ASTM-D-1518-1985-E1998-R2003

Designation:D1518–85(Reapproved2003)StandardTestMethodforThermalTransmittanceofTextileMaterials1ThisstandardisissuedunderthefixeddesignationD1518;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(e)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodcoversthedeterminationoftheoverallthermaltransmissioncoefficientsduetothecombinedactionofconduction,convection,andradiationfordryspecimensoftextilefabrics,battings,andothermaterialswithinthelimitsspecifiedin1.2.Itmeasuresthetimerateofheattransferfromawarm,dry,constant-temperature,horizontalflat-plateupthroughalayerofthetestmaterialtoarelativelycalm,coolatmosphere.1.2Forpracticalpurposes,thistestmethodislimitedtodeterminationsonspecimensoffabrics,layeredfabricassem-blies,andbattingshavingthermaltransmittances(U2,asdefinedin3.1.2)withinarangeof0.7to14W/m2·Kandthicknessesnotinexcessof50mm.1.3Thecoefficientsobtainedapplystrictlyonlytotheparticularspecimenstestedandforthespecifiedthermalandenvironmentalconditionsofeachtest.Thistestmethodgivesvaluesthatarevalidforcomparisonunderthesameconditionsoftest,thatis,withthespecifiedairvelocity,temperaturedifferencebetweenthewarmplateandthecoolair,andairgapformeasuringcoolairtemperature.1.4Thevaluesstatedinmetricunitsaretoberegardedasthestandard.Conversionfactors,forthermalconductanceandconductivityandthermalresistanceandresistivity,tootherunitsincommonusearegiveninTables1-51.5Thisstandarddoesnotpurporttoaddressthesafetyconcernsassociatedwithitsuse.Itistheresponsibilityofwhoeverusesthisstandardtoconsultandestablishappropri-atesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:D123TerminologyRelatingtoTextiles2D1777MethodforMeasuringThicknessofTextileMate-rials23.Terminology3.1Definitions:3.1.1bulkdensity,n—apparentmassperunitvolume.3.1.1.1Discussion—Intestingthethermaltransmittanceoffabrics,bulkdensityiscalculatedfromthefabricweightperunitareaandthethicknessvalueusedtocalculatethermalconductivity.3.1.2clo,n—unitofthermalresistancedefinedastheinsulationrequiredtokeeparestingman(producingheatattherateof58W/m2)comfortableinanenvironmentat21°C,airmovement0.1m/s,orroughlytheinsulationvalueoftypicalindoorclothing.3,4(Syn.intrinsicclo).3.1.2.1Discussion—Numericallythecloisequalto0.155K·m2/W.3.1.3heattransfercoeffıcient,n—seethermaltransmit-tance.3.1.4intrinsicclo,n—seeclo.3.1.5specificclo,n—thespecificthermalresistanceinclounitsperunitthickness.3.1.6thermalconductance,n—seethermaltransmittance.3.1.7thermalconductivity,n—timerateofunidirectionalheattransferperunitarea,inthesteady-state,betweenparallelplanesseparatedbyunitdistance,perunitdifferenceoftemperatureoftheplanes.3.1.7.1Discussion—Numerically,thermalconductivityequalstheproductoftheheattransfercoefficientandthedistanceseparatingtheplanes.Thus,k,thethermalconductiv-ityofthefabriconly,istheproductofU2andthefabricthickness.UnitsofthermalconductivityareW/m·K.3.1.8thermalresistance,n—reciprocalofthermaltransmit-tance.3.1.9thermalresistivity,n—reciprocalofthermalconduc-tivity.3.1.10thermaltransmittance,n—timerateofunidirectionalheattransferperunitarea,inthesteady-state,betweenparallelplanes,perunitdifferenceoftemperatureoftheplanes(Syn.thermalconductance,heattransfercoefficient).1ThistestmethodisunderthejurisdictionofASTMCommitteeD13onTextilesandisthedirectresponsibilityofSubcommitteeD13.51onChemicalConditioningandPerformance.CurrenteditionapprovedJuly26,1985.PublishedSeptember1985.OriginallypublishedasD1518–57T.LastpreviouseditionD1518–77.2AnnualBookofASTMStandards,Vol07.01.3AmericanSocietyofHeating,Refrigerating,andAir-ConditioningEngineers.4Gagge,A.P.,Burton,A.C.,Bazett,H.C.,Science,Vol94,Nov.7,1941,pp.428–430.1Copyright©ASTMInternational,100BarrHarborDrive,POBoxC700,WestConshohocken,PA19428-2959,UnitedStates.CopyrightASTMInternationalProvidedbyIHSunderlicensewithASTMLicensee=DefenseSupplyCtr/5913977001NotforResale,01/16/200819:47:32MSTNoreproductionornetworkingpermittedwithoutlicensefromIHS--``````,````,,``,,``,,`,,```,`-`-`,,`,,`,`,,`---3.1.10.1Discussion—Thermaltransmittanceisexpressedaswattspersquaremetreoftestspecimenperkelvindifferencebetweenthehotplateandthecoolatmosphere(W/m2·K).Thermaltransmittanceforthreedifferentcasesisdeter-minedinthismethod:U1=combinedthermaltransmittanceofthetestspecimenandair.Ubp=thermaltransmittanceoftheplatewithoutfabriccover(“bareplate”).Thispropertyreflectsthein-strumentconstantandisusedtostandardizetheplate,and,inconjunctionwithU1,isusedinthecalculationofU2.U2=thermaltransmittanceoffabriconly.ThisvaluecorrespondstotheCvalue(W/m2·K)definedandusedbyASTMandASHRAE.4Inthecalculationofthisvaluetheassumptionismadethattheboundarylayersofthebareplateandtheboundarylayersofthefabricareequal.ExperimentalresultsindicatethattheU2valuesarevalidwhentestedwithinthelimitsspecifiedinSection1.3.1.11totalclo,n—theintrinsiccloplusthethermalresis-tancefromtheairboundary.3.1.12Fordefinitionsofothertextiletermsusedinthismethod,refertoTerminologyD123.3.2DefinitionsofTermsSpecifictoThisStandard:3.2.1effectiveinsulationratio,n—indicatestheincreaseininsulationaffordedbythefabricincomparisontotheuncov-eredtestplateunderspecifiedconditionsoftest.3.2.2meantemperature,n—theaverageofthehotplatetemperatureandthetemperatureofthecalm,coolairthatprevailedduringthetest.4.SignificanceandUse4.1Thethermaltransmittanceofafabricorbattingisofconsiderableimportanceindeterminingitssuitabilityforuseinfabricatingcoldweatherprotectivegearandclothing.Thethermalinterchangebetweenmanandhisenvironmentis,however,anextremelycomplicatedsubjectwhichinvolvesmanyfactorsinadditiontotheequilibriuminsulationvaluesoffabricsandbattings.Therefore,measuredthermaltransmit-tancecoefficientscanonlyindicaterelativemeritofaparticularmaterial.4.2Themeasurementofheattransfercoefficientsisaverydifficultandhighlytechnicalfield,anditisnotpracticalinaTABLE1ConversionFactorsforThermalConductivityAToConvertThermalCon-ductivityMultiplybyFromtoW/m·KBW·cm/m2·KW/cm·Kcal/s·cm·Kkg-cal/h·m·Kkg-cal·cm/h·m2·KBtu/h·ft·°FBtu·in/h·ft2·°Fin/clomm/cloW/m·K1.