ASTM C1041-10

Standard Practice for In-Situ Measurements of Heat Flux in Industrial Thermal Insulation Using Heat Flux Transducers (Withdrawn 2019)

SIGNIFICANCE AND USE
The major contribution of this practice is that it enables a measurement of the real-time energy loss or gain through a chosen surface of an existing process insulation with minimal disturbance to the heat flux through the insulating body.
The primary use of this practice will be for the in-situ estimation of thermal transport properties of industrial insulation such as used on pipes, tanks, ovens, and boilers, operating under normal process conditions.
Errors attributable to heat flow measurements over a small area or short term testing can be misleading and this practice is intended to minimize such errors.
Insulation processes with large temperature differences across the insulation are best suited to HFT measurements because modest changes in ambient conditions have but minimal effects on HFT output.
While it would be ideal for the HFT and attachment system to have zero thermal resistance, this factor is insignificant to the measured result if kept to 5 % or less of the resistance of the insulating section being tested.
SCOPE
1.1 This practice covers the in-situ measurement of heat flux through industrial thermal insulation using a heat flux transducer (HFT).
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.  
1.3 This practice estimates the thermal transport properties of thermal insulation materials in-situ in field applications under pseudo steady-state conditions. It is not intended that this practice should be used as a substitute for more precise laboratory procedures such as Test Methods C177, C335, or C518.
1.4 This practice is limited by the relatively small area that can be covered by an HFT and by the transient effects of environmental conditions.
1.5 Temperature limitations shall be as specified by the manufacturer of the HFT.
1.6 While accurate values of heat flux are highly dependent upon proper calibrations under the conditions of use, it is acceptable to use the calibrations provided by the manufacturer of the HFT for comparative work between similar materials, aging, or other conditions of use.
Note 1—Further information may be found in the literature (1-6).  
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 and health practices and determine the applicability of regulatory limitations prior to use.
WITHDRAWN RATIONALE
This practice covers the in-situ measurement of heat flux through industrial thermal insulation using a heat flux transducer (HFT).
Formerly under the jurisdiction of Committee C16 on Thermal Insulation, this practice was withdrawn in January 2019 in accordance with section 10.6.3 of the Regulations Governing ASTM Technical Committees, which requires that standards shall be updated by the end of the eighth year since the last approval date.

General Information

• Status: Withdrawn
• Publication Date: 31-May-2010
• Withdrawal Date: 14-Jan-2019
• ICS: 27.220 - Heat recovery. Thermal insulation
• Technical Committee: C16 - Thermal Insulation
• Drafting Committee: C16.30 - Thermal Measurement

Relations

• Referred By: ASTM C1130-21 - Standard Practice for Calibration of Thin Heat Flux Transducers
• Effective Date: 01-Jun-2010
• Referred By: ASTM E2684-17 - Standard Test Method for Measuring Heat Flux Using Surface-Mounted One-Dimensional Flat Gages
• Effective Date: 01-Jun-2010

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: C1041 − 10
Standard Practice for
In-Situ Measurements of Heat Flux in Industrial Thermal
1
Insulation Using Heat Flux Transducers
This standard is issued under the fixed designation C1041; 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 2. Referenced Documents
3
2.1 ASTM Standards:
1.1 Thispracticecoversthein-situmeasurementofheatflux
C177 Test Method for Steady-State Heat Flux Measure-
through industrial thermal insulation using a heat flux trans-
ments and Thermal Transmission Properties by Means of
ducer (HFT).
the Guarded-Hot-Plate Apparatus
1.2 The values stated in SI units are to be regarded as the
C335 Test Method for Steady-State Heat Transfer Properties
standard. The values given in parentheses are for information
of Pipe Insulation
only. C518 Test Method for Steady-State Thermal Transmission
Properties by Means of the Heat Flow Meter Apparatus
1.3 This practice estimates the thermal transport properties
E220 Test Method for Calibration of Thermocouples By
of thermal insulation materials in-situ in field applications
Comparison Techniques
underpseudosteady-stateconditions.Itisnotintendedthatthis
E230 Specification and Temperature-Electromotive Force
practice should be used as a substitute for more precise
(EMF) Tables for Standardized Thermocouples
laboratory procedures such as Test Methods C177, C335,or
C518.
3. Terminology
1.4 This practice is limited by the relatively small area that 3.1 Definitions:
can be covered by an HFT and by the transient effects of 3.1.1 heat flux transducer (HFT)—a rigid or flexible trans-
environmental conditions. ducer in a durable housing comprised of a thermopile or
equivalent for sensing the temperature drop across a thin
1.5 Temperature limitations shall be as specified by the
thermal resistance layer which gives a voltage output propor-
manufacturer of the HFT.
tional to the heat flux through the transducer.
3.1.1.1 belt HFT—a heat flux transducer having a belt-like
1.6 While accurate values of heat flux are highly dependent
configuration such that the unit can be wrapped helically
upon proper calibrations under the conditions of use, it is
around a section of pipe insulation (see Fig. 1).
acceptable to use the calibrations provided by the manufacturer
3.1.1.2 spot HFT—a small heat flux transducer having a
of the HFT for comparative work between similar materials,
round, square, rectangular or other configuration for the
aging, or other conditions of use.
sensitive area (see Fig. 1).
2
NOTE 1—Further information may be found in the literature (1-6).
3.1.2 pseudo steady state of HFT—the criterion for pseudo
steady-stateconditionisthattheaverageHFTreadingovertwo
1.7 This standard does not purport to address all of the
consecutive 5-min periods does not differ by more than 2 %.
safety concerns, if any, associated with its use. It is the
Since the time constant of an HFT is typically less than or of
responsibility of the user of this standard to establish appro-
the order of 1 min, using a time interval of 5 min ensures that
priate safety and health practices and determine the applica-
the transient effects in the HFT are averaged.
bility of regulatory limitations prior to use.
3.2 Symbols:
3.2.1 Q—heat flow, W (Btu/h).
2 2
1
3.2.2 q—heat flux, W/m (Btu/h·ft ).
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 June 1, 2010. Published September 2010. Originally
3
approved in 1985. Last previous edition approved in 2007 as C1041 – 85 (2007). For referenced ASTM standards, visit the ASTM website, www.astm.org, or
DOI: 10.1520/C1041-10. contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
2
The boldface numbers in parentheses refer to the list of references at the end of Standards volume information, refer to the standard’s Document Summary page on
this standard. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
C1041 − 10
tion such as used on pipes, tanks, ovens, and boilers, operating
under normal process conditions.
5.3 Errors attributable to heat flow measurements over a
small area or short term testing can be misleading and this
practice is intended to minimize such errors.
5.4 Insulation processes with large temperature differences
across the insulation are best suited to HFT measurements
because modest changes in ambient conditions have but
minimal ef
...