ASTM C1044-16(2020)
(Practice)Standard Practice for Using a Guarded-Hot-Plate Apparatus or Thin-Heater Apparatus in the Single-Sided Mode
Standard Practice for Using a Guarded-Hot-Plate Apparatus or Thin-Heater Apparatus in the Single-Sided Mode
SIGNIFICANCE AND USE
4.1 This practice provides a procedure for operating the apparatus so that the heat flow, Q′, through the meter section of the auxiliary insulation is small; determining Q′; and, calculating the heat flow, Q, through the meter section of the specimen.
4.2 This practice requires that the apparatus have independent temperature controls in order to operate the cold plate and auxiliary cold plate at different temperatures. In the single-sides mode, the apparatus is operated with the temperature of the auxiliary cold plate maintained at the same temperature of the hot plate face adjacent to the auxiliary insulation.
Note 4: In principle, if the temperature difference across the auxiliary insulation is zero and there are no edge heat losses or gains, all of the power input to the meter plate will flow through the specimen. In practice, a small correction is made for heat flow, Q′, through the auxiliary insulation.
4.3 The thermal conductance, C’, of the auxiliary insulation shall be determined from one or more separate tests using either Test Method C177, C1114, or as indicated in 5.4. Values of C’ shall be checked periodically, particularly when the temperature drop across the auxiliary insulation less than 1 % of the temperature drop across the test specimen.
4.4 This practice is used when it is desirable to determine the thermal properties of a single specimen. For example, the thermal properties of a single specimen are used to calibrate a heat-flow-meter apparatus for Test Method C518.
SCOPE
1.1 This practice covers the determination of the steady-state heat flow through the meter section of a specimen when a guarded-hot-plate apparatus or thin-heater apparatus is used in the single-sided mode of operation.
1.2 This practice provides a supplemental procedure for use in conjunction with either Test Method C177 or C1114 for testing a single specimen. This practice is limited to only the single-sided mode of operation, and, in all other particulars, the requirements of either Test Method C177 or C1114 apply.
Note 1: Test Methods C177 and C1114 describe the use of the guarded-hot-plate and thin-heater apparatus, respectively, for determining steady-state heat flux and thermal transmission properties of flat-slab specimens. In principle, these methods cover both the double- and single-sided mode of operation, and at present, do not distinguish between the accuracies for the two modes of operation. When appropriate, thermal transmission properties shall be calculated in accordance with Practice C1045.
1.3 This practice requires that the cold plates of the apparatus have independent temperature controls. For the single-sided mode of operation, a (single) specimen is placed between the hot plate and the cold plate. Auxiliary thermal insulation, if needed, is placed between the hot plate and the auxiliary cold plate. The auxiliary cold plate and the hot plate are maintained at the same temperature. The heat flow from the meter plate is assumed to flow only through the specimen, so that the thermal transmission properties correspond only to the specimen.
Note 2: The double-sided mode of operation requires similar specimens placed on either side of the hot plate. The cold plates that contact the outer surfaces of these specimens are maintained at the same temperature. The electric power supplied to the meter plate is assumed to result in equal heat flow through the meter section of each specimen, so that the thermal transmission properties correspond to an average for the two specimens.
1.4 This practice does not preclude the use of a guarded-hot-plate apparatus in which the auxiliary cold plate is either larger or smaller in lateral dimensions than either the test specimen or the cold plate.
Note 3: Most guarded-hot-plate apparatus are designed for the double-sided mode of operation (1).2 Consequently, the cold plate and the auxiliary cold plate are the same size and the spec...
General Information
Relations
Buy Standard
Standards Content (Sample)
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.
Designation: C1044 − 16 (Reapproved 2020)
Standard Practice for
Using a Guarded-Hot-Plate Apparatus or Thin-Heater
Apparatus in the Single-Sided Mode
This standard is issued under the fixed designation C1044; 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.
NOTE3—Mostguarded-hot-plateapparatusaredesignedforthedouble-
1. Scope
sided mode of operation (1). Consequently, the cold plate and the
1.1 This practice covers the determination of the steady-
auxiliary cold plate are the same size and the specimen and the auxiliary
state heat flow through the meter section of a specimen when insulation will have the same lateral dimensions, although the thicknesses
need not be the same. Some guarded-hot-plate apparatus, however, are
a guarded-hot-plate apparatus or thin-heater apparatus is used
designedspecificallyfortestingonlyasinglespecimenthatiseitherlarger
in the single-sided mode of operation.
or smaller in lateral dimensions than the auxiliary insulation or the
1.2 This practice provides a supplemental procedure for use auxiliary cold plate.
in conjunction with either Test Method C177 or C1114 for
1.5 This practice is suitable for use for both low- and
testing a single specimen. This practice is limited to only the
high-temperature conditions.
single-sidedmodeofoperation,and,inallotherparticulars,the
1.6 This practice shall not be used when operating an
requirements of either Test Method C177 or C1114 apply.
apparatus in a double-sided mode of operation with a known
NOTE 1—Test Methods C177 and C1114 describe the use of the
and unknown specimen, that is, with the two cold plates at
guarded-hot-plate and thin-heater apparatus, respectively, for determining
similar temperatures so that the temperature differences across
steady-state heat flux and thermal transmission properties of flat-slab
the known and unknown specimens are similar.
specimens. In principle, these methods cover both the double- and
single-sided mode of operation, and at present, do not distinguish between
1.7 This standard does not purport to address all of the
the accuracies for the two modes of operation. When appropriate, thermal
safety concerns, if any, associated with its use. It is the
transmission properties shall be calculated in accordance with Practice
responsibility of the user of this standard to establish appro-
C1045.
priate safety, health, and environmental practices and deter-
1.3 This practice requires that the cold plates of the appa-
mine the applicability of regulatory limitations prior to use.
ratus have independent temperature controls. For the single-
1.8 This international standard was developed in accor-
sidedmodeofoperation,a(single)specimenisplacedbetween
dance with internationally recognized principles on standard-
the hot plate and the cold plate.Auxiliary thermal insulation, if
ization established in the Decision on Principles for the
needed, is placed between the hot plate and the auxiliary cold
Development of International Standards, Guides and Recom-
plate. The auxiliary cold plate and the hot plate are maintained
mendations issued by the World Trade Organization Technical
at the same temperature. The heat flow from the meter plate is
Barriers to Trade (TBT) Committee.
assumedtoflowonlythroughthespecimen,sothatthethermal
transmission properties correspond only to the specimen.
2. Referenced Documents
NOTE 2—The double-sided mode of operation requires similar speci- 2.1 ASTM Standards:
mensplacedoneithersideofthehotplate.Thecoldplatesthatcontactthe
C168 Terminology Relating to Thermal Insulation
outer surfaces of these specimens are maintained at the same temperature.
C177 Test Method for Steady-State Heat Flux Measure-
Theelectricpowersuppliedtothemeterplateisassumedtoresultinequal
ments and Thermal Transmission Properties by Means of
heat flow through the meter section of each specimen, so that the thermal
the Guarded-Hot-Plate Apparatus
transmission properties correspond to an average for the two specimens.
C518 Test Method for Steady-State Thermal Transmission
1.4 This practice does not preclude the use of a guarded-
Properties by Means of the Heat Flow Meter Apparatus
hot-plate apparatus in which the auxiliary cold plate is either
C1045 Practice for Calculating Thermal Transmission Prop-
larger or smaller in lateral dimensions than either the test
erties Under Steady-State Conditions
specimen or the cold plate.
1 2
This practice is under the jurisdiction of ASTM Committee C16 on Thermal The boldface numbers in parentheses refer to the list of references at the end of
Insulation and is the direct responsibility of Subcommittee C16.30 on Thermal this standard.
Measurement. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Oct. 1, 2020. Published October 2020. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 1985. Last previous edition approved in 2016 as C1044 – 16. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/C1044-16R20. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C1044 − 16 (2020)
C1114 Test Method for Steady-State Thermal Transmission 3.3.8 T —surface temperature of hot plate in contact with
h
Properties by Means of the Thin-Heater Apparatus specimen, K.
3.3.9 T' —surface temperature of hot plate in contact with
h
3. Terminology auxiliary insulation, K.
3.1 Definitions—For definitions of terms used in this
4. Significance and Use
practice, refer to Terminology C168. For definitions of terms
4.1 This practice provides a procedure for operating the
relating to the guarded-hot-plate apparatus or thin-heater ap-
apparatus so that the heat flow, Q', through the meter section of
paratus refer to Test Methods C177 or C1114, respectively,
the auxiliary insulation is small; determining Q'; and, calculat-
3.2 Definitions of Terms Specific to This Standard:
ingtheheatflow, Q,throughthemetersectionofthespecimen.
3.2.1 auxiliary cold plate, n—the plate that provides an
4.2 This practice requires that the apparatus have indepen-
isothermal boundary at the outside surface of the auxiliary
dent temperature controls in order to operate the cold plate and
insulation.
auxiliary cold plate at different temperatures. In the single-
3.2.2 auxiliary insulation, n—thermal insulation used in
sides mode, the apparatus is operated with the temperature of
placeofasecondtestspecimen,whenthesingle-sidedmodeof
the auxiliary cold plate maintained at the same temperature of
operation is used (syn. dummy specimen).
the hot plate face adjacent to the auxiliary insulation.
3.2.3 cold plate, n—the plate that provides an isothermal
NOTE 4—In principle, if the temperature difference across the auxiliary
boundary at the cold surface of the specimen.
insulation is zero and there are no edge heat losses or gains, all of the
3.2.4 double-sided mode, n—operation of the apparatus, power input to the meter plate will flow through the specimen. In practice,
a small correction is made for heat flow, Q', through the auxiliary
suchthattheheatinputtothemeterplateflowsequallythrough
insulation.
two specimens, each specimen placed on either side of the hot
plate (see also single-sided mode). 4.3 The thermal conductance, C’, of the auxiliary insulation
shall be determined from one or more separate tests using
3.2.5 gap, n—separation between the meter plate and guard
either Test Method C177, C1114, or as indicated in 5.4. Values
plate, usually filled with a gas or thermal insulation.
of C’ shall be checked periodically, particularly when the
3.2.6 guard plate, n—the outer (rectangular or circular) ring
temperature drop across the auxiliary insulation less than 1 %
of the guarded hot plate, that encompasses the meter plate and
of the temperature drop across the test specimen.
promotes one-dimensional heat flow normal to the meter plate.
4.4 This practice is used when it is desirable to determine
3.2.7 guarded hot plate, n—an assembly, consisting of a
the thermal properties of a single specimen. For example, the
meter plate and a co-planar, concentric guard plate, that
thermal properties of a single specimen are used to calibrate a
provides the heat input to the specimen(s).
heat-flow-meter apparatus for Test Method C518.
3.2.8 meterplate,n—theinner(rectangularorcircular)plate
of the guarded hot plate, that provides the heat input to the 5. Procedure for Single-Sided Mode of Operation
meter section of the specimen(s).
5.1 Refer to Fig. 1 for a schematic diagram of the single-
3.2.9 meter section, n—the portion of the specimen (or
sided mode of operation of the guarded-hot-plate apparatus.
auxiliary insulation) through which the heat input to the meter
NOTE 5—The schematic diagram for a thin-heater apparatus (not
plate flows under ideal guarding conditions.
shown) is similar, except the hot plate is much thinner and is not
partitioned by a gap.
3.2.10 single-sided mode, n—operation of the apparatus
such that essentially all of the heat input to the meter plate
5.2 Follow the procedure of either Test Method C177 or
flows through a specimen placed on one side of the hot plate
C1114 with the following modifications.
(see also double-sided mode).
5.3 Select a rigid or semi-rigid material for the auxiliary
3.2.11 thin heater, n—an assembly, consisting of an unpar-
insulation having a low thermal conductance so that heat gains
titioned thin-screen heater or thin-foil, that provides the heat
or losses from the face of the meter plate in contact with the
input to the specimen(s).
auxiliary insulation will be small. The thickness and lateral
conductance of the auxiliary insulation shall be small to avoid
3.3 Symbols—The symbols used in this practice have the
significanteffectsontheheattransferthroughthemetersection
following significance. The prime (') denotes quantities asso-
oftheauxiliaryinsulationduetoheattransferattheedgeofthe
ciated with the auxiliary insulation used to control heat from
auxiliary insulation.
the other side of the hot plate.
3.3.1 A—meter area of hot plate, m .
NOTE 6—The influence of edge effects for a particular apparatus and
3.3.2 C'—thermal conductance of auxiliary insulation,
test configuration is determined experimentally as described in Test
Method C177 or by computation using one of the procedures referenced
W/(m • K).
in Test Method C177 or described by Peavy and Rennex (2).
3.3.3 Q—heat flow through meter section of specimen, W.
3.3.4 Q'—heat flow through meter section of auxiliary 5.4 Determine C’ of the auxiliary insulation over the tem-
insulation, W.
perature range of interest using one of the following proce-
3.3.5 Q —power input to meter plate, W. dures: (1) Test Method C177 or C1114 in a separate test setup
m
3.3.6 T —surface temperature of cold plate, K.
for a matched pair of similar specimens; or (2) in-situ as
c
3.3.7 T' —surface temperature of auxiliary cold plate, K. described in Annex A1.
c
C1044 − 16 (2020)
FIG. 1 Diagram Illustrating Single-Sided Mode of Operation of the Guarded-Hot-Plate Apparatus
5.4.1 In the first instance, using either Test Method C177 or 5.8 Establish thermal steady-state conditions in accordance
C1114, a matched pair of similar specimens is required so that with either Test Method C177 or C1114.
either single specimen subsequently is suitable for use as the
5.9 Acquire the required test data and determine A, Q ,T ,
m h
auxiliary insulation.
T' , and T' in accordance with either Test Method C177 or
h c
5.4.2 In the second instance using in-situ as described in
C1114.
Annex A1, successive tests are required, one with a small
temperature difference across the test specimen and one with a
6. Calculation
small temperature difference across the auxiliary insulation.
6.1 Calculate the heat flow through the auxiliary insulation
NOTE 7—In 5.4 the user is not required to determine values for C’ for
as follows:
every test that will be conducted. Rather, determine C’as a function of
Q' 5 C' A ~T' 2 T' ! (1)
temperature over the temperature range of interest so that a corresponding h c
where:
regression curve is developed for subsequent testing.
5.5 When using a compressible material as the auxiliary
C’is the thermal conductance of the auxiliary insulation at a
insulation, determine C’either at the same thickness as that
temperature corresponding to (T' +T' )/2, as obtained accord-
h c
usedinthesingle-sidedmodeofoperationorcompressedto(at
ing to 5.4.
least) two slightly different thicknesses, thus allowing interpo-
6.2 Calculatetheheatflowthroughthespecimenasfollows:
lation for the thickness actually used in the single-sided mode
Q 5 Q 2 Q' (2)
of operation. m
5.5.1 For an apparatus without a separate provision for
6.3 Use the value of Q, thus obtained to calculate steady-
determiningtheindividualthicknessesofthetwospecimenson
statethermaltransmissionproperties,inaccordancewitheither
opposite sides of the hot plate, place three or more low-
Test Method C177 or C1114. When appropriate, consult
conductance rigid spacers near the outer periphery of the guard
Practice C1045 to calculate steady-state thermal transmission
platebetweenthehotplateandthesurfaceoftheauxiliarycold
properties. For reference, calculation equations are provided in
plate.
Appendix X1.
5.5.2 Compute the effective thickness of the test specimen
by subtracting the thickness of the rigid spacers (corrected for 7. Sources of Experimental Error
thermal expansion, if necessary) from the thickness that is
7.1 Errors in the determination of Q, are introduced from
determined for the test specimen plus the auxiliary insulation.
several sources, including measurement of the power input Q
m
In this case, the separate tests of thermal conductance accord-
to the meter plate; estimation of the heat flow, Q', through the
ing to 5.4.2 shall be conducted with rigid spacers.
auxiliary insulation and, for guarded hot plates, estimation of
5.6 Maintain the cold plate at the required temperature T . the heat flow across the gap between the meter plate and guard
c
Provide power input to the hot plate to attain the required plate, that is, gap error.
temperature T on the hot side of the test specimen.
h
7.2 Refer to either Test Method C177 or C1114 for discus-
5.7 Maintain the temper
...
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: C1044 − 16 (Reapproved 2020)
Standard Practice for
Using a Guarded-Hot-Plate Apparatus or Thin-Heater
Apparatus in the Single-Sided Mode
This standard is issued under the fixed designation C1044; 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.
NOTE 3—Most guarded-hot-plate apparatus are designed for the double-
1. Scope
sided mode of operation (1). Consequently, the cold plate and the
1.1 This practice covers the determination of the steady-
auxiliary cold plate are the same size and the specimen and the auxiliary
state heat flow through the meter section of a specimen when
insulation will have the same lateral dimensions, although the thicknesses
need not be the same. Some guarded-hot-plate apparatus, however, are
a guarded-hot-plate apparatus or thin-heater apparatus is used
designed specifically for testing only a single specimen that is either larger
in the single-sided mode of operation.
or smaller in lateral dimensions than the auxiliary insulation or the
1.2 This practice provides a supplemental procedure for use auxiliary cold plate.
in conjunction with either Test Method C177 or C1114 for
1.5 This practice is suitable for use for both low- and
testing a single specimen. This practice is limited to only the
high-temperature conditions.
single-sided mode of operation, and, in all other particulars, the
1.6 This practice shall not be used when operating an
requirements of either Test Method C177 or C1114 apply.
apparatus in a double-sided mode of operation with a known
NOTE 1—Test Methods C177 and C1114 describe the use of the
and unknown specimen, that is, with the two cold plates at
guarded-hot-plate and thin-heater apparatus, respectively, for determining
similar temperatures so that the temperature differences across
steady-state heat flux and thermal transmission properties of flat-slab
the known and unknown specimens are similar.
specimens. In principle, these methods cover both the double- and
single-sided mode of operation, and at present, do not distinguish between
1.7 This standard does not purport to address all of the
the accuracies for the two modes of operation. When appropriate, thermal
safety concerns, if any, associated with its use. It is the
transmission properties shall be calculated in accordance with Practice
responsibility of the user of this standard to establish appro-
C1045.
priate safety, health, and environmental practices and deter-
1.3 This practice requires that the cold plates of the appa-
mine the applicability of regulatory limitations prior to use.
ratus have independent temperature controls. For the single-
1.8 This international standard was developed in accor-
sided mode of operation, a (single) specimen is placed between
dance with internationally recognized principles on standard-
the hot plate and the cold plate. Auxiliary thermal insulation, if
ization established in the Decision on Principles for the
needed, is placed between the hot plate and the auxiliary cold
Development of International Standards, Guides and Recom-
plate. The auxiliary cold plate and the hot plate are maintained
mendations issued by the World Trade Organization Technical
at the same temperature. The heat flow from the meter plate is
Barriers to Trade (TBT) Committee.
assumed to flow only through the specimen, so that the thermal
transmission properties correspond only to the specimen.
2. Referenced Documents
NOTE 2—The double-sided mode of operation requires similar speci- 2.1 ASTM Standards:
mens placed on either side of the hot plate. The cold plates that contact the
C168 Terminology Relating to Thermal Insulation
outer surfaces of these specimens are maintained at the same temperature.
C177 Test Method for Steady-State Heat Flux Measure-
The electric power supplied to the meter plate is assumed to result in equal
ments and Thermal Transmission Properties by Means of
heat flow through the meter section of each specimen, so that the thermal
the Guarded-Hot-Plate Apparatus
transmission properties correspond to an average for the two specimens.
C518 Test Method for Steady-State Thermal Transmission
1.4 This practice does not preclude the use of a guarded-
Properties by Means of the Heat Flow Meter Apparatus
hot-plate apparatus in which the auxiliary cold plate is either
C1045 Practice for Calculating Thermal Transmission Prop-
larger or smaller in lateral dimensions than either the test
erties Under Steady-State Conditions
specimen or the cold plate.
1 2
This practice is under the jurisdiction of ASTM Committee C16 on Thermal The boldface numbers in parentheses refer to the list of references at the end of
Insulation and is the direct responsibility of Subcommittee C16.30 on Thermal this standard.
Measurement. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Oct. 1, 2020. Published October 2020. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 1985. Last previous edition approved in 2016 as C1044 – 16. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/C1044-16R20. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C1044 − 16 (2020)
C1114 Test Method for Steady-State Thermal Transmission 3.3.8 T —surface temperature of hot plate in contact with
h
Properties by Means of the Thin-Heater Apparatus specimen, K.
3.3.9 T' —surface temperature of hot plate in contact with
h
auxiliary insulation, K.
3. Terminology
3.1 Definitions—For definitions of terms used in this
4. Significance and Use
practice, refer to Terminology C168. For definitions of terms
4.1 This practice provides a procedure for operating the
relating to the guarded-hot-plate apparatus or thin-heater ap-
apparatus so that the heat flow, Q', through the meter section of
paratus refer to Test Methods C177 or C1114, respectively,
the auxiliary insulation is small; determining Q'; and, calculat-
3.2 Definitions of Terms Specific to This Standard:
ing the heat flow, Q, through the meter section of the specimen.
3.2.1 auxiliary cold plate, n—the plate that provides an
4.2 This practice requires that the apparatus have indepen-
isothermal boundary at the outside surface of the auxiliary
dent temperature controls in order to operate the cold plate and
insulation.
auxiliary cold plate at different temperatures. In the single-
3.2.2 auxiliary insulation, n—thermal insulation used in
sides mode, the apparatus is operated with the temperature of
place of a second test specimen, when the single-sided mode of
the auxiliary cold plate maintained at the same temperature of
operation is used (syn. dummy specimen).
the hot plate face adjacent to the auxiliary insulation.
3.2.3 cold plate, n—the plate that provides an isothermal
NOTE 4—In principle, if the temperature difference across the auxiliary
boundary at the cold surface of the specimen.
insulation is zero and there are no edge heat losses or gains, all of the
3.2.4 double-sided mode, n—operation of the apparatus, power input to the meter plate will flow through the specimen. In practice,
a small correction is made for heat flow, Q', through the auxiliary
such that the heat input to the meter plate flows equally through
insulation.
two specimens, each specimen placed on either side of the hot
4.3 The thermal conductance, C’, of the auxiliary insulation
plate (see also single-sided mode).
shall be determined from one or more separate tests using
3.2.5 gap, n—separation between the meter plate and guard
either Test Method C177, C1114, or as indicated in 5.4. Values
plate, usually filled with a gas or thermal insulation.
of C’ shall be checked periodically, particularly when the
3.2.6 guard plate, n—the outer (rectangular or circular) ring
temperature drop across the auxiliary insulation less than 1 %
of the guarded hot plate, that encompasses the meter plate and
of the temperature drop across the test specimen.
promotes one-dimensional heat flow normal to the meter plate.
4.4 This practice is used when it is desirable to determine
3.2.7 guarded hot plate, n—an assembly, consisting of a
the thermal properties of a single specimen. For example, the
meter plate and a co-planar, concentric guard plate, that
thermal properties of a single specimen are used to calibrate a
provides the heat input to the specimen(s).
heat-flow-meter apparatus for Test Method C518.
3.2.8 meter plate, n—the inner (rectangular or circular) plate
of the guarded hot plate, that provides the heat input to the 5. Procedure for Single-Sided Mode of Operation
meter section of the specimen(s).
5.1 Refer to Fig. 1 for a schematic diagram of the single-
3.2.9 meter section, n—the portion of the specimen (or
sided mode of operation of the guarded-hot-plate apparatus.
auxiliary insulation) through which the heat input to the meter
NOTE 5—The schematic diagram for a thin-heater apparatus (not
plate flows under ideal guarding conditions.
shown) is similar, except the hot plate is much thinner and is not
partitioned by a gap.
3.2.10 single-sided mode, n—operation of the apparatus
such that essentially all of the heat input to the meter plate
5.2 Follow the procedure of either Test Method C177 or
flows through a specimen placed on one side of the hot plate
C1114 with the following modifications.
(see also double-sided mode).
5.3 Select a rigid or semi-rigid material for the auxiliary
3.2.11 thin heater, n—an assembly, consisting of an unpar-
insulation having a low thermal conductance so that heat gains
titioned thin-screen heater or thin-foil, that provides the heat
or losses from the face of the meter plate in contact with the
input to the specimen(s).
auxiliary insulation will be small. The thickness and lateral
conductance of the auxiliary insulation shall be small to avoid
3.3 Symbols—The symbols used in this practice have the
significant effects on the heat transfer through the meter section
following significance. The prime (') denotes quantities asso-
of the auxiliary insulation due to heat transfer at the edge of the
ciated with the auxiliary insulation used to control heat from
auxiliary insulation.
the other side of the hot plate.
3.3.1 A—meter area of hot plate, m .
NOTE 6—The influence of edge effects for a particular apparatus and
3.3.2 C'—thermal conductance of auxiliary insulation,
test configuration is determined experimentally as described in Test
W/(m • K). Method C177 or by computation using one of the procedures referenced
in Test Method C177 or described by Peavy and Rennex (2).
3.3.3 Q—heat flow through meter section of specimen, W.
3.3.4 Q'—heat flow through meter section of auxiliary
5.4 Determine C’ of the auxiliary insulation over the tem-
insulation, W. perature range of interest using one of the following proce-
3.3.5 Q —power input to meter plate, W.
dures: (1) Test Method C177 or C1114 in a separate test setup
m
3.3.6 T —surface temperature of cold plate, K. for a matched pair of similar specimens; or (2) in-situ as
c
3.3.7 T' —surface temperature of auxiliary cold plate, K. described in Annex A1.
c
C1044 − 16 (2020)
FIG. 1 Diagram Illustrating Single-Sided Mode of Operation of the Guarded-Hot-Plate Apparatus
5.4.1 In the first instance, using either Test Method C177 or 5.8 Establish thermal steady-state conditions in accordance
C1114, a matched pair of similar specimens is required so that with either Test Method C177 or C1114.
either single specimen subsequently is suitable for use as the
5.9 Acquire the required test data and determine A, Q , T ,
m h
auxiliary insulation.
T' , and T' in accordance with either Test Method C177 or
h c
5.4.2 In the second instance using in-situ as described in
C1114.
Annex A1, successive tests are required, one with a small
temperature difference across the test specimen and one with a
6. Calculation
small temperature difference across the auxiliary insulation.
6.1 Calculate the heat flow through the auxiliary insulation
NOTE 7—In 5.4 the user is not required to determine values for C’ for
as follows:
every test that will be conducted. Rather, determine C’as a function of
Q' 5 C' A T' 2 T' (1)
~ !
temperature over the temperature range of interest so that a corresponding
h c
where:
regression curve is developed for subsequent testing.
5.5 When using a compressible material as the auxiliary
C’is the thermal conductance of the auxiliary insulation at a
insulation, determine C’either at the same thickness as that
temperature corresponding to (T' + T' )/2, as obtained accord-
h c
used in the single-sided mode of operation or compressed to (at
ing to 5.4.
least) two slightly different thicknesses, thus allowing interpo-
6.2 Calculate the heat flow through the specimen as follows:
lation for the thickness actually used in the single-sided mode
Q 5 Q 2 Q' (2)
m
of operation.
5.5.1 For an apparatus without a separate provision for
6.3 Use the value of Q, thus obtained to calculate steady-
determining the individual thicknesses of the two specimens on
state thermal transmission properties, in accordance with either
opposite sides of the hot plate, place three or more low-
Test Method C177 or C1114. When appropriate, consult
conductance rigid spacers near the outer periphery of the guard
Practice C1045 to calculate steady-state thermal transmission
plate between the hot plate and the surface of the auxiliary cold
properties. For reference, calculation equations are provided in
plate.
Appendix X1.
5.5.2 Compute the effective thickness of the test specimen
by subtracting the thickness of the rigid spacers (corrected for 7. Sources of Experimental Error
thermal expansion, if necessary) from the thickness that is
7.1 Errors in the determination of Q, are introduced from
determined for the test specimen plus the auxiliary insulation.
several sources, including measurement of the power input Q
m
In this case, the separate tests of thermal conductance accord-
to the meter plate; estimation of the heat flow, Q', through the
ing to 5.4.2 shall be conducted with rigid spacers.
auxiliary insulation and, for guarded hot plates, estimation of
5.6 Maintain the cold plate at the required temperature T . the heat flow across the gap between the meter plate and guard
c
Provide power input to the hot plate to attain the required plate, that is, gap error.
temperature T on the hot side of the test specimen.
h
7.2 Refer to eithe
...
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: C1044 − 16 C1044 − 16 (Reapproved 2020)
Standard Practice for
Using a Guarded-Hot-Plate Apparatus or Thin-Heater
Apparatus in the Single-Sided Mode
This standard is issued under the fixed designation C1044; 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.
1. Scope
1.1 This practice covers the determination of the steady-state heat flow through the meter section of a specimen when a
guarded-hot-plate apparatus or thin-heater apparatus is used in the single-sided mode of operation.
1.2 This practice provides a supplemental procedure for use in conjunction with either Test Method C177 or C1114 for testing a
single specimen. This practice is limited to only the single-sided mode of operation, and, in all other particulars, the requirements
of either Test Method C177 or C1114 apply.
NOTE 1—Test Methods C177 and C1114 describe the use of the guarded-hot-plate and thin-heater apparatus, respectively, for determining steady-state
heat flux and thermal transmission properties of flat-slab specimens. In principle, these methods cover both the double- and single-sided mode of
operation, and at present, do not distinguish between the accuracies for the two modes of operation. When appropriate, thermal transmission properties
shall be calculated in accordance with Practice C1045.
1.3 This practice requires that the cold plates of the apparatus have independent temperature controls. For the single-sided mode
of operation, a (single) specimen is placed between the hot plate and the cold plate. Auxiliary thermal insulation, if needed, is
placed between the hot plate and the auxiliary cold plate. The auxiliary cold plate and the hot plate are maintained at the same
temperature. The heat flow from the meter plate is assumed to flow only through the specimen, so that the thermal transmission
properties correspond only to the specimen.