1.310+21.310−22.388310−38.598310−18.598310+15.778310−16.9346.0931.548310+2W·cm/m2·K1.310−21.1.310−42.388310−58.598310−38.598310−15.778310−36.934310−26.093310−21.548W/cm·K1.310+21.310+41.2.388310−18.598310+18.598310+35.778310+16.934310+26.093310+21.548310+4cal/s·cm·K4.187310+24.187310+44.1871.3.6310+23.6310+42.419310+22.903310+32.551310+36.480310+4kg-cal/h·m·K1.1631.163310+21.163310−22.778310−31.1.310+26.720310−18.0647.0871.8310+2kg-cal·cm/h·m2·K1.163310−21.1631.163310−42.778310−51.310−21.6.720310−38.064310−27.087310−21.8Btu/h·ft·°F1.7311.731310+21.731310−24.134310−31.4881.488310+21.1.2310+11.055310+12.679310+2Btu·in/h·ft2·°F1.442310−11.442310+11.442310−33.445310−41.240310−11.240310+18.333310−21.8.788310−12.232310+1in/clo1.641310−11.641310+11.641310−33.920310−41.411310−11.411310−19.482310−21.1381.2.540310+1mm/clo6.461310−36.461310−16.461310−51.543310−55.556310−35.556310−13.733310−34.480310−33.937310−21.AUnitsaregivenintermsof:(1)theabsolutejoulepersecond,orwatt;(2)thecalorie(InternationalTable)=4.1868J;(3)theBritishthermalunit(InternationalTable)=1055.06J;and(4)theclo(unitofclothingresistance)=0.155K·m2/W.BRecommended(SI)units.TABLE2ConversionFactorsforThermalTransmittanceAToConvertThermalTransmittanceMultiplybyFromtoW/m2·KBW/cm2·Kcal/s·cm2·Kkg-cal/h·m2·KBtu/h·ft2·°Fclo−1W/m2·K1.1.310−42.388310−58.598310−11.761310−11.548310−1W/cm2·K1.310+41.2.388310−18.598310+31.761310+31.548310+3cal/s·cm2·K4.187310+44.1871.3.6310+47.373310+36.480310+3kg-cal/h·m2·K1.1631.163310−42.778310−51.2.048310−11.8310−1Btu/h·ft2·°F5.6785.678310−41.356310−44.8821.8.788310−1clo−16.4616.461310−41.543310−45.5561.1381.AUnitsaregivenintermsof:(1)theabsolutejoulepersecond,orwatt;(2)thecalorie(InternationalTable)=4.1868J;(3)theBritishthermalunit(InternationalTable)=1055.06J;and(4)theclo(unitofclothingresistance)=0.155K·m2/W.BRecommended(SI)units.D1518–85(2003)2CopyrightASTMInternationalProvidedbyIHSunderlicensewithASTMLicensee=DefenseSupplyCtr/5913977001NotforResale,01/16/200819:47:32MSTNoreproductionornetworkingpermittedwithoutlicensefromIHS--``````,````,,``,,``,,`,,```,`-`-`,,`,,`,`,,`---testmethodofthisscopetoestablishdetailssufficienttocoverallcontingencies.DeparturesfromtheinstructionsofTestMethodD1518mayleadtosignificantlydifferenttestresults.Technicalknowledgeconcerningthetheoryofheatflow,temperaturemeasurement,andtestingpracticesisneededtoevaluatewhichdeparturesfromtheinstructionsaresignificant.Standardizationofthemethodreduces,butdoesnoteliminatetheneedforsuchtechnicalknowledge.Anysignificantdepar-turesaretobereportedwiththeresults.4.3TestMethodD1518forthedeterminationofthether-maltransmittanceoftextilematerialsisconsideredsatisfactoryforacceptancetestingofcommercialshipmentsoftextilematerialsbecausethetestmethodhasbeenusedinthetradeforacceptancetesting.Anditisthebesttestmethodknownforthispurpose.4.3.1IncaseofadisputearisingfromdifferencesinreportedresultswhenusingTestMethodD1518foraccep-tancetestingofcommercialshipments,thepurchaserandthesuppliershouldconductcomparativeteststodetermineifthereisastatisticalbiasbetweentheirlaboratories.Competentstatisticalassistanceisrecommendedfortheinvestigationofbias.Asaminimum,thetwopartiesshouldtakeagroupoftestspecimenswhichareashomogeneousaspossibleandwhicharefromalotofmaterialofthetypeinquestion.Thetestspecimensshouldthenbesenttoeachlaboratoryfortesting.TheaverageresultsfromthetwolaboratoriesshouldbecomparedusingStudent’st-testforpaireddataandanaccept-ableprobabilitylevelchosenbythetwopartiesbeforetestingisbegun.Ifabiasisfound,eitheritscausemustbefoundandcorrectedorthepurchaserandthesuppliermustagreetointerpretfuturetestresultswithconsiderationtotheknownbias.TABLE3ConversionFactorsforThermalResistivityAToConvertThermalResistivityBMultiplybyFromtom·K/WBm2·K/W·cmcm·K/Wcm·K·s/calm·K·h/kg-calm2·K·h/kg-cal·cmft·°F·h/Btuft2·°F·h/Btu·inclo/inclo/mmm·K/W1.1.310−21.310+24.187310+21.1631.163310−21.7311.442310−11.641310−16.461310−3m2·K/W·cm1.310+21.1.310+44.187310+41.163310+21.1631.731310+21.442310+11.641310−16.461310−1cm·K/W1.310−21.310−41.4.1871.163310−21.163310−41.731310−21.442310−31.641310−36.461310−5cm·K·s/cal2.388310−32.388310−52.388310−11.2.778310−32.778310−54.134310−33.445310−43.920310−41.543310−5m·K·h/kg-cal8.598310−18.598310−38.598310+13.6310+21.1.310−21.4881.240310−11.411310−15.556310−3m2·K·h/kg-cal·cm8.598310+18.598310−18.598310+33.6310+41.310+21.1.488310+21.240310+11.411310+15.556310−1ft·°F·h/Btu5.778310−15.778310−35.778310+12.419310+26.720310−16.720310−31.8.333310−29.482310−23.733310−3ft2·°F·h/Btu·in6.9346.934310−26.934310+22.903310+38.0648.064310−21.2310+11.1.1384.480310−3clo/in6.0936.093310−26.093310+22.551310+37.0877.087310−21.055310+18.788310−11.3.937310−2clo/mm1.548310+21.5481.548310+46.480310+41.8310+21.82.679310+22.232310+12.540310+11.AUnitsaregivenintermsof:(1)theabsolutejoulepersecond,orwatt;(2)thecalorie(InternationalTable)=4.1868J;(3)theBritishthermalunit(InternationalTable)=1055.06J;and(4)theclo(unitofclothingresistance)=0.155K·m2/W.BRecommended(SI)units.TABLE4ConversionFactorsforThermalResistanceAToConvertThermalResistanceMultiplybyFromtom2·K/WBcm2·K/Wcm2·K·s/calm2·K·h/kg-calft2·°F·h/Btuclom2·K/W1.1.310+44.187310+41.1635.6786.461cm2·K/W1.310−41.4.1871.163310−45.678310−46.461310−4cm2·K·s/cal2.388310−52.388310−11.2.778310−51.356310−41.543310−4m2·K·h/kg-cal8.598310−18.598310+33.6310+41.4.8825.556ft2·°F·h/Btu1.761310−11.761310+37.373310+32.048310−11.1.138clo1.548310−11.548310+36.480310+31.8310−18.788310−11.AUnitsaregivenintermsof:(1)theabsolutejoulepersecond,orwatt;(2)thecalorie(InternationalTable)=4.1868J;(3)theBritishthermalunit(InternationalTable)=1055.06J;and(4)theclo(unitofclothingresistance)=0.155K·m2/W.BRecommended(SI)units.TABLE5MiscellaneousConversionFactorsPropertiesToConvertfromaValueEx-pressedasToaValueExpressedasMultiplybyMassperunitoz/yd2g/m233.91areamg/cm2g/m210.0Thicknessin.mm25.41/1000in.