Designation:D662−93(Reapproved2019)StandardTestMethodforEvaluatingDegreeofErosionofExteriorPaints1ThisstandardisissuedunderthefixeddesignationD662;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.ThisstandardhasbeenapprovedforusebyagenciesoftheU.S.DepartmentofDefense.1.Scope1.1Thistestmethodcoverstheevaluationofthedegreeoferosionofexteriorpaintsbycomparisonwithphotographicstandards.1.2Thisinternationalstandardwasdevelopedinaccor-dancewithinternationallyrecognizedprinciplesonstandard-izationestablishedintheDecisiononPrinciplesfortheDevelopmentofInternationalStandards,GuidesandRecom-mendationsissuedbytheWorldTradeOrganizationTechnicalBarrierstoTrade(TBT)Committee.2.ReferencedDocuments2.1ASTMStandards:2D4214TestMethodsforEvaluatingtheDegreeofChalkingofExteriorPaintFilms2.2OtherStandards:PictorialStandardsofCoatingDefectsHandbook33.Terminology3.1DefinitionsofTermsSpecifictoThisStandard:3.1.1erosion,n—thatphenomenonmanifestedinpaintfilmsbythewearingawayofthefinishtoexposethesubstrateorundercoat.3.1.1.1Discussion—Thedegreeoffailureisdependentontheamountofsubstrateorundercoatvisible.Erosionoccursastheresultofchalking.(SeeTestMethodsD4214forevaluationofchalking.)4.SignificanceandUse4.1Erosionfailureofpaintfilmscanoccurinuse.Thistestmethodprovidesameanofevaluatingthedegreeoffailurebycomparingtopictorialstandards.5.TypesofErosion5.1Onlyonetypeoferosionisrecognized,asdefinedinSection3.6.UseofPhotographicReferenceStandards6.1ThephotographicreferencestandardsthatarepartofthistestmethodandareprovidedinthePictorialStandardsofCoatingDefectsHandbookarerepresentativeofthedegreeoferosionofexteriorpaintfilms.Fig.1isforillustrationpurposesonlyandshouldnotbeusedforevaluation.6.2Theuseofthephotographicreferencestandards3illus-tratedinFig.1requiresthefollowingprecautions:6.2.1Car...
