【英文标准名称】:StandardTestMethodforSteady-StateHeatFluxMeasurementsandThermalTransmissionPropertiesbyMeansoftheGuarded-Hot-PlateApparatus
【原文标准名称】:使用单面护热板设备测量稳态热通量和热传导特性的标准试验方法
【标准号】:ASTMC177-2010
【标准状态】:现行
【国别】:美国
【发布日期】:2010
【实施或试行日期】:
【发布单位】:美国材料与试验协会(US-ASTM)
【起草单位】:C16.30
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:
【英文主题词】:erroranalysis;guarded-hot-plate;heatflow;heatflux;steady-state;thermalconductivity;thermalresistance;thermaltransmission;thermalconductance;thermaltesting;Erroranalysis;Heatflux;Hotplate/boxmethods;Insulatingmaterials;T
【摘要】:Thistestmethodcoversthemeasurementofheatfluxandassociatedtestconditionsforflatspecimens.Theguarded-hot-plateapparatusisgenerallyusedtomeasuresteady-stateheatfluxthroughmaterialshavingax201C;lowx201D;thermalconductivityandcommonlydenotedasx201C;thermalinsulators.x201D;Acceptablemeasurementaccuracyrequiresaspecimengeometrywithalargeratioofareatothickness.Twospecimensareselectedwiththeirthickness,areas,anddensitiesasidenticalaspossible,andonespecimenisplacedoneachsideoftheguarded-hot-plate.Thefacesofthespecimensoppositetheguarded-hot-plateandprimaryguardareplacedincontactwiththesurfacesofthecoldsurfaceassemblies.Steady-stateheattransmissionthroughthermalinsulatorsisnoteasilymeasured,evenatroomtemperature.Thisisbecauseheatmaybetransmittedthroughaspecimenbyanyorallofthreeseparatemodesofheattransfer(radiation,conduction,andconvection);anyinhomogeneityoranisotropyinthespecimenmayrequirespecialexperimentalprecautionstomeasurethatflowofheat;hoursorevendaysmayberequiredtoachievethethermalsteady-state;noguardingsystemcanbeconstructedtoforcethemeteredheattopassonlythroughthetestareaofinsulationspecimenbeingmeasured;moisturecontentwithinthematerialmaycausetransientbehaviour;andphysicalorchemicalchangeinthematerialwithtimeorenvironmentalconditionmaypermanentlyalterthespecimen.Applicationofthistestmethodondifferenttestinsulationsrequiresthatthedesignermakechoicesinthedesignselectionofmaterialsofconstructionandmeasurementandcontrolsystems.Thustheremaybedifferentdesignsfortheguarded-hot-plateapparatuswhenusedatambientversuscryogenicorhightemperatures.Testthickness,temperaturerange,temperaturedifferencerange,ambientconditionsandothersystemparametersmustalsobeselectedduringthedesignphase.AnnexA1isreferencedtotheuser,whichaddressessuchissuesaslimitationsoftheapparatus,thicknessmeasurementconsiderationsandmeasurementuncertainties,allofwhichmustbeconsideredinthedesignandoperationoftheapparatus.Apparatusconstructedandoperatedinaccordancewiththistestmethodshouldbecapableofaccuratemeasurementsforitsdesignrangeofapplication.Sincethistestmethodisapplicabletoawiderangeofspecimencharacteristics,testconditions,andapparatusdesign,itisimpracticaltogiveanall-inclusivestatementofprecisionandbiasforthetestmethod.Analysisofthespecificapparatususedisrequiredtospecifyaprecisionandbiasforthereportedresults.Forthisreason,conformancewiththetestmethodrequiresthattheusermustestimateandreporttheuncertaintyoftheresultsunderthereportedtestconditions.Qualificationofanewapparatus.Whenanewormodifieddesignisdeveloped,testsshallbeconductedonatleasttwomaterialsofknownthermalstabilityandhavingverifiedorcalibratedpropertiestraceabletoanationalstandardslaboratory.Testsshallbeconductedforatleasttwosetsoftemperatureconditionsthatcovertheoperatingrangefortheapparatus.Ifthedifferencesbetweenthetestresultsandthenationalstandardslaboratorycharacterizationaredeterminedtobesignificant,thenthesourceoftheerrorshall,ifpossible,beidentified.Onlyaftersuccessfulcomparisonwiththecertifiedsamples,cantheapparatusclaimconformancewiththistestmethod.Itisrecommendedthatchecksbecontinuedonaperiodicbasistoconfirmcontinuedconformanceoftheapparatus.Thethermaltransmissionpropertiesofaspecimenofmaterial:mayvaryduetothecom..........
【中国标准分类号】:P31
【国际标准分类号】:17_200_10
【页数】:23P.;A4
【正文语种】:英语