ASTM E601-20

Standard Guide for Measuring Electromotive Force (EMF) Stability of Base-Metal Thermoelement Materials With Time in Air

SIGNIFICANCE AND USE
5.1 This test is important because the accuracy of a temperature measurement by a thermocouple is directly related to the emf stability of the thermoelements.  
5.2 This test is used to verify that the tested thermoelements meet the intended requirements.  
5.3 This test is useful in comparing the emf stability of two base metal thermoelements under the same conditions. The test and reference emf may be measured either simultaneously or alternately.  
5.4 The relative stabilities of base metal thermoelements determined by this test are valid only under the specified test conditions. Results will be affected by changes in any of the following conditions: (1) temperature profile or gradient along the length of the thermoelements, (2) abundance, velocity and composition of the air surrounding the test pieces, (3) thermoelectric inhomogeneity of the test thermoelements, and (4) stability of the platinum thermoelement.  
5.5 The test does not address the determination of base metal thermoelement stabilities over a series of temperature changes.  
5.6 The reliability of this test depends on the emf stability of the reference platinum thermoelement. For testing the relative emf stability of base-metal thermoelements, a reference element of platinum that has sufficient thermoelectric stability to determine any significant change in emf of base-metal thermoelements shall be used. To ascertain that the experimental method protects the platinum sufficiently from degradation, the method shall be validated by performing the procedure described in Appendix X1 prior to the actual test.  
5.7 The test result does not apply to applications in which the temperature distribution, for a given measuring junction temperature, changes with time.
SCOPE
1.1 This guide provides a method for measuring the emf stability of base-metal thermoelement materials in air referenced to platinum at specified constant elevated temperatures using dual, simultaneous, emf indicators, or using a single emf indicator, with the test and reference emf measured alternately. This test is conducted over a period of weeks.  
1.2 A calibrated platinum-rhodium/platinum thermocouple is used as a reference standard to establish the test temperature.  
1.3 The useful life of a thermocouple depends on the stability of the emf generated at given temperatures for a required time interval. This method provides a quantitative measure of the stability of individual thermoelements. By combining the results of the positive (P) and negative (N) thermoelements, the stability of a thermocouple comprised of both P and N thermoelements may be obtained. The emf of an individual thermoelement is measured against platinum, which may be the platinum leg of the platinum-rhodium/platinum reference thermocouple, or an additional platinum reference.
Note 1: Some thermoelements may show insignificant emf drift while undergoing relatively rapid oxidation. In these cases, failure of the thermoelement may be indicated only by a large rise in the electrical resistance between joined thermoelements, as measured at the reference junctions.
Note 2: See ASTM MNL12 for recommended upper temperature limits in air.2
Note 3: This guide is only applicable for initially new unused thermoelements. Base-metal thermoelements exposed to temperatures above 200 °C become thermoelectrically inhomogeneous, and stability testing of inhomogeneous thermoelements will give ambiguous results.  
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 ...

General Information

• Status: Published
• Publication Date: 31-Oct-2020
• ICS: 17.200.20 - Temperature-measuring instruments
• Technical Committee: E20 - Temperature Measurement
• Drafting Committee: E20.11 - Thermocouples - Calibration

Standards Content (Sample)

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.
Designation: E601 − 20 An American National Standard
Standard Guide for
Measuring Electromotive Force (EMF) Stability of Base-
1
Metal Thermoelement Materials With Time in Air
This standard is issued under the fixed designation E601; 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 priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use.
1.1 This guide provides a method for measuring the emf
1.5 This international standard was developed in accor-
stability of base-metal thermoelement materials in air refer-
dance with internationally recognized principles on standard-
enced to platinum at specified constant elevated temperatures
ization established in the Decision on Principles for the
using dual, simultaneous, emf indicators, or using a single emf
Development of International Standards, Guides and Recom-
indicator, with the test and reference emf measured alternately.
mendations issued by the World Trade Organization Technical
This test is conducted over a period of weeks.
Barriers to Trade (TBT) Committee.
1.2 A calibrated platinum-rhodium/platinum thermocouple
2. Referenced Documents
is used as a reference standard to establish the test temperature.
3
2.1 ASTM Standards:
1.3 The useful life of a thermocouple depends on the
E220 Test Method for Calibration of Thermocouples By
stability of the emf generated at given temperatures for a
Comparison Techniques
required time interval. This method provides a quantitative
E230/E230M Specification for Temperature-Electromotive
measure of the stability of individual thermoelements. By
Force (emf) Tables for Standardized Thermocouples
combining the results of the positive (P) and negative (N)
E344 Terminology Relating to Thermometry and Hydrom-
thermoelements, the stability of a thermocouple comprised of
etry
both P and N thermoelements may be obtained. The emf of an
E563 Practice for Preparation and Use of an Ice-Point Bath
individual thermoelement is measured against platinum, which
as a Reference Temperature
may be the platinum leg of the platinum-rhodium/platinum
E1159 Specification for Thermocouple Materials, Platinum-
reference thermocouple, or an additional platinum reference.
Rhodium Alloys, and Platinum
NOTE 1—Some thermoelements may show insignificant emf drift while
4
undergoing relatively rapid oxidation. In these cases, failure of the 2.2 NIST Document:
thermoelement may be indicated only by a large rise in the electrical
Monograph 175
resistance between joined thermoelements, as measured at the reference
junctions.
3. Terminology
NOTE 2—See ASTM MNL12 for recommended upper temperature
2
3.1 Definitions:
limits in air.
3.1.1 ThedefinitionsgiveninTerminologyE344shallapply
NOTE 3—This guide is only applicable for initially new unused
thermoelements. Base-metal thermoelements exposed to temperatures
to this guide.
above 200 °C become thermoelectrically inhomogeneous, and stability
3.2 Definitions of Terms Specific to This Standard:
testing of inhomogeneous thermoelements will give ambiguous results.
3.2.1 emf indicator, n—an instrument that measures the emf
1.4 This standard does not purport to address all of the
and displays the value, for example, a digital voltmeter
safety concerns, if any, associated with its use. It is the
(DVM).
responsibility of the user of this standard to establish appro-
3.2.2 emf stability, n—change in emf (or in equivalent
temperature) with time, with the thermocouple junctions held
at fixed temperatures and with the thermal profile along the
1
This guide is under the jurisdiction of ASTM Committee E20 on Temperature
thermoelements held constant; this is also referred to in this
Measurement and is the direct responsibility of Subcommittee E20.11 on Thermo-
standard as drift.
couples - Calibration.
Current edition approved Nov. 1, 2020. Published December 2020. Originally
3
approved in 1977. Last previous edition approved in 2015 as E601 – 15. DOI: For referenced ASTM standards, visit the ASTM website, www.astm.org, or
10.1520/E0601-20. contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
2
Park RM, et al., Manual on the Use of Thermocouples in Temperature Standards volume information, refer to the standard’s Document Summary page on
Measurement: Fourth Edition, ASM MNL12, ASTM International, 1993. Available the ASTM website.
4
fromASTM Headquarters, 100 Barr Harbor Drive, West C
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: E601 − 15 E601 − 20
Standard Guide for
Measuring Electromotive Force (emf)(EMF) Stability of Base-
1
Metal Thermoelement Materials withWith Time in Air
This standard is issued under the fixed designation E601; 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
1.1 This guide provides a method for measuring the emf stability of base-metal thermoelement materials in air referenced to
platinum at specified constant elevated temperatures using dual, simultaneous, emf indicators, or using a single emf indicator, with
the test and reference emf measured alternately. This test is conducted over a period of weeks.
1.2 A calibrated platinum-rhodium/platinum thermocouple is used as a reference standard to establish the test temperature.
1.3 The useful life of a thermocouple depends on the stability of the emf generated at given temperatures for a required time
interval. This method provides a quantitative measure of the stability of individual thermoelements. By combining the results of
the positive (P) and negative (N) thermoelements, the stability of a thermocouple comprised of both P and N thermoelements may
be obtained. The emf of an individual thermoelement is measured against platinum, which may be the platinum leg of the
platinum-rhodium/platinum reference thermocouple, or an additional platinum reference.
NOTE 1—Some thermoelements may show insignificant emf drift while undergoing relatively rapid oxidation. In these cases, failure of the thermoelement
may be indicated only by a large rise in the electrical resistance between joined thermoelements, as measured at the reference junctions.
2
NOTE 2—See ASTM MNL 12MNL12 for recommended upper temperature limits in air.
NOTE 3—This guide is only applicable for initially new unused thermoelements. Base-metal thermoelements exposed to temperatures above 200°C 200
°C become thermoelectrically inhomogeneous, and stability testing of inhomogeneous thermoelements will give ambiguous results.
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 safety, health, and healthenvironmental 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
3
2.1 ASTM Standards:
1
This guide is under the jurisdiction of ASTM Committee E20 on Temperature Measurement and is the direct responsibility of Subcommittee E20.11 on Thermocouples
- Calibration.
Current edition approved May 1, 2015Nov. 1, 2020. Published June 2015December 2020. Originally approved in 1977. Last previous edition approved in 20132015 as
E601 – 07a (2013).E601 – 15. DOI: 10.1520/E0601-15.10.1520/E0601-20.
2
Park RM, et al., Manual on the Use of Thermocouples in Temperature Measurement: Fourth Edition, ASM MNL12, ASTM International, 1993. Available from ASTM
Headquarters, 100 Barr Harbor Drive, West Conshohocken, PA 19428, www.astm.org.
3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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E601 − 20
E220 Test Method for Calibration of Thermocouples By Comparison Techniques
E230E230/E230M Specification for Temperature-Electromotive Force (emf) Tables for Standardized Thermocouples
E344 Terminology Relating to Thermometry and Hydrometry
E563 Practice for Preparation and Use of an Ice-Point Bath as a Reference Temperature
E1159 Specification for Thermocouple Materials, Platinum-Rhodium Alloys, and Platinum
4
2.2 Other Referenced DocumentsNIST Document:
NIST Monograph 175
3. Terminology
3.1 Definitions—The definitions given in Terminology E344 shall apply to this gu
...