基本信息
| 标准名称： | 液压式压力试验机 产品质量分等 |
| 替代情况： | JB/T57081-94 |
| 发布部门： | 全国试验机标委会 |
| 发布日期： | 1999-12-30 |
| 实施日期： | 2000-06-01 |
| 首发日期： | 1900-01-01 |
| 作废日期： | 1900-01-01 |
| 出版日期： | 1900-01-01 |
适用范围
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前言
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引用标准
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所属分类： 仪器 仪表 其他仪器仪表 气象仪器
【英文标准名称】:StandardTestMethodforCharacterizingtheEffectofExposuretoEnvironmentalCyclingonThermalPerformanceofInsulationProducts
【原文标准名称】:暴露于环境循环对绝缘产品热性能特征影响的标准试验方法
【标准号】:ASTMC1512-2007
【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(US-ASTM)
【起草单位】:C16.33
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:环境测试;曝露;绝缘;污染控制;试验方法;热分析;绝热材料;隔热;热应力
【英文主题词】:environmentalcycling;thermalinsulation
【摘要】:Exposingaspecimentoconditionsofone-directionalenvironmentalcyclingcanincreaseitsmoisturecontentuntiladecreaseinmaterialpropertiesoccurs(ataspecificnumberofcycles).Suchatestcouldbeinappropriateduetothenumberofcyclesrequiredtocauseadecreaseinmaterialpropertiessinceproductperformanceissuesoftenariseonlyaftermanyyearsofexposure.Theuseofapreconditioningprocedureisnotintendedtoduplicateexpectedfieldperformance.Ratherthepurposeistoincreasethemoisturecontentoftestmaterialspriortosubjectingtothemtoenvironmentalcycling.Themostimportantaspectofthepreconditioningprocedureisnon-uniformmoisturedistributioninthespecimen.Theheatflowisonedirectionalcausingmoistureflowtowardsthecoldsideresultinginzonesofdrymaterialonthewarmsideandhighmoisturecontentonthecoldside.(Whetherthehighmoisturecontentzoneislocatedrightatthecoldsurfaceofthespecimenoratsomedistancefromthissurfacedependsupontemperatureoscillationandabilityofthecoldsurfacetodryoutwards).Becausethepreconditioningprocedureinvolvesthermalgradient,thispreconditioningprocedureresultsinadistributionofmoisturecontentthatmayoccurunderfieldexposureconditions.However,theresultingmoisturecontentmaydiffersignificantlyfromthatwhichmaybedemonstratedintypicalproductapplications.Thepreconditioningresultsinaccumulationofmoistureinthethermalinsulationresultingfromthesimultaneousexposuretoadifferenceintemperatureandwatervaporpressure.Thistestmethodisnotintendedtoduplicatefieldexposure.Itisintendedtoprovidecomparativeratings.Asexcessiveaccumulationofmoistureinaconstructionsystemmayadverselyaffectitsperformance,thedesignershouldconsiderthepotentialformoistureaccumulationandthepossibleeffectsofthismoistureonthesystemperformance.1.1Thistestmethodisapplicabletopreformedorfieldmanufacturedthermalinsulationproducts,suchasboardstockfoams,rigidfibrousandcompositematerialsmanufacturedwithorwithoutprotectivefacings.SeeNote0Thistestmethodisnotapplicabletohightemperature,reflectiveorloosefillinsulation.Note0Iftheproductismanufacturedwithafacer,testproductwithfacerinplace.1.2Thistestmethodinvolvestwostages:preconditioningandenvironmentalcycling.Duringthefirststage,25mm(1in.)thickspecimensareusedtoseparatetwoenvironments.Eachoftheseenvironmentshasaconstantbutdifferenttemperatureandhumiditylevel.Duringtheenvironmentalcyclingstage,specimensalsodividetwoenvironmentsnamelyconstantroomtemperature/humidityononesideandcyclingtemperature/ambientrelativehumidityontheotherside.1.3Thistestmethodmeasurestheabilityoftheproducttomaintainthermalperformanceandcriticalphysicalattributesafterbeingsubjectedtostandardizedexposureconditions.Acomparisonismadebetweenmaterialpropertiesforreferencespecimensstoredinthelaboratoryforthetestperiodandspecimenssubjectedtothetwo-stagetestmethod.Toeliminatetheeffectofmoisturefromthecomparison,thematerialpropertiesofthelattertestspecimensaredeterminedaftertheyhavebeendriedtoconstantweight.Theaveragevaluedeterminedforeachofthetwosetsofspecimensisusedforcomparison.1.4Differentpropertiescanbemeasuredtoassesstheeffectofenvironmentalfactorsonthermalinsulation.Thistestmethodrequiresthatthermalresistancebedeterminedbaseduponanaverageforthreespecimensmeasuredaftercompletingthetest.Secondaryelementsofthistestmethodincludevisualobservationssuchascracking,delaminationorothersurfacedefects,aswellasthechangeinmoisturecontentaftereachofthetwostagesofexposur......
【中国标准分类号】:K15
【国际标准分类号】:13_020_60
【页数】:5P.;A4
【正文语种】: