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ISO 10534-2-1998 声学阻抗管中吸声系数和比阻抗率的测量第2部分:传递函数法

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【英文标准名称】:Acoustics-Determinationofsoundabsorptioncoefficientandimpedanceinimpedancetubes-Part2:Transfer-functionmethod
【原文标准名称】:声学阻抗管中吸声系数和比阻抗率的测量第2部分:传递函数法
【标准号】:ISO10534-2-1998
【标准状态】:现行
【国别】:国际
【发布日期】:1998-11
【实施或试行日期】:
【发布单位】:国际标准化组织(IX-ISO)
【起草单位】:ISO/TC43
【标准类型】:()
【标准水平】:()
【中文主题词】:测定;声学;声音吸收;传输;声学测量;声学试验;吸声系数;建筑声学;吸声;声试验
【英文主题词】:Acousticabsorption;Acousticmeasurement;Acoustictesting;Acoustics;Buildingacoustics;Determination;Soundabsorption;Soundabsorptioncoefficient;Transmission
【摘要】:Thistestmethodcoverstheuseofanimpedancetube,twomicrophonelocationsandadigitalfrequencyanalysissystemforthedeterminationofthesoundabsorptioncoefficientofsoundabsorbersfornormalsoundincidence.Itcanalsobeappliedforthedeterminationoftheacousticalsurfaceimpedanceorsurfaceadmittanceofsoundabsorbingmaterials.Sincetheimpedanceratiosofasoundabsorptivematerialarerelatedtoitsphysicalproperties,suchasairflowresistance,porosity,elasticityanddensity,measurementsdescribedinthistestmethodareusefulinbasicresearchandproductdevelopment.ThetestmethodissimilartothetestmethodspecifiedinISO10534-1inthatitusesanimpedancetubewithasoundsourceconnectedtooneendandthetestsamplemountedinthetubeattheotherend.However,themeasurementtechniqueisdifferent.Inthistestmethod,planewavesaregeneratedinatubebyanoisesource,andthedecompositionoftheinterferencefieldisachievedbythemeasurementofacousticpressuresattwofixedlocationsusingwall-mountedmicrophonesoranin-tubetraversingmicrophone,andsubsequentcalculationofthecomplexacoustictransferfunction,thenormalincidenceabsorptionandtheimpedanceratiosoftheacousticmaterial.Thetestmethodisintendedtoprovideanalternative,andgenerallymuchfaster,measurementtechniquethanthatofISO10534-1.ComparedwiththemeasurementofthesoundabsorptioninareverberationroomaccordingtothemethodspecifiedinISO354,therearesomecharacteristicdifferences.Thereverberationroommethodwill(underidealconditions)determinethesoundabsorptioncoefficientfordiffusesoundincidence,andthemethodcanbeusedfortestingofmaterialswithpronouncedstructuresinthelateralandnormaldirections.However,thereverberationroommethodrequirestestspecimenswhichareratherlarge,soitisnotconvenientforresearchanddevelopmentwork,whereonlysmallsamplesoftheabsorberareavailable.Theimpedancetubemethodislimitedtoparametricstudiesatnormalincidencebutrequiressamplesofthetestobjectwhichareofthesamesizeasthecross-sectionoftheimpedancetube.Formaterialsthatarelocallyreacting,diffuseincidencesoundabsorptioncoefficientscanbeestimatedfrommeasurementresultsobtainedbytheimpedancetubemethod.Fortransformationofthetestresultsfromtheimpedancetubemethod(normalincidence)todiffusesoundincidence,seeannexF.
【中国标准分类号】:A42
【国际标准分类号】:17_140_01
【页数】:27P;A4
【正文语种】:英语


【英文标准名称】:DeterminationofpHofbutterserum
【原文标准名称】:奶油乳清中pH值的测定
【标准号】:DIN10349-1985
【标准状态】:作废
【国别】:德国
【发布日期】:1985-08
【实施或试行日期】:
【发布单位】:德国标准化学会(DE-DIN)
【起草单位】:
【标准类型】:()
【标准水平】:()
【中文主题词】:黄油;pH值测定;试验;定义;pH值;血清;乳制品;食品;食品检验
【英文主题词】:foodtesting;serums;butter;phmeasurement;definitions;foodproducts;dairyproducts;ph;testing
【摘要】:
【中国标准分类号】:X16
【国际标准分类号】:5315
【页数】:3P.;A4
【正文语种】:德语