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ASTM E459-05

(Test Method)

Standard Test Method for Measuring Heat Transfer Rate Using a Thin-Skin Calorimeter

Standard Test Method for Measuring Heat Transfer Rate Using a Thin-Skin Calorimeter

SIGNIFICANCE AND USE
This test method may be used to measure the heat transfer rate to a metallic or coated metallic surface for a variety of applications, including:
3.1.1 Measurements of aerodynamic heating when the calorimeter is placed into a flow environment, such as a wind tunnel or an arc jet; the calorimeters can be designed to have the same size and shape as the actual test specimens to minimize heat transfer corrections;
3.1.2 Heat transfer measurements in fires and fire safety testing;
3.1.3 Laser power and laser absorption measurements; as well as,
3.1.4 X-ray and particle beam (electrons or ions) dosimetry measurements.
The thin-skin calorimeter is one of many concepts used to measure heat transfer rates. It may be used to measure convective, radiative, or combinations of convective and radiative (usually called mixed or total) heat transfer rates. However, when the calorimeter is used to measure radiative or mixed heat transfer rates, the absorptivity and reflectivity of the surface should be measured over the expected radiation wavelength region of the source.
In 4.6 and 4.7, it is demonstrated that lateral heat conduction effects on a local measurement can be minimized by using a calorimeter material with a low thermal conductivity. Alternatively, a distribution of the heat transfer rate may be obtained by placing a number of thermocouples along the back surface of the calorimeter.
In high temperature or high heat transfer rate applications, the principal drawback to the use of thin-skin calorimeters is the short exposure time necessary to ensure survival of the calorimeter such that repeat measurements can be made with the same sensor. When operation to burnout is necessary to obtain the desired heat flux measurements, thin-skin calorimeters are often a good choice because they are relatively inexpensive to fabricate.
FIG. 1 Typical Thin-Skin Calorimeter for Heat Transfer Measurement
SCOPE
1.1 This test method covers the design and use of a thin metallic calorimeter for measuring heat transfer rate (also called heat flux). Thermocouples are attached to the unexposed surface of the calorimeter. A one-dimensional heat flow analysis is used for calculating the heat transfer rate from the temperature measurements. Applications include aerodynamic heating, laser and radiation power measurements, and fire safety testing.
1.2 Advantages
1.2.1 Simplicity of ConstructionThe calorimeter may be constructed from a number of materials. The size and shape can often be made to match the actual application. Thermocouples may be attached to the metal by spot, electron beam, or laser welding.
1.2.2 Heat transfer rate distributions may be obtained if metals with low thermal conductivity, such as some stainless steels, are used.
1.2.3 The calorimeters can be fabricated with smooth surfaces, without insulators or plugs and the attendant temperature discontinuities, to provide more realistic flow conditions for aerodynamic heating measurements.
1.2.4 The calorimeters described in this test method are relatively inexpensive. If necessary, they may be operated to burn-out to obtain heat transfer information.
1.3 Limitations
1.3.1 At higher heat flux levels, short test times are necessary to ensure calorimeter survival.
1.3.2 For applications in wind tunnels or arc-jet facilities, the calorimeter must be operated at pressures and temperatures such that the thin-skin does not distort under pressure loads. Distortion of the surface will introduce measurement errors.
1.4 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.5 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
14-Sep-2005
ICS
17.200.10 - Heat. Calorimetry
Technical Committee
E21 - Space Simulation and Applications of Space Technology
Drafting Committee
E21.08 - Thermal Protection
Current Stage
Ref Project

