or property loss including loss of use or measurement data For warranty outside the U S A a minimum of one year warranty applies to the same limitation and exceptions as above with service provided or arranged through the authorized Quest sales agent or our Quest European Service Laboratory Foreign purchasers should contact the local Quest sales agent for details 48
39. ms Active filters are employed throughout the Model OB 300 thus permitting the unit to have both high accuracy and compact size XIII ABOUT THE FILTER A Filter Controls POWER Switch A three position slide switch that does the following OFF Disconnects the filter circuitry from the attached sound level meter With this switch in the off position the OB 300 does not use any power from the meter batteries MANUAL Filter frequency selection is performed with two push buttons START Buttons AUTO Unit automatically cycles through the desired filter frequencies storing sample information for each frequency during the RUN mode START Buttons Allow the user to cycle through the different bandpass filters The two buttons allow manual frequency control in the MANUAL Mode or frequency directional control in the AUTO Mode 20 dB Button When this button is depressed the output of the filter is amplified by exactly 10 times 20 dB and then fed back to the sound level meter Therefore 20 dB has to be subtracted from the meter reading when using this button 38 MODE Switch Selects either the 1 3 octave filter set 33 frequencies or the 1 1 octave filter set 11 frequencies TIME A screwdriver adjustment to control the automatic cycle time of each filter frequency from approximately 5 to 30 seconds B Filter Connector The 30 pin connector on the top of the filter is used for connecting the
40. nd LEQ that occurred can be viewed Simply use the MODE switch to select the value of interest Pressing HOLD will NOT stop an LEQ measurement accumulation It simply saves the current value for viewing HOLD is a toggle function Therefore to exit the HOLD mode simply press HOLD again RESET Button To reset ALL data stored within the Model 1800 press the RESET button This will erase all stored data prior to taking new readings NOTE Pressing RESET while the RESPONSE is set to PEAK only resets PEAK All other data remains unaffected RUN Button The RUN indicator will appear in the display when the RUN button is pressed The meter will begin integration at this point MAX MIN SEL TIME and LEQ data is collected only during the RUN mode Pressing the RUN button again will exit the RUN mode and the instrument will enter the PAUSE mode where MAX MIN SEL TIME and LEQ are held at their last values Press the RUN button again to continue updating MAX MIN SEL TIME and LEQ Press RESET to erase all existing data before taking new data PRINT Button If the Model 1800 is connected to a printer via the PRINT output jack pressing the PRINT button will send all of the current data stored in the meter to the printer During the printout period the numeric display will read Prn To stop the printout just press the print button again See Figure 5 Sample Printout BATTERY Button Pressing the BATTERY button w
41. otentiometer located through the small hole on the left side of the meter until the display matches the calibration level NOTE Most Calibrators including Quest Calibrators are affected by changes in altitude and barometric pressure The rated SPL is set at standard barometric pressure at sea level 760 mm Hg Consult the Calibrator Manual for correction factors at different altitudes and how to apply them LL Iv GENERAL OPERATING CONSIDERATIONS Before taking measurements with the Model 1800 there is a series of quick checks and considerations that should be performed or noted After switching the unit ON the batteries should be checked and replaced if needed Although the Model 1800 will maintain accurate calibration over a long period of time the calibration should be checked and the meter slightly adjusted if necessary before each use Set the RESPONSE WEIGHTING MODE and dB RANGE switches as needed Hold set or tripod mount the meter in the desired location If performing integrating measurements press the RUN button making sure RUN is indicated in the display If the meter is in the RUN mode and you want to change a switch setting particularly the dB RANGE switch it is a good idea to stop accumulating data by entering the pause mode To do this depress the RUN button again and RUN will disappear from the display Change the desired switches and then depress RUN again to continue accumulating data It i
42. ponse of the human ear and is used for most industrial and community noise measurements B weighting is seldom used C weighting is often used for measuring noise reduction in hearing protectors and for other scientific purposes The LINear weighting has a flat frequency response over the range of human hearing and is useful in many applications such as audiometric analysis It is also used when taking octave and 1 3 octave measurements LINEAR RELATIVE RESPONSE lt dB 79 V4 reer 1 init poi 1 sami rarer L a poi 1 3 5 10 20 50 100 200 500 lk ek Sk 10k 20k 30k FREQUENCY Hz gt Figure 16 Weighting Characteristics 23 G Internal Electrical Noise The maximum measurable SPL of the 1800 Meter is 140 dB with a sinusoidal input 120 dB if measuring a complex signal with a 20 dB crest factor With optional microphones the upper range can be extended to 150 dB When used with either the OB 100 or OB 300 filter octave mode the specific minimum measurable SPL s when using either the Model QE4170 or the Model QE4146 microphone are as shown in Figure 17 The inherent noise level is typically at least 5 dB below the RMS values shown in each table Model QE4170 1 Inch Microphone Octave Weighting Scale All Pass 31 5 and 63 125 and 250 500 and 1K 2K and 4K 8K and 16K Model QE4146 One Half Inch Microphone Octave Band All Pass 31 5
43. ration as follows L Read the calibrator 1 kHz output level Set the meter dB RANGE switch so that the calibrator level will indicate within the upper 20 dB of the meter display Set the RESPONSE switch to FAST WEIGHTING switch to LIN and MODE switch to SPL Turn the POWER switch to ON 2 Set the OB 300 POWER switch to MANUAL and the MODE switch to 1 1 Press the RUN button to place the meter into the RUN mode Then use the two direction buttons to select the 1 kHz filter J Place the calibrator and adapter if needed onto the microphone Turn the calibrator ON A meter reading that is very close to the level listed on the calibrator should result An error of 0 5 dB is acceptable This is due to the center frequency filter tolerance of 0 5 dB maximum 4 Change the OB 300 filter frequency first to 500 and read the display Then change to 2k and read the display At both frequencies the readings should be 19 to 23 dB less than the 1 kHz calibrator level By Change the OB 300 filter frequency to 1k and the meter dB RANGE so that the meter reads 20 to 40 dB less than full scale Press and hold the 20 dB button on the OB 100 The meter reading shall rise approximately 20 dB to verify that the 20 dB button functions 6 Remove the calibrator The analyzer is now ready to use B Taking a Measurement 1 Turn the meter POWER switch ON The meter will come on in the Pause mode Perform a BATTERY test to verify
44. s always a good idea to document all measurement conditions and meter settings for possible future needs If a printer is used the settings will all appear on the printout A Meter Microphone Placement Whenever possible the meter should be tripod mounted in a relatively open area to minimize reflections from the body or other large reflective structures Avoid placement against a wall or in a corner If body reflections are of concern a microphone extension cable may be used for better microphone placement When taking measurements while holding the meter in your hand keep your arm fully extended When using a random incidence or pressure microphone point it approximately 70 degrees to the direction of the sound If using a free field microphone point it directly at the noise source 0 degrees B Background Noise Background noise can cause considerable error in measurement when its intensity is close to that of a particular noise source of interest When it is not possible to eliminate or reduce the background noise use the curve shown in Figure 6 to correct for the effect of the background noise on the 12 measuremen t ERROR IN dB SUBTRACT FROM TOTAL NOISE w 0 0 1 2 3 4 5 6 7 8 9 DIFFERENCE BETWEEN TOTAL READING AND BACKGROUND NOISE dB Figure 6 Effect of Background on Measurement 13 C Wind Screen Effects To prevent erroneous me
45. sent When the instrument is done sending the information the PC will respond with 1 FILE COPIED There now exists a file called filename in the current directory in the computer The user can print this out by typing PRINT filename lt enter gt 46 B Downloading Using Windows There is a variety of commercially available software that can easily accept data from the meter These software packages are usually termed communications software Microsoft Windows has a communications program under the Accessories icon called TERMINAL Instructions on how to use it are located in the Windows manuals Using any of these communications programs the user must select the com serial port and the baud rate The Quest cable must be plugged into the selected com port and the baud rate on the unit must match the rate selected in the software The PC programs also need the following information in their setup data bits 8 stop bits 2 parity none handshaking flow control hardware For TERMINAL the settings are found by first selecting SETTINGS then COMMUNICATIONS 47 QUEST SERVICE AND WARRANTY POLICY Service Policy The Quest product you have purchased is one of the finest acoustic instruments available It is backed by our full one year warranty which seeks complete customer satisfaction This is your assurance that you can expect prompt courteous service for your equipment from the entire Quest serv
