Designation:C538−83(Reapproved2014)´1StandardTestMethodforColorRetentionofRed,Orange,andYellowPorcelainEnamels1ThisstandardisissuedunderthefixeddesignationC538;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.ε1NOTE—IntroductionwasaddedandminorunitsabbrevationcorrectionsmadeeditoriallyinJune2014.INTRODUCTIONThepurposeofthistestistodetectthosered,yellow,orange,andsomegreenporcelainenamelsthatarelikelytoexperienceappreciablecolorchangesuponexposuretoatmosphericcorrosion.1.Scope1.1Thistestmethod2coversonlyporcelainenamelscon-tainingthecadmium-sulfideorcadmiumsulfo-selenidetypesofpigments.Thepurposeofthetestistodetectthosered,yellow,orange,andsomegreenporcelainenamelsthatarelikelytoexperienceappreciablecolorchangesuponexposuretoatmosphericcorrosion.1.2Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.SummaryofTestMethod2.1Cupricsulfatesolutionisplacedonthesurfaceofappropriatesamplesandallowedtoremainfor20hundercontrolledillumination.Thesamplesarethenwashed,dried,andexaminedvisuallyforadarkeningofthecolorinthetestedarea.3.SignificanceandUse3.1Correlationbetweenresultsofthistestandoutdoorexposuretestsofporcelainenamelscoloredwithcadmiumsulfo-selenidepigmentshowsthatthecupricsulfatetestisaneffectiveindicatorofthetendencyforsuchcoatingstoexpe-rienceappreciablecolorchangesduringweathering.Thecu-pricsulfatetestisconsideredusefulforspecificationacceptance,qualitycontrol,andresearchanddevelopmentpurposes.4.Interferences4.1Insomecases,thetreatmentmaychangetheglossofthetestedarea.Anysuchglosschangeshallbedisregarded.5.ApparatusforControlofIllumination5.1Thelightsourceshallconsistof...
