ASTM D5128-1990(2005) 在线测量低导电水pH的标准试验方法
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【英文标准名称】:StandardTestMethodforOn-LinepHMeasurementofWaterofLowConductivity
【原文标准名称】:在线测量低导电水pH的标准试验方法
【标准号】:ASTMD5128-1990(2005)
【标准状态】:现行
【国别】:
【发布日期】:1990
【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】:D19.03
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:水;pH值;试验方法
【英文主题词】:highpurity;lowconductivity;on-line;pH
【摘要】:pHmeasurementsaretypicallymadeinsolutionsthatcontainrelativelylargeamountsofacid,base,ordissolvedsalts.Undertheseconditions,pHdeterminationsmaybemadequicklyandprecisely.Continuouson-linepHmeasurementsinwatersamplesoflowconductivityaremoredifficult(4,5).Theselowionicstrengthsolutionsaresusceptibletocontaminationfromtheatmosphere,samplestreamhardware,andthepHelectrodes.Variationsintheconstituentconcentrationoflowconductivitywaterscauseliquidjunctionpotentialshifts(see3.1.1)resultinginpHmeasurementerrors.Theaggressivenatureandthehighelectricalresistanceofpureandultra-pure,lowconductivitywatersmaydegradethepHmeasurementelectrodesresultinginunstableanddriftingpHoutputsignals.Itisessentialtomakeon-linepHmeasurementsoflowconductivitywaterasaccuratelyaspossibletodeterminethepropercontrolofpHadjustmentchemicals,theeffectivenessofdemineralizerequipment,theeventandnatureofimpuritycontaminationofthewater,andinformationpertainingtotheoverallstatusofthepurewatersystem.1.1Thistestmethodcoversthepreciseon-linedeterminationofpHinwatersamplesofconductivitylowerthan100[mu]S/cm(seeTables1and2)overthepHrangeof3to11(seeFig.1),underfieldoperatingconditions,utilizingasealed,non-refillable,referenceelectrode.pHmeasurementsofwateroflowconductivityareproblematicalforconventionalpHelectrodes,methods,andrelatedmeasurementapparatus.1.2ThistestmethodincludestheproceduresandequipmentrequiredforthecontinuouspHmeasurementoflowconductivitywatersamplestreamsincludingtherequirementsforthecontrolofsamplestreampressure,flowrate,andtemperature.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.
【中国标准分类号】:Z16
【国际标准分类号】:71_040_50
【页数】:11P.;A4
【正文语种】:
【原文标准名称】:在线测量低导电水pH的标准试验方法
【标准号】:ASTMD5128-1990(2005)
【标准状态】:现行
【国别】:
【发布日期】:1990
【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】:D19.03
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:水;pH值;试验方法
【英文主题词】:highpurity;lowconductivity;on-line;pH
【摘要】:pHmeasurementsaretypicallymadeinsolutionsthatcontainrelativelylargeamountsofacid,base,ordissolvedsalts.Undertheseconditions,pHdeterminationsmaybemadequicklyandprecisely.Continuouson-linepHmeasurementsinwatersamplesoflowconductivityaremoredifficult(4,5).Theselowionicstrengthsolutionsaresusceptibletocontaminationfromtheatmosphere,samplestreamhardware,andthepHelectrodes.Variationsintheconstituentconcentrationoflowconductivitywaterscauseliquidjunctionpotentialshifts(see3.1.1)resultinginpHmeasurementerrors.Theaggressivenatureandthehighelectricalresistanceofpureandultra-pure,lowconductivitywatersmaydegradethepHmeasurementelectrodesresultinginunstableanddriftingpHoutputsignals.Itisessentialtomakeon-linepHmeasurementsoflowconductivitywaterasaccuratelyaspossibletodeterminethepropercontrolofpHadjustmentchemicals,theeffectivenessofdemineralizerequipment,theeventandnatureofimpuritycontaminationofthewater,andinformationpertainingtotheoverallstatusofthepurewatersystem.1.1Thistestmethodcoversthepreciseon-linedeterminationofpHinwatersamplesofconductivitylowerthan100[mu]S/cm(seeTables1and2)overthepHrangeof3to11(seeFig.1),underfieldoperatingconditions,utilizingasealed,non-refillable,referenceelectrode.pHmeasurementsofwateroflowconductivityareproblematicalforconventionalpHelectrodes,methods,andrelatedmeasurementapparatus.1.2ThistestmethodincludestheproceduresandequipmentrequiredforthecontinuouspHmeasurementoflowconductivitywatersamplestreamsincludingtherequirementsforthecontrolofsamplestreampressure,flowrate,andtemperature.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.
【中国标准分类号】:Z16
【国际标准分类号】:71_040_50
【页数】:11P.;A4
【正文语种】:
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