【英文标准名称】:StandardTestMethodforVolatilityRatebyThermogravimetry
【原文标准名称】:用热重分析法测定挥发速度的标准试验方法
【标准号】:ASTME2008-2007
【标准状态】:现行
【国别】:
【发布日期】:2007
【实施或试行日期】:
【发布单位】:美国材料与试验协会(ASTM)
【起草单位】:E37.01
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:质量损失;试验方法;热重分析法;挥发性
【英文主题词】:massloss;thermogravimetricanalysis(TGA);thermogravimetry(TG);volatility;volatilityrate;
【摘要】:Volatilityofamaterialisnotanequilibriumthermodynamicpropertybutisacharacteristicofamaterialrelatedtoathermodynamicpropertythatisvaporpressure.Itisinfluencedbysuchfactorsassurfacearea,temperature,particlesize,andpurgegasflowrate;thatis,itisdiffusioncontrolled.Theextentofcontainmentachievedforspecimensinthistestmethodbymeansofapinholeopeningbetween0.33to0.38mmallowsformeasurementcircumstancesthatarerelativelyinsensitivetoexperimentalvariablesotherthantemperature.Decreasingtheextentofcontainmentbyuseofpinholeslargerthan0.38mmwillincreasethemagnitudeoftheobservedrateofmasslossbutwillalsoreducethemeasurementprecisionbyincreasingthesensitivitytovariationsinotherexperimentalvariables.Resultsobtainedbythistestmethodarenotstrictlyequivalenttothoseexperiencedinprocessingorhandlingconditionsbutmaybeusedtorankmaterialsfortheirvolatilityinsuchcircumstances.Therefore,thevolatilityratesdeterminedbythistestmethodshouldbeconsideredasindexvaluesonly.Thevolatilityratemaybeusedtoestimatesuchquantifiablevaluesasdryingintervalortheextentofvolatilereleasefromaprocess.1.1Thistestmethodcoversproceduresforassessingthevolatilityofsolidsandliquidsatgiventemperaturesusingthermogravimetryunderprescribedexperimentalconditions.Resultsofthistestmethodareobtainedasvolatilityratesexpressedasmassperunittime.Rates5g/minareachievablewiththistestmethod.1.2Temperaturestypicalforthistestmethodarewithintherangefrom25176;Cto500176;C.Thistemperaturerangemaydifferdependingupontheinstrumentationused.1.3Thistestmethodisintendedtoprovideavalueforthevolatilityrateofasampleusingathermogravimetricanalysismeasurementonasinglerepresentativespecimen.Itistheresponsibilityoftheuserofthistestmethodtodeterminetheneedforandthenumberofrepetitivemeasurementsonfreshspecimensnecessarytosatisfyenduserequirements.1.4Computer-orelectronic-basedinstruments,techniques,ordatatreatmentequivalenttothistestmethodmayalsobeused.Note1Usersofthistestmethodareexpresslyadvisedthatallsuchinstrumentsortechniquesmaynotbeequivalent.Itistheresponsibilityoftheuserofthistestmethodtodeterminethenecessaryequivalencypriortouse.1.5SIunitsarethestandard.1.6ThereisnoISOmethodequivalenttothisstandard.Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthistestmethodtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.
【中国标准分类号】:A42
【国际标准分类号】:71_040_50
【页数】:6P.;A4
【正文语种】: