1、A Referencenumbe r ISO134751:1999(E) INTERNATIONAL STANDARD ISO 134751 Firstedition 19991115 AcousticsStationaryaudiblewarning devicesusedoutdoors Part1: Fieldmeasurementsfordetermination ofsoundemissionquantities AcoustiqueDispositifsdalarmesonorefixesutilisslextrieur Partie1:Mesuragessurleterraind
2、esgrandeursdmissionacoustiqueISO134751:1999(E) ISO1999 Allrightsreserved.Unlessotherwisespecified,nopartofthispublicationmaybereproducedorutilizedinanyformorbyan ymeans,electronic ormechanical,includingphotocopyingandmicrofilm,withoutpermissioninwritingfromthepublisher. InternationalOrganizationforS
3、tandardization Casepostale56 CH1211Genve20 Switzerland Internet isoiso.ch PrintedinSwitzerland ii Contents 1Scope . 1 2Normativereferences .1 3Termsanddefinitions . .1 4 Testconditions .3 4.1Testsite . .3 4.2Mountingofapparatus . .3 4.3Instrumentation. .3 4.4Microphonepositions .4 4.5Measurementmeth
4、ods. .4 4.6Ambientconditions .8 4.7Testprocedure .8 5Acousticcharacteristics 8 5.1Testsignals 8 5.2Durationofthemeasurement. 9 5.3Determinationofthesoundemissionquantities .9 5.4Measurementuncertainty . 10 6Informationtobereported .10 AnnexA (normative) Supplyconditions 14 AnnexB (normative) Calcula
5、tionofcombinedexpandeduncertainty.15 Bibliography19ISO ISO134751:1999(E) iii Foreword ISO(theInternationalOrganizationforStandardization)isaworldwidefederationofnationalstandardsbodies(ISO memberbodies).TheworkofpreparingInternationalStandardsisnormallycarriedoutthroughISOtechnical committees.Eachme
6、mberbodyinterestedinasubjectforwhichatechnicalcommitteehasbeenestablishedhas therighttoberepresentedonthatcommittee.Internationalorganizations,governmentalandnongovernmental,in liaisonwithISO,alsotakepartinthework.ISOcollaboratescloselywiththeInternationalElectrotechnical Commission(IEC)onallmatters
7、ofelectrotechnicalstandardization. InternationalStandardsaredraftedinaccordancewiththerulesgivenintheISO/IECDirectives,Part3. DraftInternationalStandardsadoptedbythetechnicalcommitteesarecirculatedtothememberbodiesforvoting. PublicationasanInternationalStandardrequiresapprovalbyatleast75%ofthemember
8、bodiescastingavote. InternationalStandardISO134751waspreparedbyISO/TC43, Acoustics,SubcommitteeSC1, Noise . ISO13475consistsofthefollowingparts,underthegeneraltitle AcousticsStationaryaudiblewarningdevices usedoutdoors : Part1:Fieldmeasurementsfordeterminationofsoundemissionquantities Part2:Testroom
9、measurements Part3:Outdoorpropagationofwarningsignalsoverbuiltupareas AnnexesAandBformanormativepartofthispartofISO13475.ISO134751:1999(E) ISO iv Introduction ISO134751describesfieldmeasurements.Thetestmethodsareintendedtoproducefieldtestvaluesofthesound emissionlevelofasirenasitisinstalledinanoutdo
10、orsituation.Thesefieldtestvaluesmay,togetherwiththe statedmeasurementuncertainties,beusedtocheckthespecificationsofdeliveredsirensortocomparethe performanceofdifferentsirensunderthesameconditions,emittingthesamesignals. ISO134752describesprecisionmeasurements. Thismethodisintendedtoproduceagenerally
11、validspecification ofsirensfortypetests,acceptancetests,orforuseinthedesignofoutdoorwarningsystems,etc. Inpart1ofISO13475,twotypesoffieldmeasurementsarediscussed.Theyare: a) Flatplatemeasurements: thismethodusesamicrophoneplacedonaflatplatewhichislocatedonthe ground.Duringthemeasurement,theintendedm
