ASTM E1995-2008 在单个闭室中利用带水平试样的锥形辐射源测量烟雾昏暗度的标准试验方法

作者:标准资料网 时间:2024-05-16 19:55:12  浏览:8950   来源:标准资料网

【英文标准名称】:StandardTestMethodforMeasurementofSmokeObscurationUsingaConicalRadiantSourceinaSingleClosedChamber,WiththeTestSpecimenOrientedHorizontally
【原文标准名称】:在单个闭室中利用带水平试样的锥形辐射源测量烟雾昏暗度的标准试验方法
【标准号】:ASTME1995-2008
【标准状态】:现行
【国别】:美国
【发布日期】:2008
【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】:E05.21
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:
【英文主题词】:coneheater;fire;fire-test-responsecharacteristic;opticaldensity;smoke;smokeobscuration;Calibration--air/atmosphericanalysisinstruments;Calibration--temperatureanalysisinstrumentation;Closedchambertesting;Conicalradiantheater;Fir
【摘要】:Thistestmethodprovidesameansfordeterminingthespecificopticaldensityofthesmokegeneratedbyspecimensofmaterials,products,orassembliesunderthespecifiedexposureconditions.Valuesdeterminedbythistestarespecifictothespecimenintheformandthicknesstestedandarenotinherentfundamentalpropertiesofthematerial,product,orassemblytested.Thistestmethodusesaphotometricscaletomeasuresmokeobscuration,whichissimilartotheopticaldensityscaleforhumanvision.Thetestmethoddoesnotmeasurephysiologicalaspectsassociatedwithvision.Atthepresenttimenobasisexistsforpredictingthesmokeobscurationtobegeneratedbythespecimensuponexposuretoheatorflameunderanyfireconditionsotherthanthosespecified.Moreover,aswithmanysmokeobscurationtestmethods,thecorrelationwithmeasurementsbyothertestmethodshasnotbeenestablished.Thecurrentsmokedensitychambertest,TestMethodE662,isusedbyspecifiersoffloorcoveringsandintherailtransportationindustries.Themeasurementofsmokeobscurationisimportanttotheresearcherandtheproductdevelopmentscientist.Thistestmethod,whichincorporatesimprovementsoverTestMethodE662,alsowillincreasetheusefulnessofsmokeobscurationmeasurementstothespecifierandtoproductmanufacturers.ThefollowingareimprovementsofferedbythistestmethodoverTestMethodE662:thehorizontalspecimenorientationsolvestheproblemofmeltingandflamingdripsfromverticallyorientedspecimens;theconicalheatsourceprovidesamoreuniformheatinput;theheatinputcanbevariedoverarangeofupto50kW/m2,ratherthanhavingafixedvalueof25kW/m2;and,the(optional)loadcellpermitscalculationstobemadeofmassopticaldensity,whichassociatesthesmokeobscurationfire-test-responsecharacteristicmeasuredwiththemassloss.Limitations:Thefollowingbehaviorduringatestrendersthattestinvalid:aspecimenbeingdisplacedfromthezoneofcontrolledirradiancesoastotouchthepilotburnerorthepilotflame;extinctionofthepilotflame(evenforashortperiodoftime)intheflamingmode;moltenmaterialoverflowingthespecimenholder;or,self-ignitioninthenonflamingmode.Asisusualinsmall-scaletestmethods,resultsobtainedfromthistestmethodhaveproventobeaffectedbyvariationsinspecimengeometry,surfaceorientation,thickness(eitheroverallorindividuallayer),mass,andcomposition.Theresultsofthetestapplyonlytothethicknessofthespecimenastested.Nosimplemathematicalformulaexiststocalculatethespecificopticaldensityofaspecimenataspecimenthicknessdifferentfromthethicknessatwhichitwastested.Theliteraturecontainssomeinformationonarelationshipbetweenopticaldensityandspecimenthickness[1].Resultsobtainedfromthistestmethodareaffectedbyvariationsinthepositionofthespecimenandradiometerrelativetotheradiantheatsource,sincetherelativepositioningaffectstheradiantheatflux(seealsoAppendixX2).Thetestresultshaveprovensensitivetoexcessiveaccumulationsofresidueinthechamber,whichserveasadditionalinsulators,tendingtoreducenormallyexpectedcondensationoftheaerosol,therebyraisingthemeasuredspecificopticaldensity(see5.5.8.3and11.1.2).Themeasurementsobtainedhavealsoprovensensitivetodifferencesinconditioning(seeSection10).Manymaterials,products,orassemblies,suchassomecarpeting,wood,plastics,ortextiles,requirelongperiodstoattainequilibrium(constantweight)eveninaforced-draftconditioningchamber.Thissensitivityreflectstheinherentnatu......
【中国标准分类号】:C80
【国际标准分类号】:13_220_40
【页数】:24P.;A4
【正文语种】:英语