Extech Instruments 407703A User manual

User’s Manual
Model 407703A
Analog Sound Level Meter
Introduction
Congratulations on your selection of the Extech Analog Sound Level Meter, a versatile device that
measures sound pressure level in any acoustic environment. Sound/Noise Levels that are high or
low volume, high or low-pitched, broadband, intermittent, or continuous can easily be measured in
factories, schools, offices, airports, sound studios, theaters, auditoriums, automobiles, and in the
home. This precisely calibrated meter features a large, easy-to-read analog indicator and is battery
powered for portable use.
Specifications
Ranges 54 to 126dB in 7 ranges (referenced to 0.00002 bar)
Resolution Analog Continuous
Accuracy ±2 dB at 94 dB sound level
Microphone type Condenser Electret
Analog output AC: 0.707Vrms (full scale)
Meter power 9V battery (120-hour battery life)
Dimensions/Weight 2.7 x 7.1 x 1.4" (68 x 180 x 36mm) / 5.1 oz. (160g)
Front Panel Description
1 Microphone
2 Range switch
3 MAX HOLD button
4 SLOW/FAST switch
5 A/C weighting switch
6 Analog display
7 Battery compartment
8 AC analog output jack

407703A-EN v1.9 07/13
Operation
Weighting A / C
Slide the Weighting switch to select A or C weighting Use ‘A’ weighting to have the meter respond
as the human ear would with regard to frequency response (the human ear boosts and cuts
amplitude over the frequency spectrum therefore it is not ‘flat’ responding). ‘A’ weighting is used for
environmental measurements, OSHA regulatory testing, law enforcement, and workplace design.
Select ‘C’ weighting for a flat response (especially at lower frequencies). ‘C’ weighting is suitable
for the sound level analysis of machines, engines, etc.
Fast (F) and Slow (S) Response
Slide the Fast or Slow switch to select the response. Selection of Fast or Slow is determined by the
application and any directives or standards related to that application. For example, most hearing
conservation or OSHA related testing is done using SLOW and A weighting.
Setting the Range
Start with the highest range setting (120 dB) and work downward in range using the Rotary Switch
until there is significant deflection of the meter's pointing needle. For greatest accuracy, always use
the lower of any two possible settings. For example: If the RANGE is set to 80 dB and meter reads
approx. -5, reset the RANGE to 70 dB and the meter will read +3, for actual sound level of 73 dB.
Max Hold
Maximum Hold permits the user to freeze the maximum reading by locking the needle indicator at
the sound level peak. Press and hold the MAX button to use Max Hold.
Low Battery Indication
Place the Rotary Select switch to the 'BAT' position and observe the analog pointer for status of the
battery voltage. Replace the battery when the pointer indicates a weak battery. Remove power to
the meter whenever it is not being used to preserve battery life.
Analog Output
A phono jack is provided on the meter for connection to external test equipment. An AC rms voltage
is provided (0.707V maximum) which is a linearized representation of the analog pointer reading.
Connect this output to a datalogger, chart recorder, etc. for logging purposes.
Tripod Mount
A threaded insert on the rear of the meter permits attachment to a tripod stand for increased stability
and accuracy (eliminates hand noise and minimizes the effects of sound reflected from the user's
body).
Battery replacement
Remove the battery compartment cover on the rear of the meter by removing the cover screw.
Replace 9V battery and compartment cover.

407703A-EN v1.9 07/13
Warranty
FLIRSystems,Inc.warrantsthisExtechInstrumentsbranddevicetobefreeofdefectsinpartsandworkmanshipforoneyear
fromdateofshipment(asixmonthlimitedwarrantyappliestosensorsandcables).Ifitshouldbecomenecessarytoreturnthe
instrumentforserviceduringorbeyondthewarrantyperiod,contacttheCustomerServiceDepartmentforauthorization.Visit
thewebsitewww.extech.comforcontactinformation.AReturnAuthorization(RA)numbermustbeissuedbeforeanyproductis
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Thiswarrantydoesnotapplytodefectsresultingfromactionoftheusersuchasmisuse,improperwiring,operationoutsideof
specification,impropermaintenanceorrepair,orunauthorizedmodification.FLIRSystems,Inc.specificallydisclaimsanyimplied
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consequentialdamages.FLIR’stotalliabilityislimitedtorepairorreplacementoftheproduct.Thewarrantysetforthaboveis
inclusiveandnootherwarranty,whetherwrittenororal,isexpressedorimplied.
Calibration,Repair,andCustomerCareServices
FLIRSystems,Inc.offersrepairandcalibrationservicesfortheExtechInstrumentsproductswe
sell.NISTcertificationformostproductsisalsoprovided.CalltheCustomerServiceDepartmentfor
informationoncalibrationservicesavailableforthisproduct.Annualcalibrationsshouldbe
performedtoverifymeterperformanceandaccuracy.Technicalsupportandgeneralcustomer
serviceisalsoprovided,refertothecontactinformationprovidedbelow.
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