【英文标准名称】:StandardTestMethodforWaterVaporTransmissionRateofSheetMaterialsUsingDynamicRelativeHumidityMeasurement
【原文标准名称】:用动态相对湿度测量法测定薄板材料中水蒸气透过率的标准试验方法
【标准号】:ASTME398-2003
【标准状态】:现行
【国别】:
【发布日期】:2003
【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】:F02.10
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:相对的;水蒸气透过性;薄板材;湿度测量;动态的;水蒸气
【英文主题词】:dynamicmeasurement;flexiblebarriermaterials;relativehumidity;sheetmaterial;watervaportransmission
【摘要】:Nosinglesetoftestconditionscanrepresentallclimaticanduseconditions,sothisWVTRtestmethodservesmoretocomparedifferentmaterialsatastatedsetofconditionsthantopredicttheiractualperformanceinthefieldunderanyconditions.Thewatervaportransmissionrate,underknownandcarefullycontrolledconditions,maybeusedtoevaluatethevaporbarrierqualitiesofasheet.Directcorrelationofvaluesobtainedunderdifferentconditionsoftesttemperatureandrelativehumiditywillbevalidprovidedthebarriermaterialundertestdoesnotundergochangesinsolidstate(suchasacrystallinetransitionormeltingpoint)atorbetweentheconditionsoftest.1.1Thistestmethodcoversdynamicevaluationoftherateoftransferofwatervaporthroughaflexiblebarriermaterialandallowsconversiontothegenerallyrecognizedunitsofwatervaportransmission(WVT)asobtainedbyvariousothertestmethodsincludingthegravimetricmethoddescribedinTestMethodsE96.1.2LimitationsThistestmethodislimitedtoflexiblebarriersheetmaterialscomposedofeithercompletelyhydrophobicmaterials,orcombinationsofhydrophobicandhydrophilicmaterialshavingatleastonesurfacethatishydrophobic.1.3Theminimumtestvalueobtainedbythistestmethodislimitedbytheleakageofwatervaporpasttheclampingsealsofthetestinstrument.Areasonablevaluemaybeapproximately0.01g/24hm2foranyWVTRmethodincludingthedesiccantprocedureofTestMethodsE96at37.8C(100F),and90%relativehumidity.Thislimitcanbecheckedforeachinstrumentwithanimperviousspecimensuchasaluminumfoil.Calibrationprocedurescancompensatefortheleakagerateifsostated.1.4Thistestmethodisnotsuitableforrefereetestingatthistime,butissuitableforcontroltestingandmaterialcomparison.1.5ThevaluesstatedinSIunitsaretoberegardedasstandard.Thevaluesgivesinparenthesesareprovidedforinformationpurposesonly.1.6SeveralotherASTMtestmethodsareavailabletotestasimilarproperty.Thistestmethodisuniqueinthatitcloselyduplicatestypicalproductstoragewhereatransferofmoisturefromapackageintotheenvironmentisallowedtoproceedwithoutconstantlysweepingtheenvironmentalsidewithdrygas.MethodswithconstantlysweptdrysidesincludeTestMethodsF1249,ASTMF372,andASTMF1770.1.7Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.
【中国标准分类号】:A80
【国际标准分类号】:
【页数】:4P.;A4
【正文语种】: