【英文标准名称】:Petroleumproducts-Determinationofacidnumber-Semi-microcolour-indicatortitrationmethod
【原文标准名称】:石油产品总酸值的测定半微量颜色指示剂滴定法
【标准号】:ISO7537-1997
【标准状态】:现行
【国别】:国际
【发布日期】:1997-07
【实施或试行日期】:
【发布单位】:国际标准化组织(IX-ISO)
【起草单位】:ISO/TC28
【标准类型】:()
【标准水平】:()
【中文主题词】:定义;测定;石油产品;酸值;含量测定;滴定法;容量分析;化学分析和试验
【英文主题词】:Acidnumber;Chemicalanalysisandtesting;Colourindicatortitration;Definitions;Determination;Determinationofcontent;Petroleumproducts;Titrationmethod;Volumetricanalysis
【摘要】:ThisInternationalStandardspecifiesasemi-microcolour-indicatormethodforthedeterminationofacidicconstituentsinneworusedpetroleumproductsandlubricantssolubleinmixturesoftolueneandpropan-2-ol,orcapableofexistingassuspensionsinsuchmixtures,andwherethesuspendedmaterialissufficientlydissociatedthatitsacidiccomponentscanbetitrated.ThemethodisespeciallyintendedforapplicationsinwhichtheamountofsampleavailabletobeanalysedistoosmalltoallowaccurateanalysisbyISO6619orISO6618.Itisapplicabletothedeterminationofacidshavingdissociationconstantsinwaterlargerthan10.Extremelyweakacidshavingdissociationconstantssmallerthan10donotinterfere.Saltstitrateiftheirhydrolysisconstantsarelargerthan10.NOTE1Thismethodmaybeusedtoindicaterelativechangesinacidnumberthatoccurinanoilduringuseunderoxidizingconditions.Althoughthetitrationismadeunderdefiniteequilibriumconditions,themethoddoesnotmeasureanabsoluteacidicpropertythatcanbeusedtopredictperformanceofanoilunderserviceconditions.Nogeneralrelationshipbetweenbearingcorrosionandacidnumberisknown.NOTE2SincethistestmethodrequiressubstantiallylesssamplethanISO6618orISO6619,itprovidesanadvantageousmeansofmonitoringanoxidationtestbychangesinacidnumberby:a)minimizingtestsampledepletionforacidnumberanalysesandthusminimizingthedisturbanceofthetest,andb)allowingadditionalacidnumberanalysestobemadewhilemaintainingthesametestsampledepletion,andthusprovidingadditionaldata.NOTE3Someoils,suchasmanycuttingoils,rustproofingoils,andsimilarcompoundedoils,orexcessivelydark-colouredoils,maybemoredifficulttoanalysebythismethodduetoobscurityofthecolour-indicatorend-point.TheseoilscanbeanalyzedbyISO6619providedsufficientsampleisavailable.However,thissituationismuchlesslikelyusingthisInternationalStandardthanusingISO6618,sincethesampleismorediluteduringthetitrationandtheend-pointcolourchangeismorestable.TheacidnumbersobtainedbythismethodmayormaynotbenumericallythesameasthoseobtainedbyISO6619,buttheyshouldbeofthesameorderofmagnitude.NOTE4TheresultsobtainedusingthismethodhavebeenfoundtobenumericallythesameasthoseobtainedusingISO6618,withintheprecisionofthetwomethods,forneworoxidizedlubricantsofthetypeprimarilyintendedforhydraulicorsteamturbinetypeservice.TheoxidizedlubricantswereobtainedusingISO4263.Thiscorrelationisshownbythecorrelationcoefficientr=0,989withslopes=1,017andintercepty=+0,029,calculatedusingtheacidnumbersobtainedusingbothtitrationmethodsforthesamplesusedfortheprecisionstatement(seeclause11).
【中国标准分类号】:E30
【国际标准分类号】:75_080
【页数】:9P;A4
【正文语种】:英语