ASTM_F_433_-_02_2014e1.pdf

Designation:F43302(Reapproved 2014)1Standard Practice forEvaluating Thermal Conductivity of Gasket Materials1This standard is issued under the fixed designation F433;the number immediately following the designation indicates the year of originaladoption or,in the case of revision,the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscriptepsilon()indicates an editorial change since the last revision or reapproval.1NOTEEditorially corrected Footnote 6 in July 2014.1.Scope1.1 This practice covers a means of measuring the amountof heat transfer quantitatively through a material or system.1.2 This practice is similar to the Heat Flow Meter Systemof Test Method C518,but modified to accommodate small testsamples of higher thermal conductance.1.3 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.1.4 This standard does not purport 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:2C518 Test Method for Steady-State Thermal TransmissionProperties by Means of the Heat Flow Meter ApparatusD2214 Test Method for Estimating the Thermal Conductiv-ity of Leather with the Cenco-FitchApparatus(Withdrawn2008)3F104 Classification System for Nonmetallic Gasket Materi-als3.Terminology3.1 Definitions:3.1.1 thermal conductivity,k,of a solid materialthe timerate of steady heat flow,watts(or Btu/h),through a unit area,m2(or ft2),per unit temperature gradient in the directionperpendicular to an isothermal surface C/m(or F/in.).Thek-factor is expressed W/mK(Btuin./hft2F).3.2 Symbols:k=thermal conductivity,W/mK(Btuin./hft2F)C=thermal conductance,W/m2K(Btu/hft2F)x=sample thickness,mm(in.)A=sample cross-sectional area,m2(ft2)q=heat flow,W(Btu/h)=heat flow transducer output,mVN=heat flow transducer calibration constant,W/m2mV(Btu/hft2mV)N=heat flux,W/m2(Btu/hft2)T=temperature difference,C(F)or mVT1=temperature of lower sample surface,C(F)ormVT2=temperature of upper sample surface,C(F)or mVTh=temperature of HFT surface facing sample,C(F)or mVTc=temperature of upper heater surface facingsample,C(F)or mVT=temperature,C(F)=total temperature drop across interfaces be-tween sample and adjacent surfaces,C(F)ormV=coefficient of thermal resistance at interfaces,m2K/W(hft2F/Btu)=correction constantsubscripts=unknown samplesubscriptr=known calibration sample4.Summary of Practice4.1 The sample and the heat flow transducer(HFT)aresandwiched between two controlled heater plates.The lowerheater is set at a higher temperature than the upper plate toproduce a flow of heat through the sample.The differential ofthese two temperatures,T,sensed by thermocouples,isamplified along with the electrical output,of the HFT and isdirectly proportional to the heat flow through the sample,expressed as W/m2(Btu/hft2).See Appendix for further1This practice is under the jurisdiction ofASTM Committee F03 on Gaskets andis the direct responsibility of Subcommittee F03.10 on Composite Gaskets.Current edition approved July 1,2014.Published November 2014.Originallyapproved in 1964.Last previous edition approved in 2009 as F433 02(2009).DOI:10.1520/F0433-02R14E01.2For 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 onthe 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 information.This recommended practice can be used formeasuring heat transfer at a hot side temperature up to 200C(392F).See Figs.1-5.5.Significance and Use5.1 This practice is designed to compare related materialsunder controlled conditions and their ability to maintain aminimum amount of thermal conductance.Test results shouldbe correlated with field results in order to predict heat transferproperties in particular applications.5.2 This practice may be used as a routine test when agreedupon by the user and the producer.6.Apparatus6.1 Heat Flow Transducer(HFT),with controlled heaterplates,thermocouples,and an analog computer module.47.Test Specimen7.1 The sample size shall be a 50.8-mm(2-in.)diameterdisk 60.25 mm(60.010 in.)from 2.29 to 12.7 mm(0.090 to0.500 in.)thick.8.Conditioning8.1 Condition the cut specimens in accordance with theirclassification,as required in Classification F104.9.Procedure9.1 Test temperatures are suggested from 100 to 175C(212to 347F)or whatever is agreed upon between the producer anduser.(The guard heater is usually set at or near the averagesample temperature between the lower and upper heaterplates.)9.1.1 Release the compressive lo