标准名称：	电视和调频广播发射天线馈线系统技术指标
中标分类：	通信、广播 >> 雷达、导航、遥控、遥测、天线 >> 天线及其馈线
发布日期：	1994-03-06
实施日期：	1994-06-01
首发日期：
作废日期：
出版日期：
页数：	5页

本标准适用于VHF、UHF电视和调频发射天线馈线系统。

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【英文标准名称】:StandardPracticeforConditioningPlasticsforTesting
【原文标准名称】:试验用塑料的调理的标准实施规程
【标准号】:ASTMD618-2005
【标准状态】:现行
【国别】:
【发布日期】:2005
【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】:D20.50
【标准类型】:(Practice)
【标准水平】:()
【中文主题词】:覆层;电气工程;电绝缘;绝缘;塑料;温湿度预调节;准备;工艺;试样制备;试验
【英文主题词】:conditioning;humidity;plastics;temperature;
【摘要】:Conditioningofspecimensmaybeundertaken:(1)forthepurposeofbringingthematerialintoequilibriumwithnormaloraverageroomconditions,(2)simplytoobtainreproducibleresults,regardlessofprevioushistoryofexposure,or(3)tosubjectthematerialtoabnormalconditionsoftemperatureorhumidityinordertopredictitsservicebehavior.Theconditioningproceduresprescribedinthispracticearedesignedtoobtainreproducibleresultsandmaygivephysicalvaluessomewhathigherorsomewhatlowerthanvaluesunderequilibriumatnormalconditions,dependingupontheparticularmaterialandtest.Toensuresubstantialequilibriumundernormalconditionsofhumidityandtemperature,however,mayrequirefrom20to100daysormoredependinguponthicknessandtypeofmaterialanditsprevioushistory.Consequently,conditioningforreproducibilitymustofnecessitybeusedforgeneralpurchasespecificationsandproductcontroltests.1.1Ingeneral,thephysicalandelectricalpropertiesofplasticsareinfluencedbytemperatureandrelativehumidityinamannerthatmateriallyaffectstestresults.Inorderthatreliablecomparisonsmaybemadeofdifferentmaterialsandbetweendifferentlaboratories,itisnecessarytostandardizethehumidityconditions,aswellasthetemperature,towhichspecimensofthesematerialsaresubjectedpriortoandduringtesting.Thispracticedefinesproceduresforconditioningplastics(althoughnotnecessarilytoequilibrium)priortotesting,andtheconditionsunderwhichtheyshallbetested.1.2Forsomematerials,theremaybeamaterialspecificationthatrequirestheuseofthispractice,butwithsomeproceduralmodifications.Thematerialspecificationtakesprecedenceoverthispractice.Refertothematerialspecificationbeforeusingthispractice.Table1inClassificationD4000liststheASTMmaterialspecificationsthatcurrentlyexist.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.Note1-ISO291isrelatedtothispractice;however,ISO291describesonlytwotemperatureandhumidityconditionsforconditioningortesting,orboth.
【中国标准分类号】:K15;G31
【国际标准分类号】:29_035_20
【页数】:4P.;A4
【正文语种】: