基本信息
| 标准名称： | pH(酸度) 计量器具检定系统 |
| 英文名称： | pH(acidity )Measuring Instrumetns |
| 中标分类： |
综合 >>
计量 >>
化学计量 |
| 发布部门： | 国家技术监督局 |
| 发布日期： | 1990-05-05 |
| 实施日期： | 1990-09-01 |
| 首发日期： | |
| 作废日期： | |
| 起草单位： | 国家标准物质研究中心 |
| 起草人： | 刘亚英 |
| 出版社： | 中国计量出版社 |
| 出版日期： | 1990-09-01 |
| 页数： | 8页 |
适用范围
本检定系统规定了借助一级pH标准物质、二级pH标准物质，由国家基准向各级工作计量器具传递pH量值的方法、程序，以及所用设备的名称、测量范围、不确定度等。
前言
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目录
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引用标准
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所属分类： 综合 计量 化学计量
【英文标准名称】:StandardTestMethodforTotalOxygenDemandinWater
【原文标准名称】:水中总氧要求的标准试验方法
【标准号】:ASTMD6238-1998(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】:D19.06
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:试验室分析;生产线检测;总氧要求;需氧量;鳕鱼
【英文主题词】:BOD;COD;laboratoryanalyzer;onlinemonitor;oxygendemand;totaloxygendemand;TOD
【摘要】:Themeasurementofoxygendemandparametersiscriticaltothecontrolofprocesswastewaters.Biochemicaloxygendemand(BOD)andchemicaloxygendemand(COD)analyzershavelongtimecyclesandinthecaseofCODanalyzersusecorrosivereagentswiththeinherentproblemofdisposal.Totaloxygendemandanalysisisfaster,approximately3min,andusesnoliquidreagentsinitsanalysis.TODcanbecorrelatedtobothCODandBOD,providingeffectiveon-linecontrol.TODoffersseveralfeatureswhichmakeitamoreattractivemeasurementthancarbonmonitoringusingTotalCarbon(TC)orTotalOrganicCarbon(TOC)analyzers.TODisunaffectedbythepresenceofinorganiccarbon.TODanalysiswillalsoindicatenoncarbonaceousmaterialsthatconsumeorcontributeoxygen.Forexample,theoxygendemandofammonia,sulfiteandsulfideswillbereflectedintheTODmeasurement.Also,sincetheactualmeasurementisoxygenconsumption,TODreflectstheoxidationstateofthechemicalcompound(thatis,ureaandformicacidhavethesamenumberofcarbonatoms,yetureahasfivetimestheoxygendemandofformicacid).1.1Thistestmethodcoversthedeterminationoftotaloxygendemandintherangefrom100to100000mg/L,inwaterandwastewaterincludingbrackishwatersandbrines(see6.5).Largerconcentrations,orsampleswithhighsuspendedsolids,orboth,maybedeterminedbysuitabledilutionofthesample.1.1.1Sincetheanalysisisbasedonthechangeinoxygenreadingofthecarriergascomparedtothatwhenasampleisintroduced(see4.1),themeasurementrangeisafunctionoftheamountofoxygeninthecarriergas.Thehigherthedesiredconcentrationrange,themoreoxygenrequiredinthecarriergas.Underrecommendedconditions,thecarriergasconcentrationshouldbebetweentwotofourtimesthemaximumdesiredoxygendemand.1.1.2Thelowermeasurementrangeislimitedbythestabilityofthebaselineoxygendetectoroutput.Thissignalisafunctionofthepermeationsystemtemperature,carriergasflowrate,oxygendetectortemperature,andreferencesensorvoltage.Combined,thesevariableslimittheminimumrecommendedrangeto2to100mg/L.1.1.3Theuppermeasurementrangeislimitedbythemaximumoxygenconcentrationinthecarriergas(100%).Withtherecommendedconditionsofcarriergasconcentrationbeingtwotofourtimesthemaximumoxygendemand,thislimitsthemaximumpossibleoxygendemandtobetween250000to500000mg/L.However,asapracticalapplicationtowateranalysis,thistestmethodwillconsideramaximumrangeof100000mg/L.1.2Thistestmethodisapplicabletoalloxygen-demandingsubstancesundertheconditionsofthetestcontainedinthesamplethatcanbeinjectedintothereactionzone.Theinjectoropeninglimitsthemaximumsizeofparticlesthatcanbeinjected.Ifoxygen-demandingsubstancesthatarewater-insolubleliquidsorsolidsarepresent,apreliminarytreatmentmaybedesired.ThesepretreatmentmethodsaredescribedinAnnexA2.1.3Thistestmethodisparticularlyusefulformeasuringoxygendemandincertainindustrialeffluentsandprocessstreams.Itsapplicationformonitoringsecondarysewageeffluentsisnotestablished.ItsuseforthemonitoringofnaturalwatersisgreatlylimitedbytheinterferencesdefinedinSection6.1.4Inadditiontolaboratoryanalysis,thistestmethodisapplicabletoon-streammonitoring.SampleconditioningtechniquesforsolidspretreatmentapplicationsarenotedinAnnexA2.1.5ThevaluesstatedinSIunitsaretoberegardedasthestandard.1.6Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicability......
【中国标准分类号】:Z16
【国际标准分类号】:13_060_50
【页数】:7P.;A4
【正文语种】: