ASTM C1043-16
Standard Practice for Guarded-Hot-Plate Design Using Circular Line-Heat Sources

Standard No.

ASTM C1043-16

Release Date

2016

Published By

American Society for Testing and Materials (ASTM)

Status

Be replaced

Replace By

ASTM C1043-19

Latest

ASTM C1043-24

Scope

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 circular line-heat sources in a guarded hot plate simplifies construction and repair. For room-temperature operation, the plates are typically of one-piece metal construction and thus are easily fabricated to the required thickness and flatness. The design of the gap is also simplified, relative to gap designs for distributed-heat-source hot plates.

4.7 In the single-sided mode of operation (see Practice C1044), the symmetry of the line-heat-source design in the axial direction minimizes errors due to undesired heat flow across the gap.

1.1......

ASTM C1043-16 Referenced Document

• ASTM C1044 Standard Practice for Using a Guarded-Hot-Plate Apparatus or Thin-Heater Apparatus in the Single-Sided Mode
• ASTM C168 Standard Terminology Relating to Thermal Insulation
• ASTM C177 Standard Test Method for Steady-State Heat Flux Measurements and Thermal Transmission Properties by Means of the Guarded-Hot-Plate Apparatus
• ASTM E230 Standard Specification and Temperature-Electromotive Force (EMF) Tables for Standardized Thermocouples

ASTM C1043-16 history

• 2024 ASTM C1043-24 Standard Practice for Guarded-Hot-Plate Design Using Circular Line-Heat Sources
• 2019 ASTM C1043-19 Standard Practice for Guarded-Hot-Plate Design Using Circular Line-Heat Sources
• 2016 ASTM C1043-16 Standard Practice for Guarded-Hot-Plate Design Using Circular Line-Heat Sources
• 2006 ASTM C1043-06(2010) Standard Practice for Guarded-Hot-Plate Design Using Circular Line-Heat Sources
• 2006 ASTM C1043-06 Standard Practice for Guarded-Hot-Plate Design Using Circular Line-Heat Sources
• 1997 ASTM C1043-97(2002) Standard Practice for Guarded-Hot-Plate Design Using Circular Line-Heat Sources
• 1997 ASTM C1043-97 Standard Practice for Guarded-Hot-Plate Design Using Circular Line-Heat Sources