saej994v002

SAETechnicalStandardsBoardRulesprovidethat:“ThisreportispublishedbySAEtoadvancethestateoftechnicalandengineeringsciences.Theuseofthisreportisentirelyvoluntary,anditsapplicabilityandsuitabilityforanyparticularuse,includinganypatentinfringementarisingtherefrom,isthesoleresponsibilityoftheuser.”SAEreviewseachtechnicalreportatleasteveryfiveyearsatwhichtimeitmaybereaffirmed,revised,orcancelled.SAEinvitesyourwrittencommentsandsuggestions.Copyright©2003SAEInternationalAllrightsreserved.Nopartofthispublicationmaybereproduced,storedinaretrievalsystemortransmitted,inanyformorbyanymeans,electronic,mechanical,photocopying,recording,orotherwise,withoutthepriorwrittenpermissionofSAE.TOPLACEADOCUMENTORDER:Tel:877-606-7323(insideUSAandCanada)Tel:724-776-4970(outsideUSA)Fax:724-776-0790Email:custsvc@sae.orgSAEWEBADDRESS:http://www.sae.orgSURFACEVEHICLESTANDARDJ994REV.OCT2003Issued1967-07Revised2003-10SupersedingJ994MAR93Alarm—Backup—ElectricLaboratoryPerformanceTestingForeword—Thisdocumenthasbeenmodifiedtoincludeadditionalsystemvoltagesandreducetheupperlimitoftheacceptablefrequencyrange.AdditionalmodificationshavebeenmadetoclarifyambiguoussectionsoftheStandard.Rationaleforthemodificationsisincludedattheendofthisdocument.1.Scope—ThescopeofthisSAEStandardisthedefinitionofthefunctional,environmental,andlifecycletestrequirementsforelectricallyoperatedbackupalarmdevicesprimarilyintendedforuseonoff-road,self-propelledworkmachinesasdefinedbySAEJ1116(limitedtocategoriesof1)construction,and2)generalpurposeindustrial).1.1Purpose—Thepurposeofthisdocumentistodefineasetofperformancerequirementsforbackupalarms,independentofmachineusage.Thelaboratorytestsdefinedinthisdocumentareintendedtoprovideauniformandrepeatablemeansofverifyingwhetherornotatestalarmmeetsthestatedrequirements.Foronmachinerequirementsandtestprocedures,refertoSAEJ1446.2.References2.1ApplicablePublications—Thefollowingpublicationsformapartofthespecificationtotheextentspecifiedherein.Unlessotherwiseindicated,thelatestrevisionofSAEpublicationsshallapply.2.1.1SAEPUBLICATIONS—AvailablefromSAE,400CommonwealthDrive,Warrendale,PA15096-0001.SAEJ184—QualifyingaSoundDataAcquisitionSystemSAEJ1116—CategoriesofOff-RoadSelf-PropelledWorkMachinesSAEJ1446—On-MachineAlarmTestandEvaluationProcedureforConstructionandGeneralPurposeIndustrialMachinery2.1.2ANSIPUBLICATIONS—AvailablefromANSI,25West43rdStreet,NewYork,NY10036-8002.ANSIS1.4—SpecificationforSoundLevelMetersANSIS1.40—SpecificationforAcousticalCalibrators2.1.3ASTMPUBLICATION—AvailablefromASTM,100BarrHarborDrive,WestConshohocken,PA19428-2959.ASTMB117—MethodofSaltSpray(Fog)TestingSAEJ994RevisedOCT2003-2-2.1.4MILSPECIFICATION—AvailablefromDefensePrintingService,DetachmentOffice,700RobbinsAvenue,Building4D,Philadelphia,PA19111-5094.MIL-STD-810B—EnvironmentalTestMethods510and514.12.2RelatedPublications—Thefollowingpublicationsareprovidedforinformationpurposesonlyandarenotarequiredpartofthisdocument.2.2.1SAEPUBLICATIONS—AvailablefromSAE,400CommonwealthDrive,Warrendale,PA15096-0001.SAEJ1105—Performance,TestandApplicationofElectricForwardWarningHornSAEJ1211—RecommendedEnvironmentalPracticesforEnvironmentalElectronicEquipmentSAEJ1455—RecommendedEnvironmentalPracticesforElectronicEquipmentDesign(Heavy-DutyTrucks)SAEJ1849–EmergencyVehicleSirens2.2.2ANSIPUBLICATIONS—AvailablefromANSI,25West43rdStreet,NewYork,NY10036-8002.ANSIS1.1—AcousticalTerminologyANSIS1.13—MethodsfortheMeasurementofSoundPressureLevel3.Definitions3.1FreeField—Afreefield,forthepurposesofthisdocument,isdefinedasaspacewithnoreflectingsurfacewithin15mofthesoundsourceinanydirection.3.2HorizontalReflectingPlane—Ahorizontalreflectingplaneisdefinedasflatgroundwithasurfacenorougherthananasphaltroad.Apavedparkinglotwithnoreflectingsurfaceswithin15mwouldbeanacceptablehorizontalreflectingplaneforthetestsoutlinedinthisdocument.3.3ZeroDegreeAxis—Alineknownasthe“zerodegreeaxis”isdefinedtocorrespondtothecenterlineofthesoundproducer,perpendiculartoandextendingoutwardfromtheoutputfaceofthealarm.3.4SampleAlarm—Asamplealarmshallconsistofanalarmrandomlydrawnfromtheproductionpopulation.3.5PredominantSoundFrequency—ThepredominantsoundfrequencyofthealarmshallbedefinedasthefrequencythatproducesthehighestA-weightedsoundpressurelevel.Thisfrequencymayormaynotcorrespondtothefundamentalfrequencyproducedbythealarm.3.6TestVoltages—Thenominal,extremelow,andextremehighsystemtestvoltagesaredefinedforeachsystemvoltageinTable1.Allvoltagesare±0.2V,measuredattheinputterminalsofthealarmwhenthealarmisoperating.3.6.1TESTVOLTAGETABLENOTE—Onmulti-voltagealarms,usetheextremelowsystemvoltagefromthelowestsystemvoltageincludedinthemulti-voltagerange,andtheextremehighsystemvoltagefromthehighestincludedvoltagerange,andallincludednominalvoltages,unlessotherwisespecified.SAEJ994RevisedOCT2003-3-TheExtremeHighSystemVoltagesforSystemVoltagesof36,48,72,and80voltsareequaltotheNominalSystemVoltagesbecausethesearebatterypowered(e.g.,forklifts)andwillnotbesubjectedtopossiblealternatorfailurescausingexcessivelyhighvoltagesasinthe12,24,and42voltinternalcombustionelectricalsystems.3.7TestSequence—Allfunctionalandperformancetestsshallbeconductedintheorderinwhichtheyarepresented.ThesamesamplealarmshallbeusedforalloftheFunctional,Environmental,andLifeTests.4.Instrumentation—Personstechnicallytrainedandexperiencedincurrenttechniquesofsoundmeasurementshouldselectandoperatetheequipment.SoundEngineeringjudgment,includinganassessmentofthe“state-of-the-art”withrespecttotestequipment,facilities,andtestpersonnel,shouldbeusedwhenestablishingspecifictestproceduresusedtoverifycompliancewiththerequirementsofthisstandard.Whensingle-sidedtestparametersarespecified,suchas“minimum”,“maximum”,and“atleast”,itisintendedthattherequiredspecificparameterbemet,withtheconstraintthatdeviationsfromthenominalparametervalue(ontheopen-endedside)beminimized.Whennon-specificparametertolerancesareused,suchas“approximately”,itisintendedthatdeviationsfromthenominalparameterbeminimized.4.1AsoundlevelmeterwhichmeetstheTypeIrequirementsofANSIS1.4.4.2Asanalternativetomakingdirectmeasurementsusingasoundlevelmeter,amicrophoneorsoundlevelmetermaybeusedwithamagnetictaperecorderand/oragraphiclevelrecorderorindicatormeter,providedthesystemmeetstherequirementsofSAEJ184,forthefrequencyrangethatisofprimaryconcern.Thedeviationsinthemagnetictaperecorderfrequencyresponsefromflatresponse,especiallyatlowerfrequencies,mustnotaffecttheoverallreadingbymorethan±0.5dB.4.3AsoundpressurelevelcalibratormeetingtherequirementofANSIS1.40(accuracywithin±0.5dB).4.4Atemperaturemeasuringsystemaccurateto±0.5°Covertherangeof–40to+85°C.4.5Avoltagemeasuringsystemaccurateto±100mVovertherangeofextremesystemvoltagesforthetestedsystemvoltage(s).4.6Vibrationapparatus.4.7Environmentalchamber.4.8Dustchamber.TABLE1—TESTVOLTAGESSystemVoltage(1)1.IC–InternalCombustionE–Electric(BatteryPowered)NominalSystemVoltageExtremeLowSystemVoltageExtremeHighSystemVoltage12(IC)14.09.016.024(IC)28.018.032.036(E)42.027.042.042(IC)(2)2.NewEuropeanElectricalSystem49.032.056.048(E)56.036.056.072(E)84.054.084.080(E)94.060.094.0SAEJ994RevisedOCT2003-4-4.9Rain,steam,andcorrosionchamber.5.SoundPressureLevelTestSetup—SoundpressurelevelTest-Twoacceptabletestmethodswillbedescribedformeasuringalarmsoundpressurelevel.5.1TestMethod1—Thealarmislocatedinafreefieldoranequivalentfullyanechoicroom.Themicrophoneisdirectedtowardthealarmsoundoutputopeningalongthezerodegreeaxisandatthedistancespecifiedbythetestrequirements.5.2TestMethod2—Thisisanalternativemethodfortestinganalarmsoundpressurelevelwithouttheaidofananechoicroom.Thealarmislocatedinafreefieldexceptforahorizontalreflectingplaneandanacousticalbarrierpartition.Theacousticalbarrierpartitionmustbeconstructed.5.2.1REQUIREDMATERIALSFORACOUSTICALBARRIER—Unlessotherwisespecified,alldimensionaltolerancesare±10mm.a.Twopiecesofparticleboard900mmx1200mmx16mm±2mmthickb.TwoTripodsadjustableto1200mmhighc.Threeeach200mmx200mmx90degreesheetmetalshelfbrackets.d.Twosectionsofsoundabsorbingfoamofdimensions1200mmx1350mmandathicknessof50mmorgreater.Thesoundabsorbingfoamshouldhaveanabsorptionefficiencyofatleast50%at50Hzrisingtoatleast75%at1000Hzandgreater.5.2.2CONSTRUCTIONOFACOUSTICALBARRIER—Usingthethree200mmshelfbracketsandscrews,centerandattachoneofthe900mmx1200mmparticleboardsperpendiculartotheother900mmx1200mmbaseboardtoyielda900mmhighwallasshowninFigure1.Twobracketsshouldbelocated150mmfromtheoutsideedgeononesideoftheuprightboard.Thethirdbracketshouldbemountedinthecenterontheothersideoftheuprightboard.CovertheexposedparticleboardwiththesoundabsorbingfoamasshowninFigure1.5.2.3ALARMANDMICROPHONELOCATIONS—Securethealarmandmicrophonetotheirtripods.Positionthealarmandmicrophoneonoppositesidesofandequidistantfromthesoundbarrierataheightof1200mm±10mmabovethehorizontalreflectingplane.Thedistancebetweenthetwodevicesisspecifiedin6.3oftheFunctionalTestRequirements.5.3AllowableBackgroundNoiseLevel—Whilethesoundpressureleveltestisinprogress,thesoundpressurelevelduetoallsourcesotherthanthealarmdeviceshallbeatleast15dB(A)lowerthanthesoundpressurelevelofthealarm.Thisprecautionreducestheeffectofbackgroundnoiseonthesoundpressureleveltestresults.5.4SoundLevelMeterSettings—ThesoundlevelmetershallbesetforfastresponseorequivalentandhavetheA-weightingnetworkinstalledwhencheckingsoundpressurelevels.5.5InstrumentationPrecautions—Properusageofalltestinstrumentationisessentialtoobtainvalidmeasurements.Operatingmanualsorotherliteraturefurnishedbytheinstrumentmanufacturershouldbereferredtoforbothrecommendedoperationoftheinstrumentandprecautionstobeobserved.Specificitemstoreviewinclude:5.5.1THEMICROPHONE—Thetypeofmicrophone,itsdirectionalresponsecharacteristics,anditsorientationrelativetothegroundplaneandsourceofnoise.5.5.2CALIBRATION—Fieldcalibrationshouldbemadeimmediatelybeforeandaftereachtestsequence.Internalcalibrationmeansareacceptableforfielduse,providedthatexternalcalibrationisaccomplishedimmediatelybeforeorafterfielduse.SAEJ994RevisedOCT2003-5-FIGURE1—ACOUSTICALBARRIERDIMENSIONSFORTESTMETHOD25.5.3WINDSCREENS—Whenusingawindscreen,itshouldbecalibratedforthetypeofnoisesourcebeingmeasuredanddatacorrectedifnecessary.Itisrecommendedthatmeasurementsbemadeonlywhenthewindspeedisbelow19km/h.SAEJ994RevisedOCT2003-6-6.FunctionalTestRequirements—Unlessotherwisespecified,datameasurementswillbetakenduringaminimumtestperiodof1minoperationatambienttemperatureof25°C±11°Candnominalsystemvoltage(s)(±0.2VDC)forthetestedsystemvoltage(s)inTable1.6.1PredominantSoundFrequency—Measureandrecordthepredominantsoundfrequencyofthealarm.ThepredominantsoundfrequencyofthealarmshallbedefinedasthefrequencythatproducesthehighestA-weightedsoundpressurelevel.Theacceptablefrequencyrangeis700to2800Hz.6.2CyclicPulsationRateandDutyCycle—Measureandrecordtherateofcyclicsoundpressurelevelpulsationsfromthealarmandthedurationofthe“on”and“off”intervals.Thecyclesofsoundpressurelevelpulsationsfromthealarmshallbe0.8to1.8Hz.Thedurationofthe“on”intervalshallbeequaltothatofthe“off”intervalwithin±20%,asdefinedbytheformula:(“on”intervalminus“off”interval)dividedby(“on”intervalplus“off”interval),multipliedby100%.6.3Soundpressurelevel—Measureandrecordthesoundpressurelevelofthealarmatallnominalsystemvoltagesincludedinthevoltagerangeofthealarmusingthemethodsof5.1or5.2.Themicrophoneshallbeplacedonthezeroaxisofthealarmatadistanceof1.2m±0.01mfromthefrontfaceofthealarm.Thesoundpressurelevelshallbeanyofthefollowing:TypeA-112dB(A)TypeB-107dB(A)TypeC-97dB(A)TypeD-87dB(A)TypeE-77dB(A)TypeF–Other(SoundpressurelevelratingindB(A)mustbeimprintedonthealarm.)Unlessotherwisestated,thetoleranceonsoundpressurelevelmeasurementsis±4dB(A).InthecaseofaTypeFalarm,theManufacturer’sstatedsoundpressurelevelshallserveasthenominaldB(A)ratingtowhichthe±4dBtoleranceisappliedto.6.4SoundPressureLevelChangeWithVoltage—Measureandrecordthesoundpressurelevelattheextremeoperatingvoltagesforthetestedsystemvoltage(s)inTable1.Thesoundpressurelevelshallnotvarymorethan±8dBfromthebaselinedatagivenin6.3.6.5Off-AxisSoundLevels6.5.1HORIZONTALMOUNTINGSURFACE—Allsoundpressurelevelmeasurementsaremadeataradiusof1.2m±0.01mfromthesoundproducer.Theinitialmeasurementisonthezerodegreeaxis.Twelveadditionalmeasurementsaretakenat15degrees±2degreeintervalsfrom–90to+90degreesthroughthehorizontalplanebyrotatingthealarmasshowninFigure2.Foreachlocationdescribedpreviously,measurethesoundpressurelevelusingeitherTestMethod1orTestMethod2ofSection5.RecordthedatainColumn2,theformshowninFigure3.ThevaluesrecordedinColumn3oftheformareobtainedbysubtractingthesoundpressurelevelatthezerodegreeaxisfromthesoundpressurelevelateachangularposition.ThedatafromColumn3isplottedonthechartofFigure4toobtaintheprofileofsoundvariationasafunctionofdirectionfromthealarm.Fillintheblanksandchecktheappropriateboxesatthetopsoftheformandtheprofilesheets.SAEJ994RevisedOCT2003-7-FIGURE2—BACKUPALARMSOUNDPRESSURELEVELMEASUREMENTLOCATIONS—MOUNTINGSURFACEHORIZONTAL6.5.2VERTICALMOUNTINGSURFACE—Thealarmisnextrotated90degreesaboutthezeroaxis,asshowninFigure5.Repeattheprocedureof6.5.1.Thisdocumentdoesnotspecifyanylimitationsonsoundvariationasafunctionofdirectionfromthealarmbutdoesrequirethatthesoundvariationprofilesbemadeavailableuponrequest.6.6AlarmActivationDelay—Measureandrecordthedelaybetweenpowerapplicationandalarmactivation.TheAlarmActivationDelayshallbedefinedbythetimedifferencebetweenpowerapplicationtotheinputterminalsofthealarmandelectricalsignalappearingacrosstheterminalsofthesoundtransducer.TheAlarmActivationDelayshallbenomorethan500ms.7.EnvironmentalTests—Unlessotherwisespecified,alldatameasurementswillbetakenduringaminimumtestperiodof1minoperationatambienttemperatureof25°C±11°Candnominalsystemvoltage(s)(±0.2VDC)forthetestedsystemvoltage(s)inTable1.7.1LowTemperatureTest—Temperaturesoakthealarmintheenvironmentalchamberat40°C±3°Cforaminimumof2hourspriortothefollowingtests.Removethealarmfromtheenvironmentalchambertomakemeasurements.Unlessotherwisespecified,itisrequiredthatthefollowingmeasurementsbemadewithin2minutesofremovingthealarmfromtheenvironmentalchamber.Ifallrequiredmeasurementscannotbemadewithinthe2minuteallottedtimeinterval,thetemperaturesoakmustberepeatedforanadditional1hourpriortoproceedingwithadditionalmeasurements.7.1.1LOWTEMPERATURE,NOMINALSYSTEMVOLTAGE—Within2minutesafterremovingthealarmfromtheenvironmentalchamber,measureandrecordthesoundpressurelevelandpredominantsoundfrequencyofthealarmforallincludednominalsystemvoltageswithinthevoltagerangeofthealarm.Thesoundpressurelevelmustbewithin±8dB(A)ofthebaselinedatameasuredin6.3.Thepredominantsoundfrequencymustbewithintherangespecifiedin6.1.SAEJ994RevisedOCT2003-8-FIGURE3—BACKUPALARMSOUNDPRESSURELEVELDATASHEETSAEJ994RevisedOCT2003-9-FIGURE4—SOUNDPRESSURELEVELDIRECTIONALITYCHARTSAEJ994RevisedOCT2003-10-FIGURE5—BACKUPALARMSOUNDPRESSURELEVELMEASUREMENTLOCATIONS—MOUNTINGSURFACEVERTICAL7.1.2LOWTEMPERATURE,SYSTEMVOLTAGEEXTREMES—Within2minafterremovingthealarmfromtheenvironmentalchamber,measureandrecordthesoundpressurelevelandpredominatesoundfrequencyofthealarmforbothextremesystemvoltagesforthetestedsystemvoltage(s)inTable1.Thesoundpressurelevelshallbewithin±8dB(A)ofthebaselinedatafortherespectivenominalsystemvoltage(s)measuredin6.3thatareclosesttotheextremesystemvoltage(s).Repeat6.1.Thepredominantsoundfrequencyshallbewithinthefrequencyrangespecifiedin6.1.7.1.3ROOMTEMPERATURECHECK—Subsequenttoperformingthemeasurementsin7.1.1and7.1.2,allowthealarmtowarmupto25°C±11°Cforaminimumof1hour.Repeat6.1and6.3.Thealarmshallmeetthesoundpressurelevelrequirementsof6.3.Thepredominantsoundfrequencyshallbewithinthefrequencyrangespecifiedin6.1.7.2HighTemperatureTest—Temperaturesoakthealarmintheenvironmentalchamberat85°C±3°Cforaminimumof2hourspriortothefollowingtests.Removethealarmfromtheenvironmentalchambertomakemeasurements.Unlessotherwisespecified,itisrequiredthatthefollowingmeasurementsbemadewithin2minutesofremovingthealarmfromtheenvironmentalchamber.Ifallrequiredmeasurementscannotbemadewithinthe2minuteallottedtimeinterval