1、ISOInternationalStandardISO13472-2Secondedition2025-05AcousticsMeasurementofsoundabsorptionpropertiesofroadsurfacesinsitu一Part2:SpotmethodforreflectivesurfacesAcoustiqueMesurageinsitudesproprietesd,absorptionacoustiquedesrevetementsdechausseesPartie2:MethodeponctuellepourIessurfacesreflechissantesRe
2、ferencenumberISO13472-2:2025(en)COPYRIGHTPROTECTEDDOCUMENTISO2025Allrightsreserved.Unlessotherwisespecified,orrequiredinthecontextofitsimplementation,nopartofthispublicationmaybereproducedorutilizedotherwiseinanyformorbyanymeans,electronicormechanical,includingphotocopying,orpostingontheinternetoran
3、intranet,withoutpriorwrittenpermission.PermissioncanberequestedfromeitherISOattheaddressbeloworISO,smemberbodyinthecountryoftherequester.ISOcopyrightofficeCP401Ch.deBlandonnet8CH-1214Vernier,GenevaPhone:+41227490111Email:copyrightiso.orgWebsite:www.iso.orgPublishedinSwitzerlandContentsPageForewordiv
4、Introductionv2 Normativereferences13 Termsanddefinitions11.1 Measurementprinciple31.2 Signalanalysis41.3 Insitufixture45 Testequipment55.1 Soundsource55.2 Testsignal55.3 ImPedanCetube55.3.1 Tubediameter55.3.2 Tubelengthandmicrophonepositions55.3.3 Microphones65.4 Insitutestfixturebetweenimpedancetub
5、eandtestsurface65.5 Signalprocessingsystem75.6 Thermc)meterandbarometer76 Measurementandanalysisrequirements76.1 StabiliZirlgthesystem76.2 CalibratiOnofthesystem.76.3 Referencemeasurement76.4 Measurementofaroadsurface76.6 One-thirdOCtaVebandabsorptionspectrum.97 Positioningoftheequipment97.1 Locatio
6、nofthemeasurementpositions97.1.1 TestsurfacessuchasthosemeetingISO10844requirements97.1.2 Regularroads97.2 Temperature98 Measurementandanalysisprocedure99 MeaSUremelltUIICertaiIItyrequirements1010 Testreport11Annex A (informative)Correctiononbaseofreferencemeasurement13Annex B (informative)Measureme
7、ntuncertainty14Annex C (informative)Alternativeprocedurestoimproveaccuracy17Annex D (informative)Insitutestfixture20ArlrIeXE(informative)EXaITlPleofatestreport22Bibliography.25ForewordISO(theInternationalOrganizationforStandardization)isaworldwidefederationofnationalstandardsbodies(ISOmemberbodies).
8、TheworkofpreparingInternationalStandardsisnormallycarriedoutthroughISOtechnicalcommittees.Eachmemberbodyinterestedinasubjectforwhichatechnicalcommitteehasbeenestablishedhastherighttoberepresentedonthatcommittee.Internationalorganizations,governmentalandnon-governmental,inliaisonwithISO,alsotakeparti
9、nthework.ISOcollaboratescloselywiththeInternationalElectrotechnicalCommission(IEC)onallmattersofelectrotechnicalstandardization.TheproceduresusedtodevelopthisdocumentandthoseintendedforitsfurthermaintenancearedescribedintheISO/IECDirectives,Part1.Inparticular,thedifferentapprovalcriterianeededforthe
10、differenttypesofISOdocumentshouldbenoted.ThisdocumentwasdraftedinaccordancewiththeeditorialrulesoftheISO/IECDirectives,Part2(seeWWW.iso.org/directives).ISOdrawsattentiontothepossibilitythattheimplementationofthisdocumentmayinvolvetheuseof（八）patent(三).ISOtakesnopositionconcerningtheevidence,validityo
11、rapplicabilityofanyclaimedpatentrightsinrespectthereof.Asofthedateofpublicationofthisdocument,ISOhadnotreceivednoticeof（八）patent(三)whichmayberequiredtoimplementthisdocument.However,Implementersarecautionedthatthismaynotrepresentthelatestinformation,whichmaybeobtainedfromthepatentdatabaseavailableatW
12、WW.iso.org/patents.ISOshallnotbeheldresponsibleforidentifyinganyorallsuchpatentrights.Anytradenameusedinthisdocumentisinformationgivenfortheconvenienceofusersanddoesnotconstituteanendorsement.Foranexplanationofthevoluntarynatureofstandards,themeaningofISOspecifictermsandexpressionsrelatedtoconformit
13、yassessment,aswellasinformationaboutISOsadherencetotheWorldTradeOrganization(WTO)principlesintheTechnicalBarrierstoTrade(TBT),seeWWW.iso.org/iso/foreword.htmLThisdocumentwaspreparedbyTechnicalCommitteeISO/TC43,Acoustics,SubcommitteeSC1,Noise.Thissecondeditioncancelsandreplacesthefirstedition(ISO1347
14、2-2:2010),whichhasbeentechnicallyrevised.Themainchangesareasfollows: mandatorychoiceofthetransferfunctionformulationandqualityrequirementsforthecoherencefunction; analternativemicrophonearrangementandapplicationofalternatingtransferfunctionsarepresentedtocancelthedistortionduetodestructiveinterferen
15、ceatthemicrophonepositions.AlistofallpartsintheISO13472seriescanbefoundontheISOwebsite.Anyfeedbackorquestionsonthisdocumentshouldbedirectedtotheusersnationalstandardsbody.Acompletelistingofthesebodiescanbefoundatwww.iso.org/members.htmLIntroductionThismethodprovidesameanstoevaluatethesoundabsorption
16、characteristicsofaroadsurfacewithoutdamagingthesurface.ThefieldofapplicationislimitedtolowabsorptionsurfacessuchasthoseinaccordancewithISO10844Kandsimilarsurfaces.Duetoairleakagethemethodisnotreliableifthemeasuredsoundabsorptioncoefficientexceeds0,15.SurfaceswithasoundabsorptioncoefficientofO1IOorbe
17、lowareconsideredreflective.Themethodinthisdocumentisbasedonpropagationofthetestsignalfromthesourcetotheroadsurfaceandbacktothereceiverthroughanimpedancetubewithadiameterof80mmto100mm.Thetubecoversanareaofapproximately0,0OSm2to0,008m2andafrequencyrange,inone-thirdoctavebands,from250Hzto1600Hzfora100m
18、mdiameter,orfrom250Hzto2000Hz,foran80mmdiametertube.ItusesthetestprocedureandsignalprocessingdescribedinISO10534-2,butbecauseofthedefinedfrequencyrangeofapplication,thedimensionsofthesystemarenotfreelyadjustable.TheessentialpartintheISO10534-2procedureisthedeterminationofthetransferfunctionbetweentw
19、omicrophonesatdifferentdistancesfromthesampleattheendofthetube.Inthiscaseofareflectingsampleatspecificfrequenciesdestructiveinterferences(nodes)willoccuratthemicrophonepositionsjeopardizingthecorrectdeterminationofthetransferfunctionbetweenthemicrophonepair.ThereforeinthisdocumenttheISO10534-2proced
20、ureisextendedwithapreferencefortransferfunctionHcalculatedastheratiooftheautospectrumS22atthelowestmicrophonepositionandthecrossspectrumS21andrequirementsontheresolution,thesamplefrequencyandtheblocklengthintheFFTanalysisaddedwitharequirementontheaveragenarrowbandcoherencewithinaone-thirdoctaveband.
21、Recommendationsforimprovementoftheaccuracybyalternativemicrophonearrangement,variationintransferfunctionandtypeofrandomnoisearepresentedinArmeXC.Thismethodiscomplementarytotheextendedsurfacemethod(ISO13472-lffl)thatcoversanareaofapproximately3m2andafrequencyrange,inone-thirdoctavebands,from250Hzto40
22、00Hz.Bothmethodsshouldgivesimilarresultsinthevalidfrequencyrange,buttheirfieldsofapplicationandthereforetheiraccuracywilldifferstrongly.ThemethoddescribedinISO13472-1haslimitedaccuracyatsmallsoundabsorptionvaluesandisthereforeunfittocheckcomplianceofsurfaceswiththerequirementsinISO10844orsimilarregu
23、lations,whilethemethoddescribedinthisstandardfailsathighersoundabsorptionvalues.Withintheirrangesofapplicabilitythemethodsareapplicablealsotoacousticmaterialsotherthanroadsurfaces.Themeasurementresultsbythismethodarecomparablewiththeresultsoftheimpedancetubemethod,performedonborecorestakenfromthesur
24、facesuchasISO10534-llISO10534-2andASTME1050-19m.Themeasurementresultsobtainedwiththismethodareingeneralnotcomparablewiththeresultsofthereverberationroommethod(ISO354t1l),becausethemethoddescribedinthisInternationalStandardusesaplaneprogressivewaveatnormalincidence,whilethereverberationroommethoduses
25、adiffusesoundfield.AcousticsMeasurementofsoundabsorptionpropertiesofroadsurfacesinsitu一Part2:Spotmethodforreflectivesurfaces1 ScopeThisdocumentspecifiesatestmethodformeasuringinsituthesoundabsorptioncoefficientofroadsurfacesfortheone-thirdoctavebandfrequenciesrangingfrom250Hzto1600Hzundernormalincid
26、enceconditions.Ifnecessaryforpracticalapplicationsthediameterofthetubecanbereducedto80mm.Thiswillincreasetheupperboundaryofthefrequencyrangeto2000Hzone-thirdoctaveband(see5.4)butreducestheareaundertest.Thetestmethodisintendedforthefollowingapplications: determinationofthesoundabsorptioncoefficient(a
27、nd,ifofinterest,alsothecomplexacousticalimpedance)ofsemi-densetodenseroadsurfaces; determinationofthesoundabsorptionpropertiesoftesttracksaccordingtoISO10844orothersimilarstandardsandtestsurfacesdefinedinnationalandinternationaltypeapprovalregulationsforroadvehiclesandtheirtyres; verificationoftheco
28、mplianceofthesoundabsorptioncoefficientofaroadsurfacewithdesignspecificationsorotherrequirements.2 NormativereferencesThefollowingdocumentsarereferredtointhetextinsuchawaythatsomeoralloftheircontentconstitutesrequirementsofthisdocument.Fordatedreferences,onlytheeditioncitedapplies.Forundatedreferenc
29、es,thelatesteditionofthereferenceddocument(includinganyamendments)applies.ISO10534-2:2023,AcousticsDeterminationofacousticpropertiesinimpedancetubesPart2:Two-microphonetechniquefornormalsoundabsorptioncoefficientandnormalsurfaceimpedanceISO/IECGuide98-3,UncertaintyofmeasurementPart3:Guidetotheexpres
30、sionofuncertaintyinmeasurement3 TermsanddefinitionsForthepurposesofthisdocument,thefollowingtermsanddefinitionsapply.ISOandIECmaintainterminologydatabasesforuseinstandardizationatthefollowingaddresses: ISOOnlinebrowsingplatform:availableathttps:WWW.iso.org/obp IECElectropedia:availableathttps:WWW.el
31、ectropedia.org/3.1frequencyrangefrequencyintervalinwhichmeasurementsarevalid,specifiedinone-thirdoctavebandsNote1toentry:SeeIEC61260-1.Note2toentry:Thefrequencyrangeisspecifiedinone-thirdoctavebands.Thismeansthatitslowestfrequencyisthelowerlimitofthelowerone-thirdoctavebandspecifiedanditshighestfreq
32、uencyistheupperlimitofthehighestone-thirdoctavebandspecified.Afrequencyrangespecifiedinone-thirdoctavebandsof250Hzto1600Hzcentrefrequencyimpliesafrequencyrangespecifiedinnarrowbandsof224Hzto1778Hz.3.2soundabsorptioncoefficientatnormalincidenceafractionofthesoundpowerofaplanewaveatnormalincidenceonth
33、etestobjectthatisabsorbedwithinthetestobject3.3soundpressurereflectionfactoratnormalincidencercomplexratioofthepressureofthereflectedwavetothepressureoftheincidentwaveatthesurfaceofthetestobjectforaplanewaveatnormalincidence3.4planeofreferencehypotheticalplanedefinedbytheundersideofthesealingdevicea
34、twhichthesoundpressurereflectionfactorandthenormalsurfaceimpedanceiscalculated3.5crossspectrumS12productp2Pi*determinedbythecomplexsoundpressurep1andp2attwomicrophonepositions1and2Note1toentry:*meansthecomplexconjugate.3.6autospectrumSllproductPlp1*determinedbythecomplexsoundpressurep1atamicrophonep
35、osition13.7transferfunction“12transferfunctionfrommicrophoneposition1to2,definedbythecomplexratiop2P=(221)Note1toentry:Thetransferfunctioncanalsobedefinedas(S/品)1utapplyingthatdefinitionwillleadaslightlyhighererrorwhenaveragedoverone-thirdoctavebands(seeReference7.3.8coherencefunctionY212coherencebe
36、tweenthesignalsatpositions1and2definedby212=5,122(5,11S,22)3.9normalsurfaceimpedanceZratioofthecomplexsoundpressuretothenormalcomponentofthecomplexsoundparticlevelocityinthereferenceplane4Principleofthemethod4.1 MeasurementprincipleThemeasurementprincipleisbasedonastandardimpedancetubeutilizingatwom
37、icrophonesarrangement(seeISO10534-2orASTME1050-19).Asoundsignalfromaloudspeakerlocatedatoneendpropagatesthroughthetube.Theopenendofthetubeisplacedonthesurfacetobemeasuredwithoutdistortionofthesurface.Thecomplexacoustictransferfunctionbetweentwomicrophonepositionsatdifferentheightsisdeterminedandused
38、tocomputethenormal-incidencesoundabsorptioncoefficientandrelatedquantities.Theprocedureenablesasingleskilledoperatortoperformsuchmeasurements.Theapplicationofthisprocedureonreflectivesurfacesexhibitsdestructiveinterferencesatthemicrophonepositionsatspecificfrequencies.Theoccurrenceofsuchdestructivei
39、nterferencesjeopardizestheaccuratecalculationofthetransferfunctionsignalledbythelossofcoherencebetweenthesignalsatbothmicrophonepositions.ThequalitylossduetointerferenceisaddressedinthisdocumentbydefiningaminimalresolutionintheFFTanalysisandaminimalnumberofaveragesovertheautospectraandcrossspectrath
40、atareusedtocalculatethetransferfunction.Thecoherenceinnarrowbandsoveraone-thirdoctavebandisusedasaqualitycriteria.AnneXCdescribesvariousmethodstoimprovethecoherence.Thereisnoneedforacalibrationformicrophonesasrequiredintypicalacousticmeasurements,butitdoesrequireaspecificverificationofthemicrophonep
41、air(三)foramplitudeandphaserelationshipbetweenmicrophonesandthedeterminationoftheinternalenergylossofthesystem.Theabsorptioncoefficientcoverstheone-thirdoctavebandfrequencyrangefrom250Hzto1600Hzincaseofa100mmtubediameterand250Hzto2000Hzincaseofan80mmtubediameter.81loudspeaker2 vibrationisolation3 mic
42、rophone1microphone2optionalmicrophone34 sealingbetweentubeandinsitudevice5 insitutestfixture6 sealingbetweenfixtureandsurfaceundertest(seeAnnexP)7 surfaceundertest8 soundsourceandsignalanalyserFigure1Configurationofthemeasuringdeviceandrelatedequipment1.2 SignalanalysisThesignalprocessingisdescribed
43、inISO10534-2andASTME1050-19S.ItconsistsofthemeasurementofthecomplextransferfunctionH12betweenthepair(三)ofmicrophones1and2inthepresenceofthesampleundertest.Thetransferfunctionisusedtocalculatethecomplexpressurereflectionfactorfromwhichtheacousticabsorptionisderived.TheproceduredescribedinISO10534-2an
44、dASTME1050-19includesasubproceduretocalibrateamplitudeandphaseresponseofthemicrophones.Inordertocontroltheerrorinthetestresult,primarilycausedbythenodes,itisalsonecessarytodeterminethecoherencebetweenthepair(三)ofmicrophones.Thenarrowbandcoherencevaluesareusedasqualitycriterium.Atleast80%ofallnarrowb
45、andfrequencieswithinaone-thirdoctavebandshallhaveacoherencevalueof80%orhigher.NOTEThiscriteriumiscomparabletothatstipulatedinEN15461.Incaseofapplicationofthreemicrophones(seeC.l)thecoherenceisalsousedtoselecttheoptimalmicrophonepairThesoundreflectionfactor,soundabsorptioncoefficientandacousticimpeda
46、nceisdeterminedaccordingtotheproceduredefinedinISO10534-2:2023,8.7to8.10.ForthisdocumentpreferenceisgiventoatransferfunctionHcalculatedastheratiooftheautospectrumS22atthelowestmicrophonepositionandthecrossspectrumS,21;H=S22/S21.AlthoughthenarrowbanderrorissimilartoacalculationbasedontheconventionalH
47、S1S11theone-thirdoctaveresultisaveragedovermorenarrowbandresults,thusreducingtheeffectofthenarrowbanderrorontheoverallone-thirdoctaveresult.1.3 InsitufixtureInthepresentmethodthetestsampleholderdescribedinISO10534-2isreplacedbyaninsitutestfixturethatenablesanairtightconnectionbetweentheinsideofthet
48、esttubeandthesurfaceoftheroadundertest.ThetesttubeandthefixturecaneitherbeintegratedintoasinglepieceoritcanbeconnectedbyafixingdeviceandanairtightsealsuchasarubberO-ring.Attheundersideoftheinsitutestfixture,sealingtotheroadsurfaceisobtainedbyaringofplasticdeformablematerialthatcreatesanairtightsealingofthefixturetothesurfacetextureoftheroad.Sealingisimprovedwithasmallgroovemadeint