Relations

Replaces
ASTM E459-97 - Standard Test Method for Measuring Heat Transfer Rate Using a Thin-Skin Calorimeter
Effective Date
15-Sep-2005
Replaced By
ASTM E459-05(2011) - Standard Test Method for Measuring Heat Transfer Rate Using a Thin-Skin Calorimeter
Effective Date
01-Oct-2011
Referred By
ASTM E3057-19 - Standard Test Method for Measuring Heat Flux Using Directional Flame Thermometers with Advanced Data Analysis Techniques
Effective Date
15-Sep-2005
Referred By
ASTM E457-08(2020) - Standard Test Method for Measuring Heat-Transfer Rate Using a Thermal Capacitance (Slug) Calorimeter
Effective Date
15-Sep-2005
Referred By
ASTM E458-08(2020) - Standard Test Method for Heat of Ablation
Effective Date
15-Sep-2005
Referred By
ASTM E1529-22 - Standard Test Methods for Determining Effects of Large Hydrocarbon Pool Fires on Structural Members and Assemblies
Effective Date
15-Sep-2005
Referred By
ASTM E637-22 - Standard Test Method for Calculation of Stagnation Enthalpy from Heat Transfer Theory and Experimental Measurements of Stagnation-Point Heat Transfer and Pressure
Effective Date
15-Sep-2005
Referred By
ASTM E422-22 - Standard Test Method for Measuring Net Heat Flux Using a Water-Cooled Calorimeter
Effective Date
15-Sep-2005

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ASTM E459-05 - Standard Test Method for Measuring Heat Transfer Rate Using a Thin-Skin CalorimeterASTM E459-05 - Standard Test Method for Measuring Heat Transfer Rate Using a Thin-Skin Calorimeter
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ASTM E459-05 - Standard Test Method for Measuring Heat Transfer Rate Using a Thin-Skin Calorimeter
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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:E459–05
Standard Test Method for
Measuring Heat Transfer Rate Using a Thin-Skin
1
Calorimeter
This standard is issued under the fixed designation E459; 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.
1. Scope responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
1.1 This test method covers the design and use of a thin
bility of regulatory limitations prior to use.
metallic calorimeter for measuring heat transfer rate (also
calledheatflux).Thermocouplesareattachedtotheunexposed
2. Summary of Test Method
surface of the calorimeter.Aone-dimensional heat flow analy-
2.1 This test method for measuring the heat transfer rate to
sis is used for calculating the heat transfer rate from the
a metal calorimeter of finite thickness is based on the assump-
temperature measurements. Applications include aerodynamic
tion of one-dimensional heat flow, known metal properties
heating, laser and radiation power measurements, and fire
(density and specific heat), known metal thickness, and mea-
safety testing.
surement of the rate of temperature rise of the back (or
1.2 Advantages:
unexposed) surface of the calorimeter.
1.2.1 Simplicity of Construction—The calorimeter may be
2.2 After an initial transient, the response of the calorimeter
constructedfromanumberofmaterials.Thesizeandshapecan
is approximated by a lumped parameter analysis:
often be made to match the actual application. Thermocouples
may be attached to the metal by spot, electron beam, or laser dT
q5rC d (1)
p
dt
welding.
1.2.2 Heat transfer rate distributions may be obtained if
where:
metals with low thermal conductivity, such as some stainless
2
q = heat transfer rate, W/m ,
steels, are used.
3
r = metal density, kg/m ,
1.2.3 The calorimeters can be fabricated with smooth sur-
d = metal thickness, m,
faces,withoutinsulatorsorplugsandtheattendanttemperature
C = metal specific heat, J/kg·K, and
p
discontinuities, to provide more realistic flow conditions for
dT/dt = back surface temperature rise rate, K/s.
aerodynamic heating measurements.
1.2.4 The calorimeters described in this test method are 3. Significance and Use
relatively inexpensive. If necessary, they may be operated to
3.1 This test method may be used to measure the heat
burn-out to obtain heat transfer information.
transfer rate to a metallic or coated metallic surface for a
1.3 Limitations:
variety of applications, including:
1.3.1 At higher heat flux levels, short test times are neces-
3.1.1 Measurements of aerodynamic heating when the calo-
sary to ensure calorimeter survival.
rimeter is placed into a flow environment, such as a wind
1.3.2 For applications in wind tunnels or arc-jet facilities,
tunnel or an arc jet; the calorimeters can be designed to have
the calorimeter must be operated at pressures and temperatures
the same size and shape as the actual test specimens to
such that the thin-skin does not distort under pressure loads.
minimize heat transfer corrections;
Distortion of the surface will introduce measurement errors.
3.1.2 Heat transfer measurements in fires and fire safety
1.4 The values stated in SI units are to be regarded as the
testing;
standard. The values given in parentheses are for information
3.1.3 Laser power and laser absorption measurements; as
only.
well as,
1.5 This standard does not purport to address all of the
3.1.4 X-ray and particle beam (electrons or ions) dosimetry
safety concerns, if any, associated with its use. It is the
measurements.
3.2 The thin-skin calorimeter is one of many concepts used
1
to measure heat transfer rates. It may be used to measure
This test method is under the jurisdiction of ASTM Committee E21 on Space
Simulation andApplications of SpaceTechnology and is the direct responsibility of
convective, radiative, or combinations of convective and ra-
Subcommittee E21.08 on Thermal Protection.
diative (usually called mixed or total) heat transfer rates.
Current edition approved Sept. 15, 2005. Published September 2005. Originally
However, when the calorimeter is used to measure radiative or
approved in 1972. Last previous edition approved in 1997 as E459–97. DOI:
mixedheattransferrates,theabsorptivityandreflectivityofthe
10.1520/E0459-05.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
1