12、ainsoundradiationpatternofthewarningdevicesistilted towardthemicrophoneandplateassembly. b)Horizontal measurements: thismethodisperformedwiththemicrophoneplacedatthesameelevationasthe centreoftheaudiblewarningdevice(atapreferredheightof10m). Measurementsmadeunderoptimalconditionsinconformitywiththis
13、partofISO13475shouldresultinstandard uncertaintiesequaltoorlessthanthevaluesgiveninTable1.Thestandarduncertaintyforactualmeasurement conditionstakingintoaccountthecumulativeeffectofallcausesofmeasurementuncertaintyaretreatedinparts1 and2ofISO13475. Table1UncertaintyindeterminingimmissionrelevantCwei
14、ghtedsoundpowerlevels forstationaryaudiblewarningdevices Reference Measurementmethod Expectedexpanded uncertainty Part1:Fieldmeasurements Flatplate 2dB Horizontal 4dB Part2:Precisionmeasurements 1dBINTERNATIONALSTANDARD ISO ISO134751:1999(E) 1 AcousticsStationaryaudiblewarningdevicesusedoutdoors Par
15、t1: Fieldmeasurementsfordeterminationofsoundemissionquantities 1Scope ThispartofISO13475specifiesthetestconditionsbywhichthesoundemissionlevelofstationaryaudiblewarning devicescanbeobtained.Themethodsareapplicabletosirensforuseinpublicoutdoorwarningsystemsand soundsignallingdevicesforuseoutdoors. Th
16、epurposeofthistestcodeistobeabletoproducereliablesoundemissionlevelmeasurementsforstationary sirensusedforwarningoutdoors. ThispartofISO13475doesnotcoverspokenmessagesandcontainsnorecommendationsforspecificwarning signals. 2Normative references Thefollowingnormativedocumentscontainprovisionswhich,th
17、roughreferenceinthistext,constituteprovisionsof thispartofISO13475.Fordatedreferences,subsequentamendmentsto,orrevisionsof,anyofthesepublications donotapply.However,partiestoagreementsbasedonthispartofISO13475areencouragedtoinvestigatethe possibilityofapplyingthemostrecenteditionsofthenormativedocum
18、entsindicatedbelow.Forundated references,thelatesteditionofthenormativedocumentreferredtoapplies.MembersofISOandIECmaintain registersofcurrentlyvalidInternationalStandards. IEC60651 1) , Soundlevelmeters. IEC60804 1) , Integratingaveragingsoundlevelmeters. IEC60942, Soundcalibrators . IEC61260, Octa
19、vebandandfractionaloctavebandfilters. 3 Termsanddefinitions ForthepurposesofthispartofISO13475,thefollowingtermsanddefinitionsapply. 3.1 siren audiblewarningdeviceforuseoutdoors 1) ThesewillberevisedandcombinedasIEC61672.ISO134751:1999(E) ISO 2 3.2 electronicsiren sirenthatproducestonalsoundsbyampli
20、fyingtheoutputofanelectronicsignalgeneratorandbroadcastingthe amplifiedsignalfromoneormoreelectrodynamicloudspeakers NOTE Suchsirensmayalsobeusedforgivingvoicemessages. 3.3 electromechanicalsiren sirenthatproducestonalsoundsbyflowinterruptionsgeneratedinarotatingwheel NOTE Electromechanicalsirensare
21、mechanicalsirensdrivenbyanelectricmotor. 3.4 pneumaticsiren sirenthatproducessoundbyperiodicallyinterruptingormodulatingaflowofcompressedair NOTE Theaircompressormaybeintegralwithorseparatefromtheflowinterrupter. 3.5 horizontallyomnidirectionalsiren sirenthatradiatessoundapproximatelyuniformly(withi
22、naspecifiedtolerance)inallhorizontaldirectionsfromthe sirenatthespecifiedfrequencyofthesound 3.6 directionalsiren sirenthatradiatesmostofitssoundinoneormorespecificdirections 3.7 rotatingoroscillatingsiren directionalsirenthatcontainsamechanismwhichslowlyrotatesitsbeamofsoundaboutaverticalaxis 3.8 i
23、mmissionrelevantsoundpowerlevel L W,imm soundpowerlevelfromamonopolesourcethatwouldgivethesamesoundpressurelevelinthefarfieldasthe actualsource NOTE Itisexpressedindecibels(dB). Table2Symbols Symbol Definition Unit L p Soundpressurelevel,ref.20 mPa dB L pC CWeightedsoundpressurelevel,ref.20 mPa dB L
24、 pCmax,F MaximumCweightedsoundpressurelevel,measuredwithtimeweightingF accordingto4.5.3 dB L pCeq,T EquivalentCweightedsoundpressureleveloveratimeperiodT dB L W,imm Immissionrelevantsoundpowerlevel,ref.1pW dB L WC,imm CWeightedimmissionrelevantsoundpowerlevel,ref.1pW dBISO ISO134751:1999(E) 3 4Test
25、conditions 4.1Test site Thegroundsurfacebetweenthesirenandthemicrophoneshallbeflattowithin 1,0m. Thesurfacebetweenthewarningdeviceandthemicrophonemaybecoveredwithgrassand/orpavement.There shallbenosoundreflectingobject(e.g.buildingwallsorroofs)withinthehorizontalplanecontainingthebaseofthe soundsour
26、cethatarecloserthantwicethemeasurementdistancefromthesource. Allstructureswithinthreetimesthemeasurementdistancefromboththesourceandthemicrophoneshallbe described. NOTE Allsurfacesnearthesoundsourcewillreflectsoundand,dependingontheirmaterial,location,andorientationmay biastheresultsofthemeasurement
27、s.Theintentofabovespecificationsistominimizetheeffectsofallreflectionsexceptt hose fromthegroundsurface.Theaccuracyofthefieldmeasurementsdependondistance,reflectingobjects,reflectionsoffthe ground,verticaldirectivity,nearfieldeffects,andinstrumentation.Thecontributionsofuncertaintyduetoreflectingsur
28、fa cecan becalculatedaccordingtotheprocedureinannexB. 4.2 Mountingofapparatus Thewarningsoundsourcetobetestedshallbelocatedatorabovethemanufacturersrecommendedinstallation heightabovetheground;seeFigures1and5andcorrespondingtext. Therecommendedheighttothecentreofthewarningdevice(acousticcentre)accor
29、dingtothispartofISO13475 is10mabovetheground.ThemountingshouldbecarriedoutinaccordancewiththispartofISO13475orthe manufacturersrecommendations. Whentheflatplatemeasurementmethodisused(see4.5),atiltisrecommendedforsirensthataredirectionalin theverticalplane.Thetiltshallbeatsuchananglethatthenormallyv
30、erticalsirenaxisisperpendiculartothe directiontothemicrophone.Ifnottilted,themeasuredvaluesshallbecorrectedusingtheverticaldirectional characteristics(seeannexB). PowersupplyconditionsshallbeinaccordancewithannexA. 4.3Instrumentation 4.3.1Acoustical instruments 4.3.1.1 Equipmentfordeterminationofthe
31、soundpressurelevel Thesoundlevelmeterortheequivalentmeasuringsystem,includingthewindshieldasrecommendedbythe manufacturer,shallfulfiltherequirementsofaclass1orclass2soundlevelmeteraccordingtoIEC60651and IEC60804.Thediameterofthemicrophoneshallbelessthanorequalto13mm,whenusingtheflatplatemethod (see4
32、.5.2). 4.3.1.2 Equipmentfortheoptionaldeterminationofoctaveandonethirdoctavebandspectra ThefiltersshallmeettherequirementsofIEC61260,class1orclass2;parallelfiltersarepreferred. Theequivalentcontinuoussoundpressurelevelsshallbedeterminedsimultaneouslyinoctaveoronethirdoctave bandswithcentrefrequencie
