• Skip to main content
  • Skip to header right navigation
  • Skip to site footer

1-800-685-2088 | support@mat-cs.com

  • LinkedIn
MAT-CS - Materials Characterization Services

Materials Characterization Services

  • Home
  • About
    • Meet the Team
    • Consulting
  • Analytical Techniques
    • Bulk Analysis
    • Microscopy and Microanalytical
    • Surface and Thin Film
    • Polymer Characterization
    • Optical Measurements
    • Liquids and Gases
    • Electrical / Electronics
    • Reliability Testing
    • Miscellaneous
  • Test Methods
    • ASTM Methods List
    • ISO Methods List
    • AATCC
    • AOAC
    • AOCS
    • EPA, SM
    • FDA BAM
    • IP
    • JEDEC
    • MIL-STD
    • OCSPP
    • OPPTS
    • REACH
    • RoHS
    • SEMI
    • TAPPI
    • USP/EP/JP
  • Resources
    • Experiment Design
    • Consulting
    • The Laboratory Landscape
    • Quality Programs
    • Regulatory-Based Analyses
  • Contact
  • Get a Quote!
MAT-CS Home Cover

ASTM C1371

ASTM C1371 – Standard Test Method for Determination of Emittance of Materials Near Room Temperature Using Portable Emissometers

Description:

Significance and Use

5.1 Surface Emittance Testing: 

5.1.1 Heat transfer from a surface by radiation transfer is reduced if the surface of a material has a low emittance. Since the controlling factor in the use of insulation is sometimes condensation control or personnel protection, it is important to understand that a low emittance will change the surface temperature of a material. One possible criterion in the selection of these materials is the question of the effect of aging on the surface emittance. If the initial low surface emittance of a material is not maintained during service, then the long-term value of the material is diminished.

5.1.2 This test method provides a means for comparative periodic testing of low emittance surfaces in the field. In this way the effects of aging on the reflective properties can be monitored.

5.1.3 This test method determines the total hemispherical emittance with a precision of better than ±0.02 units.(1) The emittances of the calibration standards shall have been obtained from accurate independent measurements of total hemispherical emittance. This test method shall not be used for specimens that are highly anisotropic or transparent to infrared radiation. This test method also shall not be used for specimens with significant thermal resistance (see 7.3.4).

5.1.4 Once a reliable emittance measurement has been determined, the value is available to be used to calculate radiative heat flow from the subject surface. For example, if the temperature of the surface, T1, and the temperature of the surroundings, T2, are known, then the radiative heat flow, Qrad, is given by:

Equation C1371-15R22_1

where A is the area of the surface, and either A is assumed to be much smaller than the area of the surroundings or the emittance of the surroundings is assumed to be unity. This radiative heat flow when combined with convective and conductive heat flows provides the total heat flow from the surface (a method for calculating total heat flow is described in Practice C680).

Scope

1.1 This test method covers a technique for determination of the emittance of opaque and highly thermally conductive materials using a portable differential thermopile emissometer. The purpose of the test method is to provide a comparative means of quantifying the emittance of materials near room temperature.

1.2 This test method does not supplant Test Method C835, which is an absolute method for determination of total hemispherical emittance, or Test Method E408, which includes two comparative methods for determination of total normal emittance. Because of the unique construction of the portable emissometer, it can be calibrated to measure the total hemispherical emittance. This is supported by comparison of emissometer measurements with those of Test Method C835 (1).2

1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

Related Test Methods

ASTM D483

ASTM D4829

ASTM D4828

ASTM D4824

ASTM D482

ASTM D4815

ASTM D4814

ASTM D4812

ASTM D4811

ASTM D4810

ASTM D4809

ASTM D4808

Previous Post:MAT-CS Home CoverASTM C1350
Next Post:ASTM C1421MAT-CS Home Cover

Ready to start your analysis?

Get a Quote!
MAT-CS

Your One Source for Materials Analysis

1-800-685-2088

support@mat-cs.com

  • Home
  • Analytical Techniques
  • Test Methods
  • Resources
  • Contact Us
  • Get a Quote!
  • Special Analysis Request

  • LinkedIn

Copyright © 2025 by Materials Characterization Services · All Rights Reserved
Website Built, Hosted, and Managed by Digital Donkey Marketing