NACE TM0497-2002 埋地或水下金属管道系统阴极保护准则的测量技术

StandardTestMethodMeasurementTechniquesRelatedtoCriteriaforCathodicProtectiononUndergroundorSubmergedMetallicPipingSystemsThisNACEInternationalstandardrepresentsaconsensusofthoseindividualmemberswhohavereviewedthisdocument,itsscope,andprovisions.Itsacceptancedoesnotinanyrespectprecludeanyone,whetherhehasadoptedthestandardornot,frommanufacturing,marketing,purchasing,orusingproducts,processes,orproceduresnotinconformancewiththisstandard.NothingcontainedinthisNACEInternationalstandardistobeconstruedasgrantinganyright,byimplicationorotherwise,tomanufacture,sell,oruseinconnectionwithanymethod,apparatus,orproductcoveredbyLettersPatent,orasindemnifyingorprotectinganyoneagainstliabilityforinfringementofLettersPatent.Thisstandardrepresentsminimumrequirementsandshouldinnowaybeinterpretedasarestrictionontheuseofbetterproceduresormaterials.Neitheristhisstandardintendedtoapplyinallcasesrelatingtothesubject.Unpredictablecircumstancesmaynegatetheusefulnessofthisstandardinspecificinstances.NACEInternationalassumesnoresponsibilityfortheinterpretationoruseofthisstandardbyotherpartiesandacceptsresponsibilityforonlythoseofficialNACEInternationalinterpretationsissuedbyNACEInternationalinaccordancewithitsgoverningproceduresandpolicieswhichprecludetheissuanceofinterpretationsbyindividualvolunteers.UsersofthisNACEInternationalstandardareresponsibleforreviewingappropriatehealth,safety,environmental,andregulatorydocumentsandfordeterminingtheirapplicabilityinrelationtothisstandardpriortoitsuse.ThisNACEInternationalstandardmaynotnecessarilyaddressallpotentialhealthandsafetyproblemsorenvironmentalhazardsassociatedwiththeuseofmaterials,equipment,and/oroperationsdetailedorreferredtowithinthisstandard.UsersofthisNACEInternationalstandardarealsoresponsibleforestablishingappropriatehealth,safety,andenvironmentalprotectionpractices,inconsultationwithappropriateregulatoryauthoritiesifnecessary,toachievecompliancewithanyexistingapplicableregulatoryrequirementspriortotheuseofthisstandard.CAUTIONARYNOTICE:NACEInternationalstandardsaresubjecttoperiodicreview,andmayberevisedorwithdrawnatanytimewithoutpriornotice.NACEInternationalrequiresthatactionbetakentoreaffirm,revise,orwithdrawthisstandardnolaterthanfiveyearsfromthedateofinitialpublication.Theuseriscautionedtoobtainthelatestedition.PurchasersofNACEInternationalstandardsmayreceivecurrentinformationonallstandardsandotherNACEInternationalpublicationsbycontactingtheNACEInternationalMembershipServicesDepartment,1440SouthCreekDrive,Houston,Texas77084-4906(telephone[phone]).Reaffirmed2002-04-11Approved1997-12-22NACEInternational1440SouthCreekDriveHouston,Texas77084-4906+1281/228-6200ISBN1-57590-047-5©2002,NACEInternationalNACEStandardTM0497-2002ItemNo.21231TM0497-2002NACEInternationali________________________________________________________________________ForewordThisNACEInternationalstandardtestmethodprovidesdescriptionsofthemeasurementtechniquesandcautionarymeasuresmostcommonlyusedonundergroundpipingtodeterminewhetheraspecificcriterionhasbeencompliedwithatatestsite.Thistestmethodincludesonlythosemeasurementtechniquesthatrelatetothecriteriaorspecialconditions,suchasanetprotectivecurrent,containedinNACEStandardRP0169.1Thistestmethodisintendedforusebycorrosioncontrolpersonnelconcernedwiththecorrosionofburiedundergroundorsubmergedpipingsystems,includingoil,gas,water,andsimilarstructures.Themeasurementtechniquesdescribedrequirethatthemeasurementsbemadeinthefield.Becausethemeasurementsareobtainedunderwidelyvaryingcircumstancesoffieldconditionsandpipelinedesign,thisstandardisnotasprescriptiveasthoseNACEstandardtestmethodsthatuselaboratorymeasurements.Instead,thisstandardgivestheuserlatitudetomaketestingdecisionsinthefieldbasedonthetechnicalfactsavailable.Thisstandardcontainsinstrumentationandgeneralmeasurementguidelines.Itincludesmethodsforvoltagedropconsiderationswhenmakingpipe-to-electrolytepotentialmeasurementsandprovidesguidancetopreventincorrectdatafrombeingcollectedandused.Themeasurementtechniquesprovidedinthisstandardwerecompiledfrominformationsubmittedbycommitteemembersandotherswithexpertiseonthesubject.Variationsorothertechniquesnotincludedmaybeequallyeffective.Thecomplexityanddiversityofenvironmentalconditionsmayrequiretheuseofothertechniques.AppendixAcontainsinformationonthecommontypes,use,andmaintenanceofreferenceelectrodes.AppendixBcontainsinformationforthenetprotectivecurrenttechnique,which,whilenotacriterion,isausefultechniquetoreducecorrosion.AppendixCcontainsinformationregardingtheuseofcouponstoevaluatecathodicprotection.Whilesomeengineersusethesetechniques,theyarenotuniversallyacceptedpractices.However,thereisongoingresearchintotheiruse.ThetestmethodsinthisstandardwereoriginallypreparedbyNACETaskGroupT-10A-3onTestMethodsandMeasurementTechniquesRelatedtoCathodicProtectionCriteria,acomponentofUnitCommitteeT-10AonCathodicProtection.ItwasreviewedbyTaskGroup020andreaffirmedin2002bySpecificTechnologyGroup(STG)35onPipelines,Tanks,andWellCasings.ThisstandardisissuedbyNACEundertheauspiceso