Designation:D4575−09(Reapproved2019)StandardTestMethodsforRubberDeterioration—ReferenceandAlternativeMethod(s)forDeterminingOzoneLevelinLaboratoryTestChambers1ThisstandardisissuedunderthefixeddesignationD4575;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.INTRODUCTIONNumeroustechniquesexistfortheanalysisofgaseousozoneinozone-airmixturesusedforozonecracktestingofrubber.Theseincludewetchemicalprocedures,electrochemicalcells,UVabsorption,andchemiluminescencewithethylene.SeeRefs(1-4).2Wetchemicalmethods(theabsorptionofozoneinapotassiumiodidesolutionandtitrationoftheiodinereleasedwithsodiumthiosulfate)havebeenintraditionaluseintherubberindustry,buttheyarenotsuitableforcontinuousoperation,andinrecentyearstheyhavebeenshowntobesensitivetosmallvariationsintestproceduresandconcentrationandpurityofreagents.Interlaboratorytestshaveindicatedthatdifferentproceduresdonotgiveequivalentresults,andmostofthemdifferfromanabsoluteUVmethod.Frequently,wetchemicalmethodsyieldhigherozoneconcentrationsduetotheoxidizingcapacityofothercomponentsoftheozone-airmixture.Certainnonreferenceinstrumentalmethodsareamenabletoautomaticoperationandforthisreasontheyareincludedinthisstandard.TheymaybeusedforroutinetestingoncecalibratedagainstthereferenceUVmethod.UVabsorptionisadoptedasthereferencemethodagainstwhichtheothersshallbecalibrated.Itisanabsolutetestmethodandisincommonusebyenvironmentalprotectionagenciesforthedeterminationofpollutantozoneinair(see2.3).Althoughthesetestmethodsareconcernedwithozoneanalysis,italsodrawsattentiontotheinfluenceofatmosphericpressureontherateofcrackingofrubberatconstantozoneconcentrationasnormallyexpressedintermsofpartsbyvolume.AsdescribedinAppendixX2,thevariationinozoneresistancethatcanresultbetweenlaboratoriesoperatingatsignificantlydifferentatmosphericpressu...
