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【英文标准名称】:StandardTestMethodforPrecipitatedSilica-SurfaceAreabyMultipointBETNitrogenAdsorption
【原文标准名称】:用多点布-埃-特氮气吸附法对沉积二氧化硅表面面积的标准测试方法
【标准号】:ASTMD1993-2003
【标准状态】:现行
【国别】:
【发布日期】:2003
【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】:D11.20
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:试验;硅酸盐
【英文主题词】:nitrogenadsorptionsurfacearea;precipitatedhydratedsilica;silicas;surfacearea;
【摘要】:Thistestmethodisusedtomeasurethesurfaceareaofprecipitated,hydratedsilicasthatisavailabletothenitrogenmoleculeusingthemultipoint(B.E.T.)method.Solidsadsorbnitrogenand,underspecificconditions,theadsorbedmoleculesapproachamonomolecularlayer.ThequantityinthishypotheticalmonomolecularlayeriscalculatedusingtheBETequation.Combiningthiswiththeareaoccupiedbythenitrogenmoleculeyieldsthetotalsurfaceareaofthesolid.Thistestmethodmeasurestheestimatedquantityofnitrogeninthemonomolecularlayerbyadsorptionatliquidnitrogentemperatureandatseveral(atleastfive)partialpressuresofnitrogen.Beforeasurfaceareadeterminationcanbemadeitisnecessarythatthesilicabestrippedofanymaterialwhichmayalreadybeadsorbedonthesurface.Thestrippingofadsorbedforeignmaterialeliminatestwopotentialerrors.Thefirsterrorisassociatedwiththeweightoftheforeignmaterial.Theseconderrorisassociatedwiththesurfaceareathattheforeignmaterialoccupies.1.1ThistestmethodcoversaprocedurewhichisusedtomeasurethesurfaceareaofprecipitatedhydratedsilicasbytheconventionalBrunauer,Emmett,andTeller(BET)theoryofmultilayergasadsorptionbehaviorusingmultipointdeterminations,similartothatusedforcarbonblackinTestMethodsD4820.Thistestmethodspecifiesthesamplepreparationandtreatment,instrumentcalibrations,requiredaccuracyandprecisionofexperimentaldata,andcalculationsofthesurfacearearesultsfromtheobtaineddata.1.2Thistestmethodisusedtodeterminethenitrogensurfaceareaofprecipitatedsilicaswithspecificsurfaceareasintherangeof1to50hm2/kg(10to500m2/g).1.3ThevaluesstatedinSIunitsaretoberegardedasthestandard.Thevaluesgiveninparenthesesareforinformationonly.1.4Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.Theminimumsafetyequipmentshouldincludeprotectivegloves,sturdyeyeandfaceprotection,andmeanstodealsafelywithaccidentalmercuryspills.
【中国标准分类号】:G53
【国际标准分类号】:71_060_20
【页数】:3P.;A4
【正文语种】:


【英文标准名称】:Sectionalspecification-Opticalcablestobeusedalongelectricalpowerlines(OCEPL);GermanversionEN187200:2001
【原文标准名称】:分规范.与电力传输线路共用的光缆(OCEPL)
【标准号】:DINEN187200-2002
【标准状态】:作废
【国别】:德国
【发布日期】:2002-02
【实施或试行日期】:2002-02-01
【发布单位】:德国标准化学会(DIN)
【起草单位】:
【标准类型】:()
【标准水平】:()
【中文主题词】:试验;梯度纤维;阻尼(波);质量保证;电缆;电缆;电导体;光波导;分规范;电子设备及元件;电力电缆;使用条件;装置;纤维光学;规范(验收);架空线;电缆结构;型式;尺寸选定;定义;作标记;护套电缆;电力导线;单模纤维;缩写
【英文主题词】:
【摘要】:
【中国标准分类号】:M33
【国际标准分类号】:33_180_10
【页数】:38P;A4
【正文语种】:德语