---------------------- Page: 1 ----------------------
E459–05
FIG. 1 Typical Thin-Skin Calorimeter for Heat Transfer Measurement
2
surface should be measured over the expected radiation wave- couple that is soldered to
...

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5.2 Sources of error involving the null-point calorimeter in high heat-flux measurement applications are extensively discussed in Refs (3-7). In particular, it has been shown both analytically and experimentally that the thickness of the copper above the null-point cavity is critical. If the thickness is too great, the time response of the instrument will not be fast enough to pick up important flow characteristics. On the other hand, if the thickness is too small, the null-point calorimeter will indicate significantly larger (and time dependent) values than the input or incident heat flux. Therefore, all null-point calorimeters should be experimentally checked for proper time response and calibration before they are used. Although a calibration apparatus is not very difficult or expensive to fabricate, there is only one known system presently in existence (6 and 7). The design of null-point calorimeters can be accomplished from the data in this documentation. However, fabrication of these sensors is a difficult task. Since there is not presently a significant market for null-point calorimeters, commercial sources of these sensors are few. Fabrication details are generally regarded as proprietary information. Some users have developed me...
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1.1 This test method covers the measurement of the heat-transfer rate or the heat flux to the surface of a solid body (test sample) using the measured transient temperature rise of a thermocouple located at the null point of a calorimeter that is installed in the body and is configured to simulate a semi-infinite solid. By definition the null point is a unique position on the axial centerline of a disturbed body which experiences the same transient temperature history as that on the surface of a solid body in the absence of the physical disturbance (hole) for the same heat-flux input.  
1.2 Null-point calorimeters have been used to measure high convective or radiant heat-transfer rates to bodies immersed in both flowing and static environments of air, nitrogen, carbon dioxide, helium, hydrogen, and mixtures of these and other gases. Flow velocities have ranged from zero (static) through subsonic to hypersonic, total flow enthalpies from 1.16 to greater than 4.65 × 101 MJ/kg (5 × 10 2 to greater than 2 × 104 Btu/lb.), and body pressures from 105 to greater than 1.5 × 107 Pa (atmospheric to greater than 1.5 × 102 atm). Measured heat-transfer rates have ranged from 5.68 to 2.84 × 102 MW/m2 (5 × 102 to 2.5 × 104 Btu/ft2-sec).  
1.3 The most common use of null-point calorimeters is to measure heat-transfer rates at the stagnation point of a solid body that is immersed in a high pressure, high enthalpy flowing gas stream, with the body axis usually oriented parallel to the flow axis (zero angle-of-attack). Use of null-point calorimeters at off-stagnation point locations and for angle-of-attack testing may pose special problems of calorimeter design and data interpretation.  
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 appli...

