1、Designation:C104519Standard Practice forCalculating Thermal Transmission Properties Under Steady-State Conditions1This standard is issued under the fixed designation C1045;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of l
2、ast 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 provides the user with a uniform procedurefor calculating the thermal transmission properties of a materialor
3、system from data generated by steady state,one dimensionaltest methods used to determine heat flux and surface tempera-tures.This practice is intended to eliminate the need for similarcalculation sections in Test Methods C177,C335,C518,C1033,C1114 and C1363 and Practices C1043 and C1044 bypermitting
4、 use of these standard calculation forms by refer-ence.1.2 The thermal transmission properties described include:thermal conductance,thermal resistance,apparent thermalconductivity,apparent thermal resistivity,surface conductance,surface resistance,and overall thermal resistance or transmit-tance.1.
5、3 This practice provides the method for developing theapparent thermal conductivity as a function of temperaturerelationship for a specimen from data generated by standardtest methods at small or large temperature differences.Thisrelationship can be used to characterize material for compari-son to m
6、aterial specifications and for use in calculationprograms such as Practice C680.1.4 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.5 This practice includes a discussion of the definitions andunderlying assumptions for the calc
7、ulation of thermal trans-mission properties.Tests to detect deviations from theseassumptions are described.This practice also considers thecomplicating effects of uncertainties due to the measurementprocesses and material variability.See Section 7.1.6 This practice is not intended to cover all possi
8、ble aspectsof thermal properties data base development.For newmaterials,the user should investigate the variations in thermalproperties seen in similar materials.The information containedin Section 7,theAppendix and the technical papers listed in theReferences section of this practice may be helpful
9、 in determin-ing whether the material under study has thermal propertiesthat can be described by equations using this practice.Someexamples where this method has limited application include:(1)the onset of convection in insulation as described inReference(1);(2)while a phase change is taking place i
10、n oneof the insulation components causing an unsteady-state condi-tion;and(3)the influence of heat flow direction and tempera-ture difference changes for reflective insulations.1.7 This international standard was developed in accor-dance with internationally recognized principles on standard-ization
11、 established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2C168 Terminology Relating to Thermal InsulationC177 Test Meth
12、od for Steady-State Heat Flux Measure-ments and Thermal Transmission Properties by Means ofthe Guarded-Hot-Plate ApparatusC335 Test Method for Steady-State Heat Transfer Propertiesof Pipe InsulationC518 Test Method for Steady-State Thermal TransmissionProperties by Means of the Heat Flow Meter Appar
13、atusC680 Practice for Estimate of the Heat Gain or Loss and theSurface Temperatures of Insulated Flat,Cylindrical,andSpherical Systems by Use of Computer ProgramsC1033 Test Method for Steady-State Heat Transfer Proper-ties of Pipe Insulation Installed Vertically(Withdrawn2003)3C1043 Practice for Gua
14、rded-Hot-Plate Design Using Circu-lar Line-Heat Sources1This practice is under the jurisdiction of ASTM Committee C16 on ThermalInsulation and is the direct responsibility of Subcommittee C16.30 on ThermalMeasurement.Current edition approved April 1,2019.Published May 2019.Originallyapproved in 1985
15、.Last previous edition approved in 2013 as C1045 07(2013).DOI:10.1520/C1045-19.2For 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
16、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 StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to T
