Designation:C177−13StandardTestMethodforSteady-StateHeatFluxMeasurementsandThermalTransmissionPropertiesbyMeansoftheGuarded-Hot-PlateApparatus1ThisstandardisissuedunderthefixeddesignationC177;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.ThisstandardhasbeenapprovedforusebyagenciesoftheU.S.DepartmentofDefense.1.Scope1.1Thistestmethodestablishesthecriteriaforthelabora-torymeasurementofthesteady-stateheatfluxthroughflat,homogeneousspecimen(s)whentheirsurfacesareincontactwithsolid,parallelboundariesheldatconstanttemperaturesusingtheguarded-hot-plateapparatus.1.2Thetestapparatusdesignedforthispurposeisknownasaguarded-hot-plateapparatusandisaprimary(orabsolute)method.Thistestmethodiscomparable,butnotidentical,toISO8302.1.3Thistestmethodsetsforththegeneraldesignrequire-mentsnecessarytoconstructandoperateasatisfactoryguarded-hot-plateapparatus.Itcoversawidevarietyofappa-ratusconstructions,testconditions,andoperatingconditions.Detaileddesignsconformingtothistestmethodarenotgivenbutmustbedevelopedwithintheconstraintsofthegeneralrequirements.Examplesofanalysistools,conceptsandproce-duresusedinthedesign,construction,calibrationandopera-tionofaguarded-hot-plateapparatusaregiveninRefs(1-41).21.4Thistestmethodencompassesboththesingle-sidedandthedouble-sidedmodesofmeasurement.Bothdistributedandlinesourceguardedheatingplatedesignsarepermitted.Theusershouldconsultthestandardpracticesonthesingle-sidedmodeofoperation,PracticeC1044,andonthelinesourceapparatus,PracticeC1043,forfurtherdetailsontheseheaterdesigns.1.5Theguarded-hot-plateapparatuscanbeoperatedwitheitherverticalorhorizontalheatflow.Theuseriscautionedhowever,sincethetestresultsfromthetwoorientationsmaybedifferentifconvectiveheatflowoccurswithinthespecimens.1.6Althoughnodefinitiveupperlimitcanbegivenforthemagnitudeof...
