ASTM E1225-13

Standard Test Method for Thermal Conductivity of Solids Using the Guarded-Comparative-Longitudinal Heat Flow Technique

SIGNIFICANCE AND USE
5.1 The comparative method of measurement of thermal conductivity is especially useful for engineering materials including ceramics, polymers, metals and alloys, refractories, carbons, and graphites including combinations and other composite forms of each.  
5.2 Proper design of a guarded-longitudinal system is difficult and it is not practical in a method of this type to try to establish details of construction and procedures to cover all contingencies that might offer difficulties to a person without technical knowledge concerning theory of heat flow, temperature measurements, and general testing practices. Standardization of this test method is not intended to restrict in any way the future development by research workers of new or methods or improved procedures. However, new or improved techniques must be thoroughly tested. Requirements for qualifying an apparatus are outlined in Section 10.
SCOPE
1.1 This test method describes a steady state technique for the determination of the thermal conductivity, λ, of homogeneous-opaque solids (see Notes 1 and 2). This test method is applicable to materials with effective thermal conductivities in the range 0.2 m·K) over the temperature range between 90 and 1300 K. It can be used outside these ranges with decreased accuracy. Note 1—For purposes of this technique, a system is homogeneous if the apparent thermal conductivity of the specimen, λ A, does not vary with changes of thickness or cross-sectional area by more than ±5 %. For composites or heterogeneous systems consisting of slabs or plates bonded together, the specimen should be more than 20 units wide and 20 units thick, respectively, where a unit is the thickness of the thickest slab or plate, so that diameter or length changes of one-half unit will affect the apparent λA   by less than ±5 %. For systems that are non-opaque or partially transparent in the infrared, the combined error due to inhomogeneity and photon transmission should be less than ±5 %. Measurements on highly transparent solids must be accompanied with infrared absorption coefficient information, or the results must be reported as apparent thermal conductivity, λA.
Note 2—This test method may also be used to evaluate the contact thermal conductance/resistance of materials.  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 30-Sep-2013
• ICS: 17.200.10 - Heat. Calorimetry
• Technical Committee: E37 - Thermal Measurements
• Drafting Committee: E37.05 - Thermophysical Properties

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: E1225 − 13
Standard Test Method for
Thermal Conductivity of Solids Using the Guarded-
1
Comparative-Longitudinal Heat Flow Technique
This standard is issued under the fixed designation E1225; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
1.1 This test method describes a steady state technique for
the determination of the thermal conductivity, λ,of
2. Referenced Documents
homogeneous-opaque solids (see Notes 1 and 2). This test
2
2.1 ASTM Standards:
method is applicable to materials with effective thermal con-
E230Specification and Temperature-Electromotive Force
ductivities in the range 0.2 < λ < 200 W/(m·K) over the
(EMF) Tables for Standardized Thermocouples
temperature range between 90 and 1300 K. It can be used
outside these ranges with decreased accuracy.
3. Terminology
NOTE 1—For purposes of this technique, a system is homogeneous if
3.1 Descriptions of Terms and Symbols Specific to This
the apparent thermal conductivity of the specimen, λ , does not vary with
A
Standard:
changes of thickness or cross-sectional area by more than 65%. For
3.1.1 Terms:
composites or heterogeneous systems consisting of slabs or plates bonded
together, the specimen should be more than 20 units wide and 20 units 3.1.1.1 thermal conductivity, λ—the time rate of heat flow,
thick, respectively, where a unit is the thickness of the thickest slab or
understeadyconditions,throughunitarea,perunittemperature
plate, so that diameter or length changes of one-half unit will affect the
gradient in the direction perpendicular to the area;
apparent λ by less than 65%. For systems that are non-opaque or
A
3.1.1.2 apparent thermal conductivity—when other modes
partially transparent in the infrared, the combined error due to inhomo-
of heat transfer through a material are present in addition to
geneityandphotontransmissionshouldbelessthan 65%.Measurements
onhighlytransparentsolidsmustbeaccompaniedwithinfraredabsorption conduction,theresultsofthemeasurementsperformedaccord-
coefficientinformation,ortheresultsmustbereportedasapparentthermal
ing to this test method will represent the apparent or effective
conductivity, λ .
A
thermal conductivity for the material tested.
3.1.2 Symbols:
NOTE 2—This test method may also be used to evaluate the contact
thermal conductance/resistance of materials.
λ (T) = thermal conductivity of meter bars (reference
M
1.2 The values stated in SI units are to be regarded as
materials) as a function of temperature, (W/
standard. No other units of measurement are included in this
(m·K)),
standard. 1
λ = thermal conductivity of top meter bar (W/
M
1.3 This standard does not purport to address all of the (m·K)),
2
safety concerns, if any, associated with its use. It is the λ = thermal conductivity of bottom meter bar (W/
M
(m·K)),
responsibility of the user of this standard to establish appro-
λ (T) = thermal conductivity of specimen corrected
priate safety and health practices and determine the applica-
S
for heat exchange where necessary, (W/
bility of regulatory limitations prior to use.
(m·K)),
1.4 This international standard was developed in accor-
λ' (T) = thermal conductivity of specimen calculated
dance with internationally recognized principles on standard- S
by ignoring heat exchange correction, (W/
ization established in the Decision on Principles for the
(m·K)),
Development of International Standards, Guides and Recom-
λ (T) = thermal conductivity of insulation as a func-
I
tion of temperature, (W/(m·K)),
1
ThistestmethodisunderthejurisdictionofASTMCommitteeE37onThermal
Measurements and is the direct responsibility of Subcommittee E37.05 on Thermo-
2
physical Properties. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Oct. 1, 2013. Published November 2013. Originally contact ASTM Customer service at [e-mail]. For Annual Book of ASTM
approved in 1987. Last previous edition approved in 2009 as E1225–09. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/E1225-13. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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E1225 − 13
Z 2 Z λ T 2 T T 2 T
T = absolute temperature (K), 4 3 M 2 1 6 5
λ 5 · · 1 (1)
S D
s
T 2 T 2 Z 2 Z Z 2 Z
Z = positionasmeasuredfromtheupperendofth
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: E1225 − 09 E1225 − 13
Standard Test Method for
Thermal Conductivity of Solids by Means of Using the
1
Guarded-Comparative-Longitudinal Heat Flow Technique
This standard is issued under the fixed designation E1225; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope
1.1 This test method describes a steady state technique for the determination of the thermal conductivity, λ, of homogeneous-
opaque solids (see Notes 1 and 2). This test method is for applicable to materials with effective thermal conductivities in the
approximate range 0.2 < λ < 200 W/(m·K) over the approximate temperature range between 90 and 1300 K. It can be used outside
these ranges with decreased accuracy.
NOTE 1—For purposes of this technique, a system is homogeneous if the apparent thermal conductivity of the specimen, λ , does not vary with changes
A
of thickness or cross-sectional area by more than 65 %. For composites or heterogeneous systems consisting of slabs or plates bonded together, the
specimen should be more than 20 units wide and 20 units thick, respectively, where a unit is the thickness of the thickest slab or plate, so that diameter
or length changes of one-half unit will affect the apparent λ by less than 65 %. For systems that are non-opaque or partially transparent in the infrared,
A
the combined error due to inhomogeneity and photon transmission should be less than 65 %. Measurements on highly transparent solids must be
accompanied with infrared absorption coefficient information, or the results must be reported as apparent thermal conductivity, λ .
A
NOTE 2—This test method may also be used to evaluate the contact thermal conductance/resistance of materials.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory
limitations prior to use.
2. Referenced Documents
2
2.1 ASTM Standards:
C177 Test Method for Steady-State Heat Flux Measurements and Thermal Transmission Properties by Means of the
Guarded-Hot-Plate Apparatus
C408 Test Method for Thermal Conductivity of Whiteware Ceramics
C1045 Practice for Calculating Thermal Transmission Properties Under Steady-State Conditions
D4351 Test Method for Measuring the Thermal Conductivity of Plastics by the Evaporation-Calorimetric Method (Withdrawn
3
1990)
E220 Test Method for Calibration of Thermocouples By Comparison Techniques
E230 Specification and Temperature-Electromotive Force (EMF) Tables for Standardized Thermocouples
F433 Practice for Evaluating Thermal Conductivity of Gasket Materials
3. Terminology
3.1 Descriptions of Terms and Symbols Specific to This Standard:
3.1.1 Terms:
3.1.1.1 thermal conductivity, λ—the time rate of heat flow, under steady conditions, through unit area, per unit temperature
gradient in the direction perpendicular to the area;
1
This test method is under the jurisdiction of ASTM Committee E37 on Thermal Measurements and is the direct responsibility of Subcommittee E37.05 on
Thermophysical Properties.
Current edition approved March 15, 2009Oct. 1, 2013. Published April 2010November 2013. Originally approved in 1987. Last previous edition approved in 20042009
as E1225 – 04.E1225 – 09. DOI: 10.1520/E1225-09.10.1520/E1225-13.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
E1225 − 13
3.1.1.2 apparent thermal conductivity—when other modes of heat transfer through a material are present in addition to
conduction, the results of the measurements performed according to this test method will represent the apparent or effective thermal
conductivity for the material tested.
3.1.2 Symbo
...