(mil)mm0.0254Bulkdensitylb/ft3kg/m316.02(oz/yd2)/inkg/m31.335(g/m2)/mmkg/m31.0D1518–85(2003)3CopyrightASTMInternationalProvidedbyIHSunderlicensewithASTMLicensee=DefenseSupplyCtr/5913977001NotforResale,01/16/200819:47:32MSTNoreproductionornetworkingpermittedwithoutlicensefromIHS--``````,````,,``,,``,,`,,```,`-`-`,,`,,`,`,,`---5.Apparatus(Fig.1,Fig.2,andFig.3)NOTE1—Thedrawingsandillustrationsareintendedassuggesteddesignsonly.Thefinaldesignofequipment,includingnecessarywiring,willbedictatedbythechoiceoftheelectricalmeasuringandcontrolequipment.5.1HotPlate—Aguardringflatplatecomposedofatestplate,guardring,andbottomplateasfollows,eachelectricallymaintainedataconstanttemperatureintherangeofhumanskintemperature[33to36°C(91.4to98.8°F)].5.1.1TestPlate—Thetestplateportionofthehotplateshallbeatleast150mm(6.0in.)squareandshallbeplacedatthecenteroftheuppersurfaceofthehot-plateassembly.Itshallbemadeofaluminumorcopperandpaintedadullblacktoapproximatetheemissivityofthehumanskin.Theheatingelementshallconsistofparallelwires,preferablyofconstantanmetal,insulatedfrom,butmountedwithin3mm(0.1in.)oftheupperplate.5.1.2GuardRing—Theguardringborderingthetestplateshallbeatleast63.5mm(2.5in.)inwidthandshallbeofthesamethickness,composition,andtypeofconstructionasthetestplate.Itshallbecoplanarwiththetestplate,andshallbeseparatedfromitbymeansofastripofcorkorothersuitableinsulatingmaterialapproximately3-mm(0.1-in.)wide.Theguardringshallbedesignedtopreventlaterallossofheatfromthetestplate.5.1.3BottomPlate—Thebottomplateshallbeofthesamethickness,composition,andtypeofconstructionasthetestplateandguardring.Thebottomplateshallbeinaplaneparalleltothetestplateandguardring,andatadistanceofatleast25mm(1.0in.)butnotinexcessof75mm(3.0in.)beneaththem.Itshallbeseparatedfromthetestplateandguardringbyawoodenframeworkandtheairpocketformedthereby,orbyothermeansofcausingairentrapment.ThedimensionsofferedassuggesteddesignspecificationsareshowninFig.3.Thepurposeofthebottomplateistopreventadownwardlossofheatfromthetestplateandguardring.5.2TemperatureControl—Separatecontrolofthetempera-turesofthethreesectionsofthehotplate(testplate,guardring,andbottomplate)shallbeestablishedbyindependentadjust-mentsoftheheatercurrentsthroughadjustabletransformers,variableimpedances,orintermittentheatingcycles.Automaticregulationoftemperaturesisrecommended.Useaconstantvoltagesupply,controlledto61%tominimizefluctuationsintemperature.5.3Power-MeasuringInstruments—Oneofanyofthefol-lowinginstrumentsshallbeusedformeasuringpower:5.3.1Wattmeter,5.3.2Watt-hourmeterandclock,5.3.3Voltmeterandammeter,or5.3.4Eitheravoltmeteroranammetercanbeusedifthetestplateheaterresistanceatoperatingtemperatureisexactlyknown.Thesedevicesshallbeoperatedinaccordancewithstandardpracticeandshallbecalibratedtomeasurepowerwithanaccuracyof62%.5.4Clocks—Whenheaterpowerissuppliedonanintermit-tentbasis,arunning-timeclock,energizedinsynchronismwiththeheater,shallbeusedtoindicatethetotaltimeofheating.Anothersimilarclockshallbeusedtoindicateeitherthetotaltimeorthetimeduringwhichtheheaterisnotenergized.Thetotallimitoferrorofsuchclocksshallbelessthan1%underserviceconditions.5.5EquipmentforMeasuringtheSeveralPlateTempera-tures:FIG.1GuardRingHotPlateForThermalTransmittanceTestFIG.2HotPlate,TopView,ShowingLocationofThermistorsandThermocouplesonTestSectionandGuardRingD1518–85(2003)4CopyrightASTMInternationalProvidedbyIHSunderlicensewithASTMLicensee=DefenseSupplyCtr/5913977001NotforResale,01/16/200819:47:32MSTNoreproductionornetworkingpermittedwithoutlicensefromIHS--``````,````,,``,,``,,`,,```,`-`-`,,`,,`,`,,`---5.5.1Thermocouples—Thetestplate,guardring,andbot-tomplateshalleachcontainoneormorethermocouplesmadeofajunctionofwiresofcopperandconstantan,eachofB&SGageNo.30[0.255mm(0.01in.)].Aftercalibration,thesethermocouplesshallbepositionedwithinthematerialoftheplatesasclosetotheexternalplatesurfacesasphysicallypossible[1.6mm(0.06in.)]tomeasurethetemperaturesoftherespectivesurfaces.5.5.2IceBath,asareferencejunctionforthethermo-couples,orequivalentdevice.5.5.3Potentiometer,accuratewithin62.5µV,tomeasurethethermocoupleemf’s.5.5.4Switch—Athermocoupleselectorswitchforsepa-ratelyconnectingtoeachsetofthermocouples.5.6TestChamber—Achambertohousethehotplatethatcanbemaintainedatselectedtemperaturesbetween4.5and21.1°C(40to70°F)withaconstancyof60.5°C(62.5°F).Thewallsofthetestchambershallnotbehighlyreflective,andthewalltemperatureshallbeequaltothatoftheairinthechamber.Thechambershallbeequippedwiththefollowinginstrumentsformaintainingtherelativehumidityat50630%formaintainingtheairtemperature,andforcontrollingtheairvelocityattheapproximaterateof0.1m/s(0.33ft/s).Thehoodformaintainingnearlystillairconditions,showninFig.1,isneeded.5.6.1RelativeHumidityMeasuringEquipment—Eitherawet-and-drybulbpsychrometeroracalibratedhumidity-sensitiveelectricalconductor.5.6.2AirTemperatureDetector—Athermocouplesimilartothoseintheplatesissuspendedwiththemeasuringjunctionexposedtotheairatapoint500mm(20.0in.)abovethecenterofthetestplate,insidehood.5.6.3AirVelocityIndicator—Anycalibratedmeansofmea-suringairvelocityatthespecifiedrate.6.Sampling6.1LotSample—foracceptancetestingtakealotsampleasdirectedintheapplicablematerialspecification,orasagreeduponbetweenpurchaserandsupplier.Intheabsenceofsuchaspecificationorotheragreement,takealaboratorysampleasdirectedin6.2.6.2Takealaboratorysamplefromeachrollorpieceoffabricinthelotsample.Thelaboratorysampleshouldbefullwidthandatleast600mm(24in.)longandshouldnotbetakenanyclosertotheendoftherollorpieceoffabricthan1m(1yd).6.3Sampleshipmentsofgarmentsorothertextilematerialsasagreeduponbetweenpurchaserandseller.6.4Testthreespecimensfromeachlaboratorysample,unlessotherwisespecifiedinthematerialspecification.FIG.3ApparatusforMeasurementofThermalTransmittance,ShowingDimensionsD1518–85(2003)5CopyrightASTMInternationalProvidedbyIHSunderlicensewithASTMLicensee=DefenseSupplyCtr/5913977001NotforResale,01/16/200819:47:32MSTNoreproductionornetworkingpermittedwithoutlicensefromIHS--``````,````,,``,,``,,`,,```,`-`-`,,`,,`,`,,`---7.PreparationofTestSpecimens7.1ModificationofaThickMaterialtoFacilitateTesting—Materialsmorethan25-mm(1–in.)thick,suchasso