,thetemperaturesoakmustberepeatedforanadditional1hourpriortoproceedingwithadditionalmeasurements.7.2.1HIGHTEMPERATURE,NOMINALSYSTEMVOLTAGE—Within2minutesafterremovingthealarmfromtheenvironmentalchamber,measureandrecordthesoundpressurelevelandpredominantsoundfrequencyofthealarmforallincludednominalsystemvoltageswithinthevoltagerangeofthealarm.Thesoundpressurelevelshallbewithin±8dB(A)ofthebaselinedatameasuredin6.3.Repeat6.1.Thepredominantsoundfrequencyshallbewithintherangespecifiedin6.1.SAEJ994RevisedOCT2003-11-7.2.2HIGHTEMPERATURE,SYSTEMVOLTAGEEXTREMES—Within2minutesafterremovingthealarmfromtheenvironmentalchamber,measureandrecordthesoundpressurelevelandpredominantsoundfrequencyofthealarmfortheextremesystemvoltagesforthetestedsystemvoltage(s)inTable1.Thesoundpressurelevelshallbewithin±8dB(A)ofthebaselinedatafortherespectivenominalsystemvoltage(s)measuredin6.3thatareclosesttotheextremesystemvoltage(s).Repeat6.1.Thepredominantsoundfrequencyshallbewithinthefrequencyrangespecifiedin6.1.7.2.3ROOMTEMPERATURECHECK—Subsequenttoperformingthemeasurementsin7.2.1and7.2.2,allowthealarmtocoolto25°C±11°Cforaminimumof1hour.Repeat6.1and6.3.Thealarmshallmeetthesoundlevelrequirementsof6.3.Thepredominantsoundfrequencyshallbewithintherangespecifiedin6.1.7.3RainTest—Mountasamplealarm,notinoperation,suchthatthezeroaxisofthealarmishorizontal.Subjectallexposedsidesofthealarmitemtosimulatedblownrainforaminimumof2hours.Simulatedblownrainisdefinedashavingwithaprecipitationrateof2.5(+1.6/–0)mmwaterperminute(asmeasuredwithaverticalcylindricalcollectorhavingaheightofapproximately100mmandtheinsidediametershallbeaminimumof140mm,centeredontheverticalaxisofthetestplatform),deliveredatanangleof45degreesfromanozzlewithasolidconespray.Within1minafterremovalfromtheraintest,repeat6.1and6.Thesoundpressurelevelshallmeettherequirementsof6.3.Thepredominantsoundfrequencyshallbewithinthefrequencyrangespecifiedin6.1.7.4VibrationTest—Asamplealarm,asmountedonthesupportssupplied,shallbeboltedtothetableofthevibrationtestmachineandthetestconductedasfollowswiththealarminoperation.7.4.1RESONANCESEARCH—Determineandrecordtheresonantfrequenciesofthetestitemforeachposition(x-y-zaxis)byslowlyvaryingthefrequencyofappliedvibrationthrough10to500Hzwithsufficientamplitudetoexcitetheitem.Resonanceofcomponentsisdeterminedbyvisualobservation,strain-gagingofcomponents,observingsignalinterruptionsoftheelectroniccircuit,oracombinationofthese.SeeFigure6.7.4.2RESONANCEDWELL—Vibratethetestitemfor30minata10g(peaktopeak)levelatthemostsevereresonantfrequencyandatnomorethanthreeothersignificantresonantfrequencies(iftheywerefound)alongeachaxisasdeterminedin7.4.1.Forresonantfrequenciesbelow27Hz,vibrateataconstantamplitudeof6.76mmasshowninFigure6.Iftheresonancefrequencychangesduringthistest,immediatelyrecorditstimeofoccurrenceandadjustthefrequencytomaintainpeakresonance.Recordfinalresonancefrequency.7.4.3VIBRATIONCYCLING—Useacycletimeof15mintoascendto500Hzanddescendto27Hz(refertoFigure6).Vibrationcyclingwillbealongeachaxis(x-y-z)at10g(peaktopeak)above27Hz.Thetotalcyclingtimeforeachaxisis3hminusthetimespentontheaxisfortheresonantdwelltestin7.4.2(MIL-STD-810BMethod514.1).Duringthefinal15minutecycle(onax