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ASTM C177-97

(Test Method)

Standard Test Method for Steady-State Heat Flux Measurements and Thermal Transmission Properties by Means of the Guarded-Hot-Plate Apparatus

Standard Test Method for Steady-State Heat Flux Measurements and Thermal Transmission Properties by Means of the Guarded-Hot-Plate Apparatus

SCOPE
1.1 This test method covers the achievement and measurement of steady-state heat flux through flat-slab specimens using a guarded-hot-plate apparatus. The method encompasses both the single-sided and the double-sided mode of measurement. Both distributed and line source guarded heating plate designs are included, in principle, in this test method. The reader should consult the standard practices on the single-sided mode of operation and on the line source apparatus for further details on these variations of the method.  
1.2 The calculations of thermal transmission properties based upon measurements using this method shall be performed in conformance with Practice C1045.  
1.3 This is an absolute (or primary) method of measurement since no heat flux reference standards are required except to confirm accuracy statements and to establish traceability to recognized standards. This absolute method is contrasted with a comparative (or secondary) method, such as Test Method C518, in which the results are directly dependent on heat flux reference standards.  
1.4 This test method is applicable to the measurement of a wide variety of specimens, ranging from opaque solids to porous or transparent materials, and a wide range of environmental conditions. Special precautions in the measurement process are described for the following:  
1.4.1 Specimens exhibiting appreciable inhomogeneities, anisotropies, rigidity, or extremes of thermal flux density.  
1.4.2 Measurements conducted at extremes of temperature (either high or low) or under vacuum conditions.  
1.5 This test method is intended to allow a wide variety of apparatus designs and design accuracies to satisfy the requirements of specific measurement problems. Compliance with this test method requires a statement of the uncertainty of each reported variable in the report. Therefore, in the following sections, the significant error factors will be discussed.  
1.6 This standard does not purport to address all of the safety problems, 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
09-Feb-1997
ICS
17.200.10 - Heat. Calorimetry
Technical Committee
C16 - Thermal Insulation
Drafting Committee
C16.30 - Thermal Measurement
Current Stage
Ref Project

Relations

Replaced By
ASTM C177-04 - Standard Test Method for Steady-State Heat Flux Measurements and Thermal Transmission Properties by Means of the Guarded-Hot-Plate Apparatus
Effective Date
01-Nov-2004
Referred By
ASTM C1014-17 - Standard Specification for Spray-Applied Mineral Fiber Thermal and Sound Absorbing Insulation
Effective Date
10-Feb-1997
Referred By
ASTM D4612-16 - Standard Test Method for Calculating Thermal Diffusivity of Rock and Soil
Effective Date
10-Feb-1997
Referred By
ASTM C1484-10(2018) - Standard Specification for Vacuum Insulation Panels
Effective Date
10-Feb-1997
Referred By
ASTM E1091-21 - Standard Specification for Nonmetallic Honeycomb Core for Use in Shelter Panels
Effective Date
10-Feb-1997
Referred By
ASTM D3575-20 - Standard Test Methods for Flexible Cellular Materials Made from Olefin Polymers
Effective Date
10-Feb-1997
Referred By
ASTM C592-22a - Standard Specification for Mineral Fiber Blanket Insulation and Blanket-Type Pipe Insulation (Metal-Mesh Covered) (Industrial Type)
Effective Date
10-Feb-1997
Referred By
ASTM D5144-08(2021) - Standard Guide for Use of Protective Coating Standards in Nuclear Power Plants
Effective Date
10-Feb-1997
Referred By
ASTM F2165-19 - Standard Specification for Flexible Pre-Insulated Plastic Piping
Effective Date
10-Feb-1997
Referred By
ASTM C612-14(2019) - Standard Specification for Mineral Fiber Block and Board Thermal Insulation
Effective Date
10-Feb-1997
Referred By
ASTM E1730-19 - Standard Specification for Rigid Foam for Use in Structural Sandwich Panel Cores
Effective Date
10-Feb-1997
Referred By
ASTM C534/C534M-23 - Standard Specification for Preformed Flexible Elastomeric Cellular Thermal Insulation in Sheet and Tubular Form
Effective Date
10-Feb-1997
Referred By
ASTM C1427-21 - Standard Specification for Extruded Preformed Flexible Cellular Polyolefin Thermal Insulation in Sheet and Tubular Form
Effective Date
10-Feb-1997
Referred By
ASTM C447-15(2022) - Standard Practice for Estimating the Maximum Use Temperature of Thermal Insulations
Effective Date
10-Feb-1997
Referred By
ASTM C553-13(2019) - Standard Specification for Mineral Fiber Blanket Thermal Insulation for Commercial and Industrial Applications
Effective Date
10-Feb-1997

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ASTM C177-97 - Standard Test Method for Steady-State Heat Flux Measurements and Thermal Transmission Properties by Means of the Guarded-Hot-Plate ApparatusASTM C177-97 - Standard Test Method for Steady-State Heat Flux Measurements and Thermal Transmission Properties by Means of the Guarded-Hot-Plate Apparatus
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ASTM C177-97 - Standard Test Method for Steady-State Heat Flux Measurements and Thermal Transmission Properties by Means of the Guarded-Hot-Plate Apparatus
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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: C 177 – 97
Standard Test Method for
Steady-State Heat Flux Measurements and Thermal
Transmission Properties by Means of the Guarded-Hot-Plate
1
Apparatus
This standard is issued under the fixed designation C177; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope guarded-hot-plate, for practical reasons the specimen conduc-
2
tance should be less than 16 W/(m K).
1.1 This test method establishes the criteria for the labora-
1.7 This test method is applicable to the measurement of a
tory measurement of the steady-state heat flux through flat,
wide variety of specimens, ranging from opaque solids to
homogeneous specimen(s) when their surfaces are in contact
porous or transparent materials, and a wide range of environ-
with solid, parallel boundaries held at constant temperatures
mental conditions including measurements conducted at ex-
using the guarded-hot-plate apparatus.
tremes of temperature and with various gases and pressures.
1.2 Thetestapparatusdesignedforthispurposeisknownas
1.8 Inhomogeneities normal to the heat flux direction, such
a guarded-hot-plate apparatus and is a primary (or absolute)
as layered structures, can be successfully evaluated using this
method. This test method is comparable, but not identical, to
testmethod.However,testingspecimenswithinhomogeneities
ISO 8302.
in the heat flux direction, such as an insulation system with
1.3 This test method sets forth the general design require-
thermal bridges, can yield results that are location specific and
ments necessary to construct and operate a satisfactory
shall not be attempted with this type of apparatus. See Test
guarded-hot-plate apparatus. It covers a wide variety of appa-
Methods C976 or C236 for guidance in testing these systems.
ratus constructions, test conditions, and operating conditions.
1.9 Calculations of thermal transmission properties based
Detailed designs conforming to this test method are not given
upon measurements using this method shall be performed in
but must be developed within the constraints of the general
conformance with Practice C1045.
requirements. Examples of analysis tools, concepts and proce-
1.10 In order to ensure the level of precision and accuracy
dures used in the design, construction, calibration and opera-
2 expected, persons applying this standard must possess a
tionofaguarded-hot-plateapparatusaregiveninRefs (1-41).
knowledge of the requirements of thermal measurements and
1.4 This test method encompasses both the single-sided and
testing practice and of the practical application of heat transfer
the double-sided modes of measurement. Both distributed and
theory relating to thermal insulation materials and systems.
line source guarded heating plate designs are permitted. The
Detailed operating procedures, including design schematics
user should consult the standard practices on the single-sided
and electrical drawings, should be available for each apparatus
mode of operation, Practice C1044, and on the line source
to ensure that tests are in accordance with this test method. In
apparatus, Practice C1043, for further details on these heater
addition, automated data collecting and handling systems
designs.
connected to the apparatus must be verified as to their
1.5 The guarded-hot-plate apparatus can be operated with
accuracy. This can be done by calibration and inputting data
either vertical or horizontal heat flow. The user is cautioned
sets, which have known results associated with them, into
however,sincethetestresultsfromthetwoorientationsmaybe
computer programs.
different if convective heat flow occurs within the specimens.
1.11 It is not practical for a test method of this type to
1.6 Although no definitive upper limit can be given for the
establish details of design and construction and the procedures
magnitude of specimen conductance that is measurable on a
to cover all contingencies that might offer difficulties to a
person without technical knowledge concerning theory of heat
1
This test method is under the jurisdiction of ASTM Committee C-16 on flow, temperature measurements and general testing practices.
Thermal Insulation and is the direct responsibility of Subcommittee C16.30 on
The user may also find it necessary, when repairing or
Thermal Measurement.
modifying the apparatus, to become a designer or builder, or
Current edition approved Feb. 10, 1997. Published June 1997. Originally
both, on whom the demands for fundamental understanding
published as C177–42. Last previous edition C177–85 (1993).
2
The boldface numbers given in parentheses refer to the list of referen
...

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1.1 This practice provides the user with a uniform procedure for calculating the thermal transmission properties of a material or system from data generated by steady state, one dimensional test methods used to determine heat flux and surface temperatures. This practice is intended to eliminate the need for similar calculation sections in Test Methods C177, C335, C518, C1033, C1114 and C1363 and Practices C1043 and C1044 by permitting use of these standard calculation forms by reference.  
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Standard Test Method for Steady-State Thermal Transmission Properties by Means of the Thin-Heater Apparatus

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5.1 Factors that may influence the thermal-transmission properties of a specimen of material are described in Practice C1045 and the Precision and Bias section of Test Method C177.  
5.2 Because of the required test conditions prescribed by this test method, it shall be recognized that the thermal properties obtained will not necessarily apply without modification to all conditions of service. As an example, this test method normally provides that the thermal properties shall be obtained on specimens that do not contain moisture, although in service such conditions may not be realized. Even more basic is the dependence of the thermal properties on variables such as mean temperature and temperature difference.  
5.3 When a new or modified design of apparatus is evolved, tests shall be made on at least two sets of differing material of known long-term thermal stability. Tests shall be made for each material at a minimum of two different mean temperatures within the operating range of each. Any differences in results should be carefully studied to determine the cause and then be removed by appropriate action. Only after a successful verification study on materials having known thermal properties traceable to a recognized national standards laboratory shall test results obtained with this apparatus be considered to conform with this test method. Periodic checks of apparatus performance are recommended.  
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5.5 Typical uses for the thin-heater apparatus include the following:  
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5.5.2 Measurement of thermal conductivity at desired mean temperatures.  
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1.1 This test method covers the determination of the steady-state thermal transmission properties of flat-slab specimens of thermal insulation using a thin heater of uniform power density having low lateral heat flow. A thin heater with low lateral thermal conductance can reduce unwanted lateral heat flow and avoid the need for active-edge guarding.  
1.2 This primary test method of thermal-transmission measurement describes a principle, rather than a particular apparatus. The principle involves determination of the thermal flux across a specimen of known thickness and the temperatures of the hot and cold faces of the specimen.  
1.3 Considerable latitude is given to the designer of the apparatus in this test method; since a variety of designs is possible, a procedure for qualifying an apparatus is given in 5.3.  
1.4 The specimens must meet the following conditions if thermal resistance or thermal conductance of the specimen is to be determined by this test method2:  
1.4.1 The portion of the specimen over the isothermal area of the heater must accurately represent the whole specimen.  
1.4.2 The remainder of the specimen should not distort the heat flow in that part of the specimen defined in 1.4.1.  
1.4.3 The specimen shall be thermally homogeneous such that the thermal conductivity is not a function of the position within the sample, but rather may be a function of direction, time, and temperature. The specimen shall be free of holes, of high-density volumes, and of thermal bridges between the test surfaces or the specimen edges.  
