Digital Sound Level Meter

33-2055User’s Guide

Thank you for purchasing your Digital Sound Level Meter from RadioShack. Please read this user’s guide before installing, setting up, and using your new meter.

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Setup Package contents • DigitalSoundLevelMeter • CarryCase

• User’sGuide • QuickStart

Features• Forhome/hobbyistuse:finetuneyourstereo,PAsystem,orhometheater

• Attachestoatripodwith¼inchconnector

• Selectableweightingfornoiselevelormusicalsound

• Displaysaverageormaximumsoundlevel

• Integratedaveragingfrom1to199seconds

1 Install batteryYourmeterrequiresone9Vbattery(notincluded)forpower.WhenBATTdisplaysorthemeterstopsoperatingproperly,replacethebattery.

1. SetRANGEtoOFF.

2. Removethebatterycompartmentcoverbypressingbothsideinandliftingthecover.

3. Installone9Vbattery(notincluded)asindicatedbythepolaritysymbols(+and–).

b Battery Notes:• After using the meter, set RANGE to OFF to save power.• Disposeofbatteriespromptlyandproperly.Donotburn

or bury them.• Useonlyfreshbatteriesoftherequiredsizeandtype.

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Tripod Adapter

OUTPUT Jack

Microphone

RANGE Switch

WEIGHTING / RESPONSE

DH / RESET / MIN / MAX

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• Ifyoudonotplantouseyourmeterforalongperiod,remove the battery. Batteries can leak chemicals that may damage electronic parts.

2 Mount and connect the meter (Optional)1.Mountthemeterona(¼–inch)tripodtoeliminatehandnoiseandminimizetheeffectsofsoundreflectedfromyourbody.Thismakesiteasytousethemeterwithauxiliaryrecordingortestequipment.

2. Useanaudiopatchcord(notincluded)toconnecttheOUTPUT Jacktoyourstereosystemortestequipment.

3 Set the sound rangeSetRANGE tothedesiredsoundrange.Ifyoucannotgetareading,tryotherrangesuntilyougetareading,referto“Continuous Average Measurements”onPage7.

4 Set the weightingPressWEIGHTINGtoselectAtodeterminethenoiselevelofanarea,orCtomeasuresoundlevelsofmusicalmaterial.Referto“Setting the Weighting”onPage5.

5 Set the response timePressRESPONSEtosettheresponsetoFASTorSLOW.Referto“Setting the Response Time”onPage5.

6 Read the measurementPointthemicrophoneatthesoundsource.Themeterdisplaysthecontinuousaveragesoundlevel.Afterthemeasurement,setRANGEtoOFF.

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Setting the Meter

Setting the WeightingPressWEIGHTINGtoselectAorC.

Weightingdeterminesthemeter’sfrequencyresponsecurve.

A-weightinghasA-curvefrequencycharacteristicsandcausesthemetertorespondmainlytofrequenciesrangingfrom500to10,000Hz.Thisisthehumanear’smostsensitiverange.SelectAtodeterminethenoiselevelofanarea.

C-weightinghasC-curve(flat)frequencycharacteristicsandcausesthemetertorespondmainlytofrequenciesrangingfrom32to10,000Hz.SelectCtomeasuresoundlevelsofmusicalmaterial.

n Note: You can change the weighting setting only during a continuous average or maximum measurement.

Setting the Response TimePressRESPONSEtoselectFASTorSLOW.

WhensettoFAST,themeterupdatesthebargraphevery0.2seconds.WhensettoSLOW,themeterupdatesthebargraphevery0.5seconds.

n Note: You can change the response setting only during a continuous average or maximum measurement.

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Understanding Indications

Level IndicatorThemeterdisplayssoundlevelusinganumberandabargraph.ThenumbershowsthesoundlevelindBwithin±10dBoftheselectedrangeandisupdatedonceasecond.

Thebargraph’scenterpointrepresentsthemidpointoftheselectedrange,forexample,forRange70,thecenterpointrepresents70dB.Thebargraphupdatesevery0.2secondsor0.5seconds.

Overrange IndicatorWhenthesoundlevelishigherthanthehighestnumberintheselectedrange,thebargraphgoesto+10dBandboththebargraphandthenumberthatrepresentsthenextrangeflash.

Forexample,ifthemetermeasures91dBinRange80,thenthenumber90andthebargraphflash.Ifthemetermeasuresmorethan126dBinRange120,thenumber126andthebargraphflash.

Ifyougettheoverrangeindicator,tryahigherrangesettinguntilyougetareadingintheupperhalfoftherange(0to+10dB).

Underrange IndicatorWhenthemeasuredsoundlevelislowerthanthelowestsoundleveloftheselectedrange,LOappears

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andthebargraphdisappears.Ifthishappens,trythenextlowerrange.

n Notes:• Theoverrangeorunderrangeindicatorcanalsoappear

when you recall a reading using the measurement holding function and the measurement is under or over the selected range.

