Designation:D648−18StandardTestMethodforDeflectionTemperatureofPlasticsUnderFlexuralLoadintheEdgewisePosition1ThisstandardisissuedunderthefixeddesignationD648;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.ThisstandardhasbeenapprovedforusebyagenciesoftheU.S.DepartmentofDefense.1.Scope*1.1Thistestmethodcoversthedeterminationofthetem-peratureatwhichanarbitrarydeformationoccurswhenspeci-mensaresubjectedtoanarbitrarysetoftestingconditions.1.2Thistestmethodappliestomoldedandsheetmaterialsavailableinthicknessesof3mm(1⁄8in.)orgreaterandwhicharerigidorsemirigidatnormaltemperature.NOTE1—Sheetstocklessthan3mm(0.125in.)butmorethan1mm(0.040in.)inthicknessmaybetestedbyuseofacompositesamplehavingaminimumthicknessof3mm.Thelaminaemustbeofuniformstressdistribution.Onetypeofcompositespecimenhasbeenpreparedbycementingtheendsofthelaminaetogetherandthensmoothingtheedgeswithsandpaper.Thedirectionofloadingshallbeperpendiculartotheedgesoftheindividuallaminae.1.3ThevaluesstatedinSIunitsaretoberegardedasstandard.Thevaluesgiveninparenthesesareforinformationonly.1.4Someoldermachinesstillusemercury-in-glassther-mometers.(Warning—Mercuryhasbeendesignatedbymanyregulatoryagenciesasahazardousmaterialthatcancauseseriousmedicalissues.Mercury,oritsvapor,hasbeendemonstratedtobehazardoustohealthandcorrosivetomaterials.Cautionshouldbetakenwhenhandlingmercuryandmercurycontainingproducts.SeetheapplicableproductSafetyDataSheet(SDS)foradditionalinformation.Usersshouldbeawarethatsellingmercuryand/ormercurycontain-ingproductsintoyourstateorcountrymaybeprohibitedbylaw.1.5Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafety,health,andenvironmentalpracticesanddeter-minetheapplicabilityofregulator...
