1、Designation:E258414Standard Practice forThermal Conductivity of Materials Using a ThermalCapacitance(Slug)Calorimeter1This standard is issued under the fixed designation E2584;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year
2、of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This practice describes a technique for the determinationof the apparent thermal conductivity,a,of materials.It is forso
3、lid materials with apparent thermal conductivities in theapproximate range 0.02 a 2 W/(mK)over the approxi-mate temperature range between 300 K and 1100 K.NOTE1While the practice should also be applicable to determiningthe thermal conductivity of non-reactive materials,it has been foundspecifically
4、useful in testing fire resistive materials that are both reactiveand undergo significant dimensional changes during a high temperatureexposure.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.3 This standard does not purport
5、 to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2C1113 Test
6、 Method for Thermal Conductivity of Refracto-ries by Hot Wire(Platinum Resistance ThermometerTechnique)D2214 Test Method for Estimating the Thermal Conductiv-ity of Leather with the Cenco-FitchApparatus(Withdrawn2008)3E177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE220 Test
7、 Method for Calibration of Thermocouples ByComparison TechniquesE230 Specification and Temperature-Electromotive Force(EMF)Tables for Standardized ThermocouplesE457 Test Method for Measuring Heat-Transfer Rate Usinga Thermal Capacitance(Slug)CalorimeterE691 Practice for Conducting an Interlaboratory
8、 Study toDetermine the Precision of a Test Method3.Terminology3.1 Definitions:3.1.1 thermal conductivity,the time rate of heat flow,under steady conditions,through unit area,per unit temperaturegradient in the direction perpendicular to the area.3.1.2 apparent thermal conductivity,awhen other modeso
9、f heat transfer(and mass transfer)through a material arepresent in addition to thermal conduction,the results of themeasurements performed according to this practice will repre-sent the apparent or effective thermal conductivity for thematerial tested.3.2 Symbols:A=specimen area normal to heat flux
10、direction,m2Cp=specific heat capacity,J/(kgK)F=heating or cooling rate,(K/s)L=thickness of a specimen(slab)in heat transfer direc-tion,mM=mass,kgQ=heat flow,WT=absolute temperature,KTinnerSSS=mean temperature of the stainless steel slug,KTouterSPEC=mean temperature of outer(exposed)specimensurfaces,
11、KTmeanSPEC=mean temperature of specimen,KT=temperature difference across the specimen,given by(TouterSPEC TinnerSSS),K=thermal conductivity,W/(mK)a=apparent thermal conductivity,W/(mK)SPEC=bulk density of specimen being tested,kg/m33.3 Subscripts/Superscripts:SPEC=material specimen being evaluatedSS
12、S=stainless steel slug(thermal capacitance transducer)1This practice is under the jurisdiction of ASTM Committee E37 on ThermalMeasurements and is the direct responsibility of Subcommittee E37.05 on Thermo-physical Properties.Current edition approved Feb.15,2014.Published March 2014.Originallyapprov
13、ed in 2007.Last previous edition approved in 2010 as E2584 10.DOI:10.1520/E2584-14.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page on
14、the ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 4.Summary of Practice4.1 Principle of OperationIn principle,a slug of thermallyconductive
15、metal,capableofwithstandingelevatedtemperatures,is surrounded with another material of a uniformthickness(the specimen)whose thermal conductivity is sub-stantially lower than that of the slug.When the outer surface ofthis assembly is exposed to a temperature above that of theslug,heat will pass thro
16、ugh the outer layer,causing a tempera-ture rise in the slug itself.The temperature rise of the slug iscontrolled by the amount and rate of heat conducted to itssurface(flux),its mass,and its specific heat capacity.With theknowledge of these properties,the rate of temperature rise ofthe slug is in direct proportion to the heat flux entering it.Thus,under these conditions,the slug becomes a flux-gaugingdevice.From this measured flux,along with the measuredthermal gradient across the outer(specimen