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ASTM E511-07(2020)(Test Method)
Standard Test Method for Measuring Heat Flux Using a Copper-Constantan Circular Foil, Heat-Flux Transducer

SIGNIFICANCE AND USE
3.1 Fig. 1 is a sectional view of an example circular foil heat-flux transducer. It consists of a circular Constantan foil attached by a metallic bonding process to a heat sink of oxygen-free high conductivity copper (OFHC), with copper leads attached at the center of the circular foil and at any point on the heat-sink body. The transducer impedance is usually less than 1 V. To minimize current flow, the data acquisition system (DAS) should be a potentiometric system or have an input impedance of at least 100 000 Ω.  
3.2 As noted in 2.3, an approximately linear output (versus heat flux) is produced when the body and center wire of the transducer are constructed of copper and the circular foil is constantan. Other metal combinations may be employed for use at higher temperatures, but most (4) are nonlinear.  
3.3 Because the thermocouple junction at the edge of the foil is the reference for the center thermocouple, no cold junction compensation is required with this instrument. The wire leads used to convey the signal from the transducer to the readout device are normally made of stranded, tinned copper, insulated with TFE-fluorocarbon and shielded with a braid over-wrap that is also TFE-fluorocarbon-covered.  
3.4 Transducers with a heat-sink thermocouple can be used to indicate the foil center temperature. Once the edge temperature is known, the temperature difference from the foil edge to its center may be directly read from the copper-constantan (Type T) thermocouple table. This temperature difference then is added to the body temperature, indicating the foil center temperature.  
3.5 Water-Cooled Transducer:  
3.5.1 A water-cooled transducer should be used in any application where the copper heat-sink would rise above 235 °C (450 °F) without cooling. Examples of cooled transducers are shown in Fig. 2. The coolant flow must be sufficient to prevent local boiling of the coolant inside the transducer body, with its characteristic pulsations (“chugging”) of t...
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1.1 This test method describes the measurement of radiative heat flux using a transducer whose sensing element (1, 2)2 is a thin circular metal foil. These sensors are often called Gardon Gauges.  
1.2 The values stated in SI units are to be regarded as the standard. The values stated in parentheses are provided for information only.  
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
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 E3057-19(Test Method)
Standard Test Method for Measuring Heat Flux Using Directional Flame Thermometers with Advanced Data Analysis Techniques

SIGNIFICANCE AND USE
5.1 Need for Heat Flux Measurements:  
5.1.1 Independent measurements of temperature and heat flux support the development and validation of engineering models of fires and other high environments, such as furnaces. For tests of fire protection materials and structural assemblies, temperature and heat flux are necessary to fully specify the boundary conditions, also known as the thermal exposure. Temperature measurements alone cannot provide a complete set of boundary conditions.  
5.1.2 Temperature is a scalar variable and a primary variable. Heat Flux is a vector quantity, and it is a derived variable. As a result, they should be measured separately just as current and voltage are in electrical systems. For steady-state or quasi-steady state conditions, analysis basically uses a thermal analog of Ohm's Law. The thermal circuit uses the temperature difference instead of voltage drop, the heat flux in place of the current and thermal resistance in place of electrical resistance. As with electrical systems, the thermal performance is not fully specified without knowing at least two of these three parameters (temperature drop, heat flux, or thermal resistance). For dynamic thermal experiments like fires or fire safety tests, the electrical capacitance is replaced by the volumetric heat capacity.  
5.1.3 The net heat flux, which is measured by a DFT, is likely different than the heat flux into the test item of interest because of different surface temperatures. An alternative measurement is the total cold wall heat flux which is measured by water-cooled Gardon or S-B gauges. The incident radiative flux can be estimated from either measurement by use of an energy balance [Keltner, 2007 and 2008 (16, 17)]. The convective flux can be estimated from gas temperatures and the convective heat transfer coefficient, h [Janssens, 2007 (18)]. Assuming the sensor is physically close to the test item of interest; one can use the incident radiative and convective fluxes from the...
SCOPE
1.1 This test method describes the continuous measurement of the hemispherical heat flux to one or both surfaces of an uncooled sensor called a “Directional Flame Thermometer” (DFT).  
1.2 DFTs consist of two heavily oxidized, Inconel 600 plates with mineral insulated, metal-sheathed (MIMS) thermocouples (TCs, type K) attached to the unexposed faces and a layer of ceramic fiber insulation placed between the plates.  
1.3 Post-test calculations of the net heat flux can be made using several methods. The most accurate method uses an inverse heat conduction code. Nonlinear inverse heat conduction analysis uses a thermal model of the DFT with temperature dependent thermal properties along with the two plate temperature measurement histories. The code provides transient heat flux on both exposed faces, temperature histories within the DFT as well as statistical information on the quality of the analysis.  
1.4 A second method uses a transient energy balance on the DFT sensing surface and insulation, which uses the same temperature measurements as in the inverse calculations to estimate the net heat flux.  
1.5 A third method uses Inverse Filter Functions (IFFs) to provide a near real time estimate of the net flux. The heat flux history for the “front face” (either surface exposed to the heat source) of a DFT can be calculated in real-time using a convolution type of digital filter algorithm.  
1.6 Although developed for use in fires and fire safety testing, this measurement method is quite broad in potential fields of application because of the size of the DFTs and their construction. It has been used to measure heat flux levels above 300 kW/m2 in high temperature environments, up to about 1250 °C, which is the generally accepted upper limit of Type K or N thermocouples.  
1.7 The transient response of the DFTs is limited by the response of the MIMS TCs. The larger the thermocouple the slower the transient response. Res...

