Designation:E1139/E1139M−17StandardPracticeforContinuousMonitoringofAcousticEmissionfromMetalPressureBoundaries1ThisstandardisissuedunderthefixeddesignationE1139/E1139M;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope*1.1Thispracticeprovidesguidelinesforcontinuousmoni-toringofacousticemission(AE)frommetalpressurebound-ariesinindustrialsystemsduringoperation.Examplesarepressurevessels,piping,andothersystemcomponentswhichservetocontainsystempressure.Pressureboundariesotherthanmetal,suchascomposites,arespecificallynotcoveredbythisdocument.1.2ThefunctionsofAEmonitoringaretodetect,locate,andcharacterizeAEsourcestoprovidedatatoevaluatetheirsignificancerelativetopressureboundaryintegrity.Thesesourcesarethoseactivatedduringsystemoperation,thatis,nospecialstimulusisappliedtoproduceAE.Othermethodsofnondestructivetesting(NDT)maybeused,whenthepressureboundaryisaccessible,tofurtherevaluateorsubstantiatethesignificanceofdetectedAEsources.1.3Units—ThevaluesstatedineitherSIunitsorinch-poundunitsaretoberegardedasstandard.Thevaluesstatedineachsystemmaynotbeexactequivalents;therefore,eachsystemshallbeusedindependentlyoftheother.Combiningvaluesfromthetwosystemsmayresultinnon-conformancewiththestandards.1.4Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.Forspecificprecautionarystatements,seeSection6.1.5Thisinternationalstandardwasdevelopedinaccor-dancewithinternationallyrecognizedprinciplesonstandard-izationestablishedintheDecisiononPrinciplesfortheDevelopmentofInternationalStandards,GuidesandRecom-mendationsissuedbytheWorldTradeOrganizationTechnicalBarrierstoTrade(TBT)Committee.2.R...
