【英文标准名称】:StandardPracticeforReducingSamplesofAggregatetoTestingSize
【原文标准名称】:将集料的现场试样减小到适于试验的标准实施规程
【标准号】:ASTMC702-1998(2003)
【标准状态】:现行
【国别】:
【发布日期】:1998
【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】:C09.20
【标准类型】:(Practice)
【标准水平】:()
【中文主题词】:试验;建筑;施工材料;尺寸;尺寸;集料;抽样方法;现场试验;减低
【英文主题词】:aggregate;aggregate&8212;coarse;aggregate&8212;fine;fieldtesting&8212;aggregate;sampling&8212;aggregates;samplereduction;specimenpreparation
【摘要】:Specificationsforaggregatesrequiresamplingportionsofthematerialfortesting.Otherfactorsbeingequal,largersampleswilltendtobemorerepresentativeofthetotalsupply.Thispracticeprovidesproceduresforreducingthelargesampleobtainedinthefieldorproducedinthelaboratorytoaconvenientsizeforconductinganumberofteststodescribethematerialandmeasureitsqualityinamannerthatthesmallertestsampleportionismostlikelytobearepresentationofthelargersample,andthusofthetotalsupply.Failuretocarefullyfollowtheproceduresinthispracticecouldresultinprovidinganonrepresentativesampletobeusedinsubsequenttesting.Theindividualtestmethodsprovideforminimumamountofmaterialtobetested.Undercertaincircumstances,reductioninsizeofthelargesamplepriortotestingisnotrecommended.Substantialdifferencesbetweentheselectedtestsamplessometimescannotbeavoided,asforexample,inthecaseofanaggregatehavingrelativelyfewlargesizeparticlesinthesample.Thelawsofchancedictatethatthesefewparticlesmaybeunequallydistributedamongthereducedsizetestsamples.Similarly,ifthetestsampleisbeingexaminedforcertaincontaminantsoccurringasafewdiscretefragmentsinonlysmallpercentages,cautionshouldbeusedininterpretingresultsfromthereducedsizetestsample.Chanceinclusionorexclusionofonlyoneortwoparticlesintheselectedtestsamplemayimportantlyinfluenceinterpretationofthecharacteristicsoftheoriginalsample.Inthesecases,theentireoriginalsampleshouldbetested.1.1Thispracticecoversthreemethodsforthereductionoflargesamplesofaggregatetotheappropriatesizefortestingemployingtechniquesthatareintendedtominimizevariationsinmeasuredcharacteristicsbetweenthetestsamplessoselectedandthelargesample.1.2ThevaluesstatedinSIunitsaretoberegardedasthestandard.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.
【中国标准分类号】:Q13
【国际标准分类号】:
【页数】:4P.;A4
【正文语种】:

标准名称：	DW-217电真空玻璃主要技术数据
英文名称：	Major technical data of vacuum glass Type DW-217
中标分类：	电子元器件与信息技术 >> 电子设备专用材料、零件、结构件 >> 电子技术专用材料
替代情况：	被SJ/T 10586.3-94代替
发布日期：
实施日期：	2004-03-01
首发日期：
作废日期：
出版日期：
页数：	1页

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