Standard Active Last Updated: May 17, 2021
ASTM E2820-13(2019)

Standard Test Method for Evaluating Thermal EMF Properties of Base-Metal Thermocouple Connectors

Significance and Use

5.1 A thermocouple connector, exposed to a temperature difference, contributes to the output of a thermocouple circuit. The output uncertainty allocated to the connector depends on the connector design and temperature gradient.

5.2 Connector performance can be classified based on the results of this method and used as part of a component specification.

5.3 The method can be used as an engineering tool for evaluating different connector designs tested under similar thermal conditions.


1.1 This standard describes a thermal emf test method for base-metal thermocouple connectors including Types E, J, K, N, and T. Standard connectors such as found in Specifications E1129/E1129M and E1684/E1684M as well as non-standard connector configurations and connector components can be evaluated using this method.

1.2 The measured emf is reported as an equivalent temperature deviation or error relative to a reference thermocouple of the same type. This method can be used to verify deviations introduced by the connector greater than or equal to 1°C.

1.3 The connector is tested with thermocouple contacts axially aligned with a temperature gradient using a specified thermal boundary condition. The actual temperature difference developed across the connector and corresponding error will depend on the connector design.

1.4 Connector contacts are often fabricated from raw materials having temperature-emf relationships in accordance with Specification E230/E230M. However, verifying Specification E230/E230M tolerances is not within the scope of this method.

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

1.6 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.

1.7 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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Book of Standards Volume: 14.03
Developed by Subcommittee: E20.13
Pages: 6
DOI: 10.1520/E2820-13R19
ICS Code: 17.200.20