NOTE 2—The double-sided mode of operation requires similar specimens placed on either side of the hot plate. The cold plates that contact the outer
surfaces of these specimens are maintained at the same temperature. The electric power supplied to the meter plate is assumed to result in equal heat flow
through the meter section of each specimen, so that the thermal transmission properties correspond to an average for the two specimens.
1.4 This practice does not preclude the use of a guarded-hot-plate apparatus in which the auxiliary cold plate is either larger or
smaller in lateral dimensions than either the test specimen or the cold plate.
NOTE 3—Most guarded-hot-plate apparatus are designed for the double-sided mode of operation (1). Consequently, the cold plate and the auxiliary cold
plate are the same size and the specimen and the auxiliary insulation will have the same lateral dimensions, although the thicknesses need not be the same.
Some guarded-hot-plate apparatus, however, are designed specifically for testing only a single specimen that is either larger or smaller in lateral
dimensions than the auxiliary insulation or the auxiliary cold plate.
1.5 This practice is suitable for use for both low- and high-temperature conditions.
This practice is under the jurisdiction of ASTM Committee C16 on Thermal Insulation and is the direct responsibility of Subcommittee C16.30 on Thermal Measurement.
Current edition approved Sept. 1, 2016Oct. 1, 2020. Published September 2016October 2020. Originally approved in 1985. Last previous edition approved in 20122016
as C1044 – 12.C1044 – 16. DOI: 10.1520/C1044-16.10.1520/C1044-16R20.
The boldface numbers in parentheses refer to the list of references at the end of this standard.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C1044 − 16 (2020)
1.6 This practice shall not be used when operating an apparatus in a double-sided mode of operation with a known and unknown
specimen, that is, with the two cold plates at similar temperatures so that the temperature differences across the known and
unknown specimens are similar.
1.7 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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.8 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.
2. Referenced Documents
2.1 ASTM Standards:
C168 Terminology Relating to Thermal Insulation
C177 Test Method for Steady-State Heat Flux Measurements and Thermal Transmission Properties by Means of the
Guarded-Hot-Plate Apparatus
C518 Test Method for Steady-State Thermal Transmission Properties by Means of the Heat Flow Meter Apparatus
C1045 Practice for Calculating Thermal Transmission Properties Under Steady-State Conditions
C1114 Test Method for Steady-State Thermal Transmission Properties by Means of the Thin-Heater Apparatus
3. Terminology
3.1 Definitions—For definitions of terms used in this practice, refer to Terminology C168. For definitions of terms relating to the
guarded-hot-plate apparatus or thin-heater apparatus refer to Test Methods C177 or C1114, respectively,
3.2 Definitions of Terms Specific to This Standard:
3.2.1 auxiliary cold plate, n—the plate that provides an isothermal boundary at the outside surface of the auxiliary insulation.
3.2.2 auxiliary insulation, n—thermal insulation used in place of a second test specimen, when the single-sided mode of operation
is used (syn. dummy specimen).
3.2.3 cold plate, n—the plate that provides an isothermal boundary at the cold surface of the specimen.
3.2.4 double-sided mode, n—operation of the apparatus, such that the heat input to the meter plate flows equally through two
specimens, each specimen placed on either side of the hot plate (see also single-sided mode).
3.2.5 gap, n—separation between the meter plate and guard plate, usually filled with a gas or thermal insulation.
3.2.6 guard plate, n—the outer (rectangular or circular) ring of the guarded hot plate, that encompasses the meter plate and
promotes one-dimensional heat flow normal to the meter plate.
3.2.7 guarded hot plate, n—an assembly, consisting of a meter plate and a co-planar, concentric guard plate, that provides the heat
input to the specimen(s).
3.2.8 meter plate, n—the inner (rectangular or circular) plate of the guarded hot plate, that provides the heat input to the meter
section of the specimen(s).
3.2.9 meter section, n—the portion of the specimen (or auxiliary insulation) through which the heat input to the meter plate flows
under ideal guarding conditions.
3.2.10 single-sided mode, n—operation of the apparatus such that essentially all of the heat input to the meter plate flows through
a specimen placed on one side of the hot plate (see also double-sided mode).
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
C1044 − 16 (2020)
3.2.11 thin heater, n—an assembly, consisting of an unpartitioned thin-screen heater or thin-foil, that provides the heat input to the
specimen(s).
3.3 Symbols—The symbols used in this practice have the following significance. The prime (') denotes quantities associated with
the auxiliary insulation used to control heat from the other side of the hot plate.
3.3.1 A—meter area of hot plate, m .
3.3.2 C'—thermal conductance of auxiliary insulation, W/(m • K).
3.3.3 Q—heat flow through meter section of specimen, W.
3.3.4 Q'—heat flow through meter section of auxiliary insulation, W.
3.3.5 Q —power input to meter plate, W.
m
3.3.6 T —surface temperature of cold plate, K.
c
3.3.7 T' —surface temperature of auxiliary cold plate, K.
c
3.3.8 T —surface temperature of hot plate in contact with specimen, K.
h
3.3.9 T' —surface temperature of hot plate in contact with auxiliary insulation, K.
h
4. Significance and Use
4.1 This practice provides a procedure for operating the apparatus so that the heat flow, Q', through the meter section of the
auxiliary insulation is small; determining Q'; and, calculating the heat flow, Q, through the meter section of the specimen.
4.2 This practice requires that the apparatus have independent temperature controls in order to operate the cold plate and auxiliary
cold plate at different temperatures. In the single-sides mode, the apparatus is operated with the temperature of the auxiliary cold
plate maintained at the same temperature of the hot plate face adjacent to the auxiliary insulation.
NOTE 4—In principle, if the temperature difference across the auxiliary insulation is zero and there are no edge heat losses or gains, all of the power input
to the meter plate will flow through the specimen. In practice, a small correction is made for heat flow, Q', through the auxiliary insulation.
4.3 The thermal conductance, C’, of the auxiliary insulation shall be determined from one or more separate tests using either Test
Method C177, C1114, or as indicated in 5.4. Values of C’ shall be checked periodically, particularly when the temperature drop
across the auxiliary insulation less than 1 % of the temperature drop across the test specimen.
4.4 This practice is used when it is desirable to determine the thermal properties of a single specimen. For example, the thermal
properties of a single specimen are used to calibrate a heat-flow-meter apparatus for Test Method C518.
5. Procedure for Single-Sided Mode of Operation
5.1 Refer to Fig. 1 for a schematic diagram of the single-sided mode of operation of the guarded-hot-plate apparatus.
NOTE 5—The schematic diagram for a thin-heater apparatus (not shown) is similar, except the hot plate is much thinner and is not partitioned by a gap.
5.2 Follow the procedure of either Test Method C177 or C1114 with the following modifications.
5.3 Select a rigid or semi-rigid material for the auxiliary insulation having a low thermal conductance so that heat gains or losses
from the face of the meter plate in contact with the auxiliary insulation will be small. The thickness and lateral conductance of
the auxiliary insulation shall be small to avoid significant effects on the heat transfer through the meter section of the auxiliary
insulation due to heat transfer at the edge of the auxiliary insulation.
C1044 − 16 (2020)
FIG. 1 Diagram Illustrating Single-Sided Mode of Operation of the Guarded-Hot-Plate Apparatus
NOTE 6—The influence of edge effects for a particular apparatus and test configuration is determined experimentally as described in Test Method C177
or by computation using one of the procedures referenced in Test Method C177 or described by Peavy and Rennex (2).
5.4 Determine C’ of the auxiliary insulation over the temperature range of interest using one of the following procedures: (1) Test
Method C177 or C1114 in a separate test setup for a matched pair of similar specimens; or (2) in-situ as described in Annex A1.
5.4.1 In the first instance, using either Test Method C177 or C1114, a matched pair of similar specimens is required so that either
single specimen subsequently is suitable for use as the auxiliary insulation.
5.4.2 In the second instance using in-situ as described in Annex A1, successive tests are required, one with a small temperature
difference across the test specimen and one with a small temperature difference across the auxiliary insulation.
NOTE 7—In 5.4 the user is not required to determine values for C’ for every test that will be conducted. Rather, determine C’as a function of temperature
over the temperature range of interest so that a corresponding regression curve is developed for subsequent testing.
5.5 When using a compressible material as the auxiliary insulation, determine C’either at the same thickness as that used in the
single-sided mode of operation or compressed to (at least) two slightly different thicknesses, thus allowing interpolation for the
thickness actually used in the single-sided mode of operation.
5.5.1 For an apparatus without a separate provision for determining the individual thicknesses of the two specimens on opposite
sides of the hot plate, place three or more low-conductance rigid spacers near the outer periphery of the guard plate between the
hot plate and the surface of the auxiliary cold plate.
5.5.2 Compute the effective thickness of the test specimen by subtracting the thickness of the rigid spacers (corrected for thermal
expansion, if necessary) from the thickness that is determined for the test specimen plus the auxiliary insulation. In this case, the
separate tests of thermal conductance according to 5.4.2 shall be conducted with rigid spacers.
5.6 Maintain the cold plate at the required temperature T . Provide power input to the hot plate to attain the required temperature
c
T on the hot side of the test specimen.
h
5.7 Maintain the temperature T' as closely as practical to the temperature T' .
c h
5.8 Establish thermal steady-state conditions in accordance with either Test Method C177 or C1114.
C1044 − 16 (2020)
5.9 Acquire the required test data and determine A, Q , T , T' , and T' in accordance with either Test Method C177 or C1114.
m h h c
6. Calculation
6.1 Calculate the heat flow through the auxiliary insulation as follows:
Q'5 C' A ~T' 2 T' ! (1)
h c
where:
C’is the thermal conductance of the auxiliary insulation at a temperature corresponding to (T' + T' )/2, as obtained according
h c
to 5.4.
6.2 Calculate the heat flow through the specimen as follows:
Q 5 Q 2 Q' (2)
m
6.3 Use the value of Q, thus obtained to calculate steady-state thermal transmission properties, in accordance with either Test
Method C177 or C1114. When appropriate, consult Practice C104
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.