42AB

Fittedwitharemovableadapterforcalibrating1⁄2-inchmicrophones.Removethisforcalibrating1-inchmicrophonesG.R.A.S.Sound&VibrationStaktoften22D2950Vedbæk,DenmarkTel+4545664046Fax[phone]e-mail:[e-mail]cationsTheG.R.A.S.SoundCalibratorType42AB(Fig.1)isasmallbattery-operatedprecisionmicrophonecalibrator.Thecalibratorcanbeuseddirectlyon1-inchand1⁄2-inchmicrophones.For1⁄4-inchmicro-phones,usetheincludedadapter.Anadapterforcal-ibrating1⁄8-inchmicrophonesisavailable.TheType42ABworksatthereferencefrequency(1kHz)oftheinternationallystandardizedweight-ingltersA,B,CandD.Thismeansthatitcanbeuseddirectlyforcalibratingsoundlevelmetersandothersimilarequipmentwiththeseweightingltersactivatedwithouthavingtomakecorrections.Thecalibrationlevelis114dB(re.20µPa)whichcorre-spondswith10Pa.Thisisenoughtoensureimmu-nitytobackgroundnoisewithoutoverloadingtheequipment.TheType42ABconsistsofasoundsource,aref-erencemicrophoneandanelectroniccontrolcir-cuit.Thespecialreferencemicrophoneisextremelystableandindependentofvariationsinbarometricpressure,temperatureandhumidity.Thereferencemicrophoneandcontrolcircuit,together,maintainaconstantsoundpressurelevelinsidethecalibrationchamberandautomaticallyadjustsforchangesinloadvolume,temperature,humidityandbarometricpressure.Furthermore,thecalibratorwillautomati-callyswitchoffwhenthemicrophoneundertestisremovedfromthecalibrationchamber.TheoutputleveloftheType42AB,viz.114dB(re.20µPa)at1kHz,meetstherequirementsofIECStandard60942Class1andisthereforeinaccord-ancewithinternationalstandards.TheType42ABissuppliedwithaleatherprotectioncaseandanindividualcalibrationcerticate.Typicalapplications■Microphonecalibration■MicrophonecomparisonsSoundCalibratorType42ABFig.1SoundCalibratorType42ABVers.08-07-02G.R.A.S.Sound&VibrationStaktoften22D2950Vedbæk,DenmarkTel+4545664046Fax[phone]e-mail:[e-mail]cationsandaccessorieswithoutnoticeSoundCalibratorType42ABAmbientrequirementsforspeciedoperation:Temperature:............–10°Cto+50°CAmbientpressure:........65kPato108kPaHumidity:................10%to90%RHBattery:Type:........................6LR61,9VLife:........................≈30hoursBatterytype6F22Ghasashorterlife,whereasa9Vlithiumbatterygivesanextendedoperatingtime.Externalsupplyvoltage:7.5Vto15VAutomaticshut-offwhenvoltagedropsbelow7.5VOverallweightanddimensions:Weight:................185gmwithbatteryLength:........................109.5mmDiameter:........................40mmAccessoriesincluded:Deliveredttedwitharemovableadapterforcalibrating1⁄2-inchmicrophones.Removethisforcalibrating1-inchmicrophones.Adapterfor1⁄4-inchmicrophones:....RA00499Valkalinebattery:................EL0003Accessoriesavailable:Adapterfor1⁄8-inchmicrophones:....RA0069Outputsignal:Speciedonthecalibratorforreferenceconditions.Referenceconditions:Ambienttemperature:................20°CAmbientpressure:................101.3kPaHumidity:........................65%RHEffectiveloadvolume:............250mm3Accuracy:SPL:............114dB±0.2dBre.20µPaFrequency:................1000Hz±0.2%ComplieswithIEC942-1988Class1.General:Typicalsensitivitytochangeinloadvolume:........0.0003dB/mm3at1000HzTimeforleveltostabilize:........max.2sec.Microphonesizes:AccordingtoIEC1094-4Withadaptersremoved:............1-inchWithadapter(s):............1⁄2-inchand1⁄4-inchHarmonicdistortion:Maximum:............................1%Controls:Push-buttonstart.Automaticswitch-off.CEclassication:EMC:............EN50081-1,EN50082-1Safety:................EN61010-1,1993Forportableequipment,pollutioncategory2.Specications