• The meter can measure sound levels only from 50 to 126 dB.

Taking Measurements

Continuous Average MeasurementsFollowthesestepstomeasuretheaveragesoundlevel.

1. SetRANGEtothedesiredrangesetting.Ifthesoundlevelisveryhigh,startatthehighestrangesetting(120)andreducethesettinguntilyougetareading.

Therearesevenranges.Eachcovers20dB.Thenumberofarangerepresentsthecenteroftherange.Whenthemeasuredvalueislowerorhigherthanthesetrange,anunderrangeoroverrangeindicatorappears.See“Underrange Indicator”and“Overrange Indicator”onPage6.Takemeasurementsatseveraldifferentpointsintheareatogetagoodaverage.

n Notes:• IfyousetRANGE to 120, the meter measures sound

levels from 110 to 126 dB.• Ifyouchangetherangesettingduringa

measurement, you clear all the current data and a continuous average measurement resumes.

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2. Settheweightingandresponse(see“Setting the Weighting”and“Setting the Response Time”onPage5).

3. Pointthemeter’smicrophoneatthesoundsource.Themeterdisplaysthecontinuousaveragesoundlevelduringaone-secondsamplingperiodandupdatesthenumberonthedisplayonceasecond.

4. Afterthemeasurement,setRANGEtoOFF.

Taking Maximum Measurements1. FollowSteps1-3in“Continuous Average Measurements”.

2. PressMAX;thewordMAX appears.

Themeterdisplaysonlytheloudestmeasuredsoundlevelduringtheone-secondsamplingperiod.Thebargraphshowsthemaximumlevelevery0.2or0.5seconds.

Thebargraphsegmentthatcorrespondstothepeakreadingstaysonthedisplayfor2secondsoruntilthemetermeasuresahighermaximumlevel.

3. PressMAXagaintocancelthecontinuousmaximummeasurement.Acontinuousaveragemeasurementresumes.

Integrated Average MeasurementsFollowthesestepstomonitorthesoundlevelandaveragethemeasurementoveraperiodof1to199seconds.Themeterstorestheaverage,maximum,andminimumsoundlevelsduringthesettime.

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1. PressandholdDHforabout2secondsduringacontinuousaverageormaximummeasurement.Thedigit1appears.

2. Press(orpressandhold)MAXorMINtosetaperiodfrom1to199seconds;positionthemeterforthemeasurement.

3. PressRESETtostartthemonitoring.

Themeterupdatesthecurrentintegratedaveragedisplayonceasecond.MINandMAXflashuntilthesettimeisup.Whenthesettimeisup,DHappears,andMINandMAXgoonflashing.Themeterdisplaysthetotalintegratedaveragesoundlevel.

4. PressMAXtodisplaythemaximumsoundlevelforthesettime,pressagaintoreturntothetotalintegratedaveragesoundlevel.

PressMINtodisplaytheminimumsoundlevelforthesettime,pressagaintoreturntothetotalintegratedaveragesoundlevel.

5. PressRESETafteryouchecktheaverage,maximum,andminimumsoundlevels.Acontinuousaverageormaximummeasurementresumes.

n Notes: • IfyouchangetheRANGE setting during an integrated

average measurement, you clear any stored data and a continuous average or maximum measurement resumes.

• Youmustrepeattheprocedurefortakinganintegratedaverage measurement.

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Taking Maximum and Minimum Measurements during an Undetermined Time Period1. PressRESETduringacontinuousaverageormaximummeasurement.Attheendofthedesiredtimeperiod,pressDH.DHdisplays.

2. PressMAXandMINrespectivelytochecktheaverage,maximum(MAXstopsflashing),andminimum(MINstopsflashing)soundlevelsduringthetimeperiod.

3. PressRESETtoresumeacontinuousaverageormaximummeasurement.

Checking Stereo System AcousticsTocheckthesoundofastereosystem,useanaudiosamplethatproducespuretones,oneatatime,atintervalsthatspantheentireaudiospectrum.UseC-weightingwitheithersloworfastresponse.

Makeagraphortabletoshowthesoundleveleachtoneproduces.Thisgivesyouaclearideaofthefrequencyresponseofthetotalaudiosystem,includingtheroom.Tosmoothouttheresponse,adjustthetonecontrol,changespeakerplacements,anduseafrequencyequalizer.

Holding MeasurementsYoucanstorethecurrentmeasurementsinmemoryandfreezemeasurementsonthedisplay.Themeterstorestheaverage,maximum,andminimumsoundlevelsforthelastonesecond.

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1. PressDHduringacontinuousaverageormaximummeasurement.DHdisplaysandthelastaverageormaximummeasurementisfrozen.

2. Foranaveragemeasurement,whatisfrozenisthelastaveragereading.PressMAXtocheckthelastmaximummeasurement.MAXdisplays.PressMAXagaintoreturntotheaveragemeasurement.