33、sfrom50Hzto4000Hz. 4.3.1.3 Calibrationofthemeasurementsetup Thecalibrationofthecompletesoundmeasuringsystem,includinganyrecording,datalogging,puting systems,shallbecheckedimmediatelybeforeandafterthemeasurementsessionatoneormorefrequenciesusing asoundcalibrator.Thecalibratorshallfulfiltherequirement
34、sofIEC60942,class1orclass2,andshallbeused withinitsspecifiedenvironmentalconditions.ISO134751:1999(E) ISO 4 Ifadifferenceof1,0dBormoreappearsbetweensubsequentcalibrationsessions,theinstrumentsshallbe checkedandthemeasurementsshallberejected. 4.3.1.4 Calibrationoftheequipmentanditstraceability Allequ
35、ipmentforsoundmeasurementsshallbecheckedregularlyandshallbecalibratedwithtraceabilityto nationalstandards.Calibrationintervalsforsoundcalibratorsshouldbe12monthsandforotherequipment 24months. 4.4Microphone positions Microphonepositionsarechoseninaccordancewiththemeasurementmethod. Windshieldsshallbe
36、usedduringallmeasurements. Thereferencedistancebetweenthesirencentreandthemicrophoneis30m.Themaximumdistancebetweenthe sirenandthemicrophoneshallnotexceed50m. Foroptimizingthemeasurementdistance,uncertaintiesarisingfromnearfieldeffectsandgroundeffectsshallbe takenintoconsideration;seeannexB. 4.5Meas
37、urement methods 4.5.1General Twomethodsaredescribed:theflatplatemethodandthehorizontalmeasurementmethod. Theflatplatemethodrequiresthemicrophonetobeplacedonaflatplateontheground.Thismethodresultsina 6dBincreaseofthesoundpressurelevelviathecontrolledreflectionoftheplate(relativetothefreefieldvalue).
38、However,inordertomeasuresoundpressurelevelsofdirectivesirens,themainsoundradiationpatternofthe sirenshallbedirectedtowardtheflatplate. Thehorizontalmeasurementmethodspecifiesthatthemicrophonebemountedatthesameelevationasthe warningdevice.Thismethodresultsinacombinedsoundpressuremeasurementofboththed
39、irectsoundpathand thereflectedsoundpath. 4.5.2Flatplate method ThemeasurementsetupissketchedinFigures1to4.Themicrophoneshallbeplacedontheplateaccordingto Figure1.TheflatplateandthemicrophonepositionshallbeinaccordancewithFigure4.Themicrophoneshallbe fixedtotheplateaccordingtoFigures2or3.Theplateshal
40、lbepaintedwhitetoavoidthermaleffects. Theangle a betweenthelineSM,seeFigure1,connectingthemicrophoneandthesirenandthehorizontalplane shallnotbelessthan10. Sincethismeasurementmethoddoublesthesoundpressuresrelativetofreefieldmeasurementsbecauseof reflectionsfromtheplate,6dBmustbesubtractedfromthesoun
41、dpressurelevelmeasured( L p,meas )ontheflat plate,accordingto5.3.1.ISO ISO134751:1999(E) 5 Key 1Siren 2Microphone 3Flatplate SM=30m Figure1Flatplatemeasurementsetup Dimensionsinmillimetres Key 1 Microphone 2 Steelwireof3mmdiameter,e.g.3pieces 3 Windshield 4 Metalplate,2,5mmthick Figure2Invertedmicro
42、phonelocationSideviewISO134751:1999(E) ISO 6 Key 1 Microphone 2 Windshield 3 Metalplate,2,5mmthick NOTE Windshieldsarecuttopurposeforthismeasurement. Figure3Microphoneonitsside Dimensionsinmetres Key 1 Microphonelocation 2 Metalplate,2,5mmthick 3 Warningdevice NOTE Windshieldsarecuttopurposeforthismeasurement. Figure4PositionofmicrophoneTopviewISO ISO134751:1999(E) 7 4.5.3Horizontal method ThemeasurementpointsforthehorizontalmeasurementmethodaredefinedinFigures5and6. Figure5showsthemicrophoneatadistancedfromthew