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4.1 This practice describes the design of a guarded hot plate with circular line-heat sources and provides guidance in determining the mean temperature of the meter plate. It provides information and calculation procedures for: (1) control of edge heat loss or gain (Annex A1); (2) location and installation of line-heat sources (Annex A2); (3) design of the gap between the meter and guard plates (Appendix X1); and (4) location of heater leads for the meter plate (Appendix X2).  
4.2 A circular guarded hot plate with one or more line-heat sources is amenable to mathematical analysis so that the mean surface temperature is calculated from the measured power input and the measured temperature(s) at one or more known locations. Further, a circular plate geometry simplifies the mathematical analysis of errors resulting from heat gains or losses at the edges of the specimens (see Refs (10, 11)).  
4.3 The line-heat source(s) is (are) placed in the meter plate at a prescribed radius such that the temperature at the outer edge of the meter plate is equal to the mean surface temperature over the meter area. Thus, the determination of the mean temperature of the meter plate is accomplished with a small number of temperature sensors placed near the gap.  
4.4 A guarded hot plate with one or more line-heat sources will have a radial temperature variation, with the maximum temperature differences being quite small compared to the average temperature drop across the specimens. Provided guarding is adequate, only the mean surface temperature of the meter plate enters into calculations of thermal transmission properties.  
4.5 Care shall be taken to design a circular line-heat-source guarded hot plate so that the electric-current leads to each heater either do not significantly alter the temperature distributions in the meter and guard plates or else affect these temperature distributions in a known way so that appropriate corrections are applied.  
4.6 The use of one or a few ...
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1.1 This practice covers the design of a circular line-heat-source guarded hot plate for use in accordance with Test Method C177.  
Note 1: Test Method C177 describes the guarded-hot-plate apparatus and the application of such equipment for determining thermal transmission properties of flat-slab specimens. In principle, the test method includes apparatus designed with guarded hot plates having either distributed- or line-heat sources.  
1.2 The guarded hot plate with circular line-heat sources is a design in which the meter and guard plates are circular plates having a relatively small number of heaters, each embedded along a circular path at a fixed radius. In operation, the heat from each line-heat source flows radially into the plate and is transmitted axially through the test specimens.  
1.3 The meter and guard plates are fabricated from a continuous piece of thermally conductive material. The plates are made sufficiently thick that, for typical specimen thermal conductances, the radial and axial temperature variations in the guarded hot plate are quite small. By proper location of the line-heat source(s), the temperature at the edge of the meter plate is made equal to the mean temperature of the meter plate, thus facilitating temperature measurements and thermal guarding.  
1.4 The line-heat-source guarded hot plate has been used successfully over a mean temperature range from − 10 to + 65°C, with circular metal plates and a single line-heat source in the meter plate. The chronological development of the design of circular line-heat-source guarded hot plates is given in Refs (1-9).2
Note 2: Detailed drawings and descriptions for the construction of two line-heat-source guarded-hot-plate apparatuses are available in the adjunct.3  
1.5 This practice does not preclude (1) lower or higher temperatures; (2) plate geometries other than circular; (3) line-heat-source geometries other than circular; (4) the use of...