46. that the analyzer has sufficient battery power Replace the batteries if the bar indicator falls below the indicating arrow located at 5 on the 0 60 scale 2 Set the dB RANGE switch to 80 140 dB Set the RESPONSE switch to FAST WEIGHTING switch to LIN see note and the MODE switch to SPL 40 NOTE Note that the filter response can be in series with either A B C or LIN This is the operator s choice However LIN is generally used when taking octave band measurements 3x Turn the OB 300 POWER switch to MANUAL to activate the filter will appear in the display with the meter in the Pause mode Select either 1 3 or 1 1 filters using the MODE switch 4 Select the desired WEIGHTING and RESPONSE Then change the dB RANGE switch down in 20 dB steps until the OL indicator flashes or stays on Then go back up 20 dB so that the OL indicator stays off This ensures that the AC input to the filter is at its maximum voltage without clipping overloading MANUAL Filter Operation Place the meter into the Pause mode using the RUN Pause button Press RESET to clear all internal memory Select the first frequency of interest Then enter the RUN mode for the required amount of time necessary to obtain a valid sample Then enter the Pause mode change to the next frequency of interest and enter RUN again etc Repeat this process for all frequencies of interest Note that it is not necessary to enter the pause mode between e
47. tic cycle time of each filter frequency from approximately 5 to 30 seconds 31 B Filter Connector The 30 pin connector on the top of the filter is used for connecting the filter to the sound level meter Figure 23 shows the pinout for the filter connector IX GENERAL OPERATING 16 0 1 D PROCEDURE AS VIEWED INTO 45 p al gt cam CND the Mode PILTER CONNECTOR jg G 3 SIG IN FROM METER OUTPUT 1800 100 laa aa Octave FREQUENCY CODE B and 2 00 6 c TO METER Analyzer e2 0 0 7 D is made up 23 00 8 E of the 24 00 9 F Model 1800 25 o 0 10 BLANK DUT TO METER Precision 26 OG 11 SIG OUT TO METER mpulse 27 0 0 12 LD OUT TO METER ae 28 0 0 13 65 V FROM METER g p S 29 0 0 14 65 V FROM METER F 30 0 0 15 ON OFF TO METER Meter and the OB 100 Octave Filter Figure 23 OB 100 External Filter Connector Set The Located on Meter Bottom two units a i e connected together with the long captive screw provided with the filter box The General Operating Considerations for the Model 1800 Section IV are asically the same when using the Model OB 100 with the meter b A Operational Check he Model 1800 should be calibrated as outlined in the meter section of the anual Section III B Calibration while the OB 100 is OFF The OB 100 has fixed input to output voltage ratio of approximately 1 0 dB at each
48. ues if the meter has been in the RUN mode accumulating data SPL Sound Pressure Level will be displayed SPL is also always shown in the display bar indicator MAX The Maximum Sound Pressure Level obtained while in the RUN mode is shown in the numeric display MIN The Minimum Sound Pressure Level obtained while in the RUN mode is shown in the numeric display SEL The Sound Exposure Level of accumulated sound averaged over one second while in the RUN mode is shown in the numeric display TIME The total RUN time will be displayed The format is MIN SEC for any time less than 20 minutes and HRS MIN for any time greater than 20 minutes LEQ The average integrated sound level accumulated while in the RUN mode is shown in the numeric display dB RANGE Switch The displayed range of the Model 1800 is 60 dB and is switchable between the following 20 80 dB 40 100 dB 60 120 dB or 80 140 dB POWER Switch When turned ON the meter begins with all data reset to zero and is in the pause mode non RUN mode By switching the unit OFF all accumulated data is cleared from the memory C Overload Detection In the SPL mode the overload indicator OL is displayed whenever the incoming signal saturates overloads the circuitry It appears as OL in the upper right hand corner of the display If the OL indicator is on increase the dB RANGE switch until the OL condition is removed causing OL to disappear The Model 1
49. y be used as a Precision Sound Level Meter Integrating Sound Level Meter In all modes accuracy for noise measurements and statistical analysis 29 29 29 29 29 29 30 30 30 31 32 32 33 33 34 36 36 36 36 36 36 37 37 37 37 38 38 39 39 40 40 41 43 44 44 45 46 46 46 Impulse or the Model 1800 delivers Type 1 Applications include laboratory industrial community and audiometric measurement and analysis The Model 1800 is a user friendly hand held meter with an LCD display that provides a numerical and bar graph readout It is housed in a tough injection molded plastic case with internal shielding The meter is configured and operated with easy to use slide switches and push buttons Two output jacks are provided for connecting to external peripherals such as chart recorders or serial data printers Plug in the Model OB 300 combination 1 3 1 1 Octave Filter Set and create a precision 1 3 or 1 1 octave band analyzer covering 33 bands from 12 5 Hz to 20 kHz The addition of the Model OB 100 Octave Filter Set will create a precision octave band analyzer covering 10 bands from 31 5 Hz to 16 kHz If sound measurements need to be made from a distance simply remove the microphone pre amplifier and insert either an ICM 10 10 foot or an ICM 50 50 foot extension cable Distances of up to 100 feet can be accommodated by adding two ICM 50 50 foot extension cables in series With the microp
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