Product Code:SAE AS4220
Title:Fitting, Elbow, 45 Degrees, Beam Seal Bulkhead
Issuing Committee:G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
Scope:No scope available.【英文标准名称】:StandardTestMethodforHygroscopicSorptionIsothermsofBuildingMaterials
【原文标准名称】:建筑材料的吸湿等热性的标准试验方法
【标准号】:ASTMC1498-2004a
【标准状态】:现行
【国别】:
【发布日期】:2004
【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】:C16.33
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:试验;建筑材料;复合材料;物理性能
【英文主题词】:hysteresis;moisturecontent;watervaporsorption
【摘要】:Thepurposeofthesetestsistoobtain,foraspecifiedtemperature,bymeansofaspecifiedlaboratoryprocedure,thevaluesoftheequilibriummoisturecontentatvariouslevelsofRH.Thesevaluesareusedeitherasmeanstocharacterizethematerialorasmaterialcharacteristicsneededasinputtoappropriatecomputermodelsthatcansimulatewettingordryingpotentialofindividualbuildingmaterialsormaterialassembliesunderspecifiedenvironmentalconditions.Aspecifiedvalueoftheequilibriummoisturecontentcanalsobeusedformaterialcharacterization.Ifthistypeofmaterialcharacterizationiscalledforinamaterialspecification(forexample,mineralorcellulosefiberinsulation),theequilibriumat95x00B1;3%RHshallbeused.Foreaseandrepeatabilityofmeasurements,themeasurementsforcharacterizationareperformedonadsorptionisotherms.Thoughdesorptionisthereverseofadsorption,mostporousmaterialsreachdifferentequilibriumlevelsduringthesetwoprocesses.Usually,theequilibriummoisturecontentonthedesorptionisothermishigherthanthatontheadsorptionisothermforthesamelevelofRH.1.1Thistestmethodspecifiesalaboratoryprocedureforthedeterminationofhygroscopicsorptionisothermsofanyconstructionmaterials.ThemethodwasoriginallydevelopedfortheASTMThermalInsulationcommittee.1.2Formaterialcharacterization,theprimaryemphasisisontheadsorptionisotherm(thatis,sorptionisothermthatdescribesthewettingprocessofthematerialfromtheoven-drycondition).1.3Determinationofdesorptionisotherm,(thatis,sorptionisothermthatdescribesthedryingprocessofamaterialfromthestateofabsolutesaturationwithwater)isperformedwheninformationondryingcharacteristicsofconstructionmaterialsisrequired.Typicallybothadsorptionanddesorptionisothermsarerequiredforthepurposeofhygrothermalmodels.1.4Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.
【中国标准分类号】:Q25
【国际标准分类号】:91_120_30
【页数】:4P.;A4
【正文语种】: