ASTM E220-19 - 1.9.2019
 
Significance and Use

5.1 For users or manufacturers of thermocouples, this test method provides a means of verifying the emf-temperature characteristics of the material prior to use.

5.2 This test method can be used to calibrate a thermocouple for use as a reference, or it can be used to calibrate thermocouples representing a batch of purchased, assembled thermocouples.

5.3 This test method can be used for the verification of the conformance of thermocouple materials to temperature tolerances for specifications such as the tables in Specification E230 or other special specifications as required for commercial, military, or research applications.

 
1. Scope

1.1 This test method describes the principles, apparatus, and procedure for calibrating thermocouples by comparison with a reference thermometer. Calibrations are covered over temperature ranges appropriate to the individual types of thermocouples within an overall range from approximately −195 °C to 1700 °C (−320 °F to 3100 °F).

1.2 In general, this test method is applicable to unused thermocouples. This test method does not apply to used thermocouples due to their potential material inhomogeneity—the effects of which cannot be identified or quantified by standard calibration techniques. Thermocouples with large-diameter thermoelements and sheathed thermocouples may require special care to control thermal conduction losses.

1.3 In this test method, all values of temperature are based on the International Temperature Scale of 1990. See Guide E1594.

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 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 Trade (TBT) Committee.

 
2. Referenced Documents

E77-14(2021)

Standard Test Method for Inspection and Verification of Thermometers

E1751-00

Standard Guide for Temperature Electromotive Force (emf) Tables for Non-Letter Designated Thermocouple Combinations (Withdrawn 2009)

E1-14(2020)

Standard Specification for ASTM Liquid-in-Glass Thermometers

E2846-20

Standard Guide for Thermocouple Verification

E1684-10

Standard Specification for Miniature Thermocouple Connectors

E1594-22

Standard Guide for Expression of Temperature

E1129/E1129M-19

Standard Specification for Thermocouple Connectors

E644-11(2019)

Standard Test Methods for Testing Industrial Resistance Thermometers

E230-03

Standard Specification and Temperature-Electromotive Force (EMF) Tables for Standardized Thermocouples

E344-23

Terminology Relating to Thermometry and Hydrometry

E452-02(2023)

Standard Test Method for Calibration of Refractory Metal Thermocouples Using a Radiation Thermometer

E563-22

Standard Practice for Preparation and Use of an Ice-Point Bath as a Reference Temperature