Foramaximummeasurement,whatisfrozenisthelastmaximumreading.

3. PressMINtocheckthelastminimummeasurement.MINdisplays.PressMINagaintoreturntotheaverageormaximummeasurement.

4. PressRESETtoreturntothecontinuousaverageormaximummeasurement.

n Note: When you set RANGE to a different range during measurement holding, you disable the holding function and return to a continuous measurement.

Care and Service• Keepyourmeterdryandclean.Ifitgetswetordirty,wipeitdryorcleanimmediately.Donotuseharshchemicals,cleaningsolvents,orstrongdetergentstocleanthemeter.

• Useandstorethemeterinnormaltemperatureenvironmentsonly.Temperatureextremescanshortenthelifeofelectronicdevicesanddistortormeltplasticparts.

• Handlethemetergentlyandcarefully.Droppingitcandamagethecircuitboardsandcausethemetertoworkimproperly.

• Modifyingortamperingthemeter’sinternalcomponentscancausemalfunctionandmightinvalidateitswarranty.Ifyourmeterisnotperformingasitshould,takeittoyourlocalRadioShackstoreforassistance.

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SpecificationsBattery.................................................................................. 9VAlkaline

Microphone............................................................ ElectretCondenser

Range..................................................................................50to126dB

Accuracy............................................................... ±2dBat114dBSPL

Reference........................................................ 0dB=0.0002MicroBar

Weighting.................................................................................. AandC

DisplayResponse........................................................... FastandSlow

Signal Output:

Voltage................................................................ 1VoltPeak-PeakMin.(OpenCircuit,FullScaleat1kHz)

Impedance.............................................................10KohmMin.Load

Distortion..............................Lessthan2%at1kHz,0.5Vp-pOutput(Input:MicOut,Output:10Kohm)

OperatingTemperature.................................32to122°F(0to50°C)

StorageTemperature................................ -40to149°F(-40to65°C)

Dimensions(HWD)....................6¼×2½×1¾inch(159×64×44mm)

Weight(includingbattery)...............................................6.7oz(190g)

Specificationsaresubjecttochangeandimprovementwithoutnotice.Actualproductmayvaryfromtheimagesfoundinthisdocument.

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Limited WarrantyRadioShackwarrantsthisproductagainstdefectsinmaterialsandworkmanshipundernormalusebytheoriginalpurchaserforninety (90) days afterthedateofpurchasefromaRadioShack-ownedstoreoranauthorizedRadioShackfranchiseeordealer.RADIOSHACKMAKESNOOTHEREXPRESSWARRANTIES.

Thiswarrantydoesnotcover:(a)damageorfailurecausedbyorattributabletoabuse,misuse,failuretofollowinstructions,improperinstallationormaintenance,alteration,accident,ActsofGod(suchasfloodsorlightning),orexcessvoltageorcurrent;(b)improperorincorrectlyperformedrepairsbypersonswhoarenotaRadioShackAuthorizedServiceFacility;(c)consumablessuchasfusesorbatteries;(d)ordinarywearandtearorcosmeticdamage;(e)transportation,shippingorinsurancecosts;(f)costsofproductremoval,installation,set-upservice,adjustmentorreinstallation;and(g)claimsbypersonsotherthantheoriginalpurchaser.

Shouldaproblemoccurthatiscoveredbythiswarranty,taketheproductandtheRadioShack salesreceiptasproofofpurchasedatetoanyRadioShack storeintheU.S.RadioShack will,atitsoption,unlessotherwiseprovidedbylaw:(a)repairtheproductwithoutchargeforpartsandlabor;(b)replacetheproductwiththesameoracomparableproduct;or(c)refundthepurchaseprice.Allreplacedpartsandproducts,andproductsonwhicharefundismade,becomethepropertyofRadioShack.Neworreconditionedpartsandproductsmaybeusedintheperformanceofwarrantyservice.Repairedorreplacedpartsandproductsarewarrantedfortheremainderoftheoriginalwarrantyperiod.Youwillbechargedforrepairorreplacementoftheproductmadeaftertheexpirationofthewarrantyperiod.

RADIOSHACKEXPRESSLYDISCLAIMSALLWARRANTIESANDCONDITIONSNOTSTATEDINTHISLIMITEDWARRANTY.ANYIMPLIEDWARRANTIESTHATMAYBEIMPOSEDBYLAW,INCLUDINGTHEIMPLIEDWARRANTYOFMERCHANTABILITYAND,IFAPPLICABLE,THEIMPLIEDWARRANTYOFFITNESSFORAPARTICULARPURPOSE,SHALLEXPIREONTHEEXPIRATIONOFTHESTATEDWARRANTYPERIOD.

EXCEPTASDESCRIBEDABOVE,RADIOSHACK SHALLHAVENOLIABILITYORRESPONSIBILITYTOTHEPURCHASEROFTHE

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01A1133-2055

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