Designation:D756–93StandardPracticeforDeterminationofWeightandShapeChangesofPlasticsUnderAcceleratedServiceConditions1ThisstandardisissuedunderthefixeddesignationD756;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(e)indicatesaneditorialchangesincethelastrevisionorreapproval.ThisstandardhasbeenapprovedforusebyagenciesoftheDepartmentofDefensetoreplaceMethod6011ofFederalTestMethodStandard406.ConsulttheDoDIndexofSpecificationsandStandardsforthespecificyearofissuewhichhasbeenadoptedbytheDepartmentofDefense.1.Scope1.1Thispracticecoversthedeterminationoftheweightandshapechangesoccurringinplasticsundervariousconditionsofuse,notwhereexposuretodirectsunlight,weathering,corro-siveatmospheres,orheataloneisinvolved,butwherechangesinatmospherictemperatureandhumidityareencountered.Thisembracestheinteriorofbuildings,andtheinterioroftransportfacilitiessuchasmotorvehicles,airplanecargospacesorwinginteriors,holdsofships,andrailroadcars.Proceduresareprovidedforexposingplasticstocombinationsofextremehumidityandtemperaturethatwillacceleratethechangestakingplaceinthematerialskeptinshelteredspacesbutsubjecttohumidityandtemperaturevariation(seeExplanatoryNote).1.2Seventestproceduresareprovidedwhichprescribeconditionsfordifferenttypesofexposure.Sixoftheproce-durescoverexposuresatgraduatedlevelsoftemperatureandextremesofhumidity;theseventhprescribesconditionsin-volvingalternateexposuretohighandlowtemperatures.Insofarasweightandshapechanges,embracedunderthegeneraltermofdimensionalstability,areconcerned,theseproceduresprovideamethodoftest.Furtheruseofanyoftheconditionssetupintheproceduresissuggested,suchasconditioningschedulespriortophysicaltestingoftheplasticeithertotestitattheparticularconditioninvolved,ortostudychangesresultingfromexposuretothatcondition.1.3ThevaluesstatedinSIunitsaretoberegardedasthestandard.Thevaluesgiveninparenthesesarefor...