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ASTM
ASTM C177-19e1(Test Method)
Standard Test Method for Steady-State Heat Flux Measurements and Thermal Transmission Properties by Means of the Guarded-Hot-Plate Apparatus

SIGNIFICANCE AND USE
5.1 This test method covers the measurement of heat flux and associated test conditions for flat specimens. The guarded-hot-plate apparatus is generally used to measure steady-state heat flux through materials having a “low” thermal conductivity and commonly denoted as “thermal insulators.” Acceptable measurement accuracy requires a specimen geometry with a large ratio of area to thickness.  
5.2 Two specimens are selected with their thickness, areas, and densities as identical as possible, and one specimen is placed on each side of the guarded-hot-plate. The faces of the specimens opposite the guarded-hot-plate and primary guard are placed in contact with the surfaces of the cold surface assemblies.  
5.3 Steady-state heat transmission through thermal insulators is not easily measured, even at room temperature. This is due to the fact heat transmission through a specimen occurs by any or all of three separate modes of heat transfer (radiation, conduction, and convection). It is possible that any inhomogeneity or anisotropy in the specimen will require special experimental precautions to measure that flow of heat. In some cases it is possible that hours or even days will be required to achieve the thermal steady-state. No guarding system can be constructed to force the metered heat to pass only through the test area of insulation specimen being measured. It is possible that moisture content within the material will cause transient behavior. It is also possible that and physical or chemical change in the material with time or environmental condition will permanently alter the specimen.  
5.4 Application of this test method on different test insulations requires that the designer make choices in the design selection of materials of construction and measurement and control systems. Thus it is possible that there will be different designs for the guarded-hot-plate apparatus when used at ambient versus cryogenic or high temperatures. Test thickness, temperature range,...
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1.1 This test method establishes the criteria for the laboratory measurement of the steady-state heat flux through flat, homogeneous specimen(s) when their surfaces are in contact with solid, parallel boundaries held at constant temperatures using the guarded-hot-plate apparatus.  
1.2 The test apparatus designed for this purpose is known as a guarded-hot-plate apparatus and is a primary (or absolute) method. This test method is comparable, but not identical, to ISO 8302.  
1.3 This test method sets forth the general design requirements necessary to construct and operate a satisfactory guarded-hot-plate apparatus. It covers a wide variety of apparatus constructions, test conditions, and operating conditions. Detailed designs conforming to this test method are not given but must be developed within the constraints of the general requirements. Examples of analysis tools, concepts and procedures used in the design, construction, calibration and operation of a guarded-hot-plate apparatus are given in Refs (1-41).2  
1.4 This test method encompasses both the single-sided and the double-sided modes of measurement. Both distributed and line source guarded heating plate designs are permitted. The user should consult the standard practices on the single-sided mode of operation, Practice C1044, and on the line source apparatus, Practice C1043, for further details on these heater designs.  
1.5 The guarded-hot-plate apparatus can be operated with either vertical or horizontal heat flow. The user is cautioned however, since the test results from the two orientations may be different if convective heat flow occurs within the specimens.  
1.6 Although no definitive upper limit can be given for the magnitude of specimen conductance that is measurable on a guarded-hot-plate, for practical reasons the specimen conductance should be less than 16 W/(m2K).  
1.7 This test method is applicable to the measurement of a wide variety of sp...

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ASTM E473-23b(Terminology)
Standard Terminology Relating to Thermal Analysis and Rheology

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1.1 This terminology is a compilation of definitions of terms used in ASTM documents relating to thermal analysis and rheology. This terminology includes only those terms for which ASTM either has standards or is contemplating some action. It is not intended to be an all-inclusive listing of terms related to thermal analysis and rheology.  
1.2 This terminology specifically supports the single-word form for terms using thermo as a prefix, such as thermoanalytical or thermomagnetometry, while recognizing that for some terms a two-word form can be used, such as thermal analysis. This terminology does not support, nor does it recommend, use of the grammatically incorrect, single-word form using thermal as a prefix, such as, thermalanalytical or thermalmagnetometry.  
1.3 A definition is a single sentence with additional information included in a Discussion area. It is reviewed every five years.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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ASTM E2070-23(Test Method)
Standard Test Methods for Kinetic Parameters by Differential Scanning Calorimetry Using Isothermal Methods

SIGNIFICANCE AND USE
6.1 These test methods are useful for research and development, quality assurance, regulatory compliance, and specification acceptance purposes.  
6.2 The determination of the order of a chemical reaction or transformation at specific temperatures or time conditions is beyond the scope of these test methods.  
6.3 The activation energy results obtained by these test methods may be compared with those obtained from Test Method E698 for nth order and accelerating reactions. Activation energy, pre-exponential factor, and reaction order results by these test methods may be compared to those for Test Method E2041 for nth order reactions.
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1.1 Test Methods A, B, and C determine kinetic parameters for activation energy, pre-exponential factor and reaction order using differential scanning calorimetry (DSC) from a series of isothermal experiments over a small (≈10 K) temperature range. Test Method A is applicable to low nth order reactions. Test Methods B and C are applicable to accelerating reactions such as thermoset curing or pyrotechnic reactions and crystallization transformations in the temperature range from 300 K to 900 K (nominally 30 °C to 630 °C). These test methods are applicable only to these types of exothermic reactions when the thermal curves do not exhibit shoulders, double peaks, discontinuities or shifts in baseline.  
1.2 Test Methods D and E also determines the activation energy of a set of time-to-event and isothermal temperature data generated by this or other procedures  
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.4 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. Specific precautionary statements are given in Section 8.  
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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