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ASTM E2684-17(Test Method)
Standard Test Method for Measuring Heat Flux Using Surface-Mounted One-Dimensional Flat Gages

SIGNIFICANCE AND USE
5.1 This test method will provide guidance for the measurement of the net heat flux to or from a surface location. To determine the radiant energy component the emissivity or absorptivity of the gage surface coating is required and should be matched with the surrounding surface. The potential physical and thermal disruptions of the surface due to the presence of the gage should be minimized and characterized. For the case of convection and low source temperature radiation to or from the surface it is important to consider how the presence of the gage alters the surface heat flux. The desired quantity is usually the heat flux at the surface location without the presence of the gage.  
5.1.1 Temperature limitations are determined by the gage material properties and the method of application to the surface. The range of heat flux that can be measured and the time response are limited by the gage design and construction details. Measurements from 10 W/m2 to above 100 kW/m2 are easily obtained with current sensors. Time constants as low as 10 ms are possible, while thicker sensors may have response times greater than 1 s. It is important to choose the sensor style and characteristics to match the range and time response of the required application.  
5.2 The measured heat flux is based on one-dimensional analysis with a uniform heat flux over the surface of the gage surface. Because of the thermal disruption caused by the placement of the gage on the surface, this may not be true. Wesley (3) and Baba et al. (4) have analyzed the effect of the gage on the thermal field and heat transfer within the surface substrate and determined that the one-dimensional assumption is valid when:
   where:
  ks  =   the thermal conductivity of the substrate material,    R   =  the effective radius of the gage,    δ  =  the combined thickness, and     k  =  the effective thermal conductivity of the gage and adhesive layers.    
5.3 Measurements of convective heat flux are part...
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1.1 This test method describes the measurement of the net heat flux normal to a surface using flat gages mounted onto the surface. Conduction heat flux is not the focus of this standard. Conduction applications related to insulation materials are covered by Test Method C518 and Practices C1041 and C1046. The sensors covered by this test method all use a measurement of the temperature difference between two parallel planes normal to the surface to determine the heat that is exchanged to or from the surface in keeping with Fourier’s Law. The gages operate by the same principles for heat transfer in either direction.  
1.2 This test method is quite broad in its field of application, size and construction. Different sensor types are described in detail in later sections as examples of the general method for measuring heat flux from the temperature gradient normal to a surface (1).2 Applications include both radiation and convection heat transfer. The gages have broad application from aerospace to biomedical engineering with measurements ranging form 0.01 to 50 kW/m 2. The gages are usually square or rectangular and vary in size from 1 mm to 10 cm or more on a side. The thicknesses range from 0.05 to 3 mm.  
1.3 The values stated in SI units are to be regarded as the standard. The values stated in parentheses are provided for information only.  
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 and health practices and determine the applicability of regulatory limitations prior to use.  
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...

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