Designation:E2985/E2985M−14StandardPracticeforDeterminationofMetalPurityBasedonElasticConstantMeasurementsDerivedfromResonantUltrasoundSpectroscopy1ThisstandardisissuedunderthefixeddesignationE2985/E2985M;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thispracticeisintendedforusewithresonantultra-soundspectrometerscapableofexciting,measuring,recordingandanalyzingmultiplewholebodymechanicalvibrationresonantfrequencieswithinpartsexhibitingacousticalringingintheacousticorultrasonic,orboth,resonantfrequencyranges.1.2ThispracticeusesResonantUltrasoundSpectroscopy(RUS)todistinguishconformingparts,asdeterminedfromqualifiedtrainingsets,fromthosecontainingsignificantanomaliesintheirelasticproperties.1.3ThebasicfunctionsofaRUSmonitoringsystemaretodetectandclassifyresonancephenomena.Solidstructureresonancesaregovernedbythepart’sdimensions,densityandelasticproperties.Whenamaterialsubstitutionoccursinapreciousmetal,thechosenmetalshavealmostidenticalden-sitiesandunchangeddimensions,leavingonlytheelasticpropertiestoaffecttheresonances.1.4Thispracticecanbeusedtoreplacedestructivemethods,whichdamagethetestobjectthroughdrillingormelting,orboth.1.5ThevaluesstatedineitherSIunitsorinch-poundunitsaretoberegardedseparatelyasstandard.Thevaluesstatedineachsystemmaynotbeexactequivalents;therefore,eachsystemshallbeusedindependentlyoftheother.Combiningvaluesfromthetwosystemsmayresultinnon-conformancewiththestandard.1.6Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2E543SpecificationforAgenciesPerformingNondestructiveTestingE1316TerminologyforNonde...
