ASTM E230/E230M-23

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

ABSTRACT
This specification contains reference tables that give temperature-electromotive force (emf) relationships for types B, E, J, K, N, R, S, T, and C thermocouples. These are the thermocouple types most commonly used in industry. Thermocouples and matched thermocouple wire pairs are normally supplied to the tolerances on initial values of emf versus temperature. Color codes for insulation on thermocouple grade materials, along with corresponding thermocouple and thermoelement letter designations are given. Four types of tables are presented: general tables, EMF versus temperature tables for thermocouples, EMF versus temperature tables for thermoelements, and supplementary tables.
SCOPE
1.1 This specification contains reference tables (Tables 8 to 25) that give temperature-electromotive force (emf) relationships for Types B, C, E, J, K, N, R, S, and T thermocouples.2 These are the thermocouple types most commonly used in industry. The tables contain all of the temperature-emf data currently available for the thermocouple types covered by this standard and may include data outside of the recommended upper temperature limit of an included thermocouple type.  
1.2 In addition, the specification includes standard and special tolerances on initial values of emf versus temperature for thermocouples (Table 1), thermocouple extension wires (Table 2), and compensating extension wires for thermocouples (Table 3). Users should note that the stated tolerances apply only to the temperature ranges specified for the thermocouple types as given in Tables 1, 2, and 3, and do not apply to the temperature ranges covered in Tables 8 to 25.  
1.3 Tables 4 and 5 provide insulation color coding for thermocouple and thermocouple extension wires as customarily used in the United States.  
1.4 Recommendations regarding upper temperature limits for the thermocouple types referred to in 1.1 are provided in Table 6.  
1.5 Tables 26 to 45 give temperature-emf data for single-leg thermoelements referenced to platinum (NIST Pt-67). The tables include values for Types BP, BN, JP, JN, KP (same as EP), KN, NP, NN, TP, and TN (same as EN).  
1.6 Tables for Types RP, RN, SP, and SN thermoelements are not included since, nominally, Tables 18 to 21 represent the thermoelectric properties of Type RP and SP thermoelements referenced to pure platinum. Tables for the individual thermoelements of Type C are not included because materials for Type C thermocouples are normally supplied as matched pairs only.  
1.7 Polynomial coefficients which may be used for computation of thermocouple emf as a function of temperature are given in Table 7. Coefficients for the emf of each thermocouple pair as well as for the emf of most individual thermoelements versus platinum are included. Coefficients for type RP and SP thermoelements are not included since they are nominally the same as for types R and S thermocouples, and coefficients for type RN or SN relative to the nominally similar Pt-67 would be insignificant. Coefficients for the individual thermoelements of Type C thermocouples have not been established.  
1.8 Coefficients for sets of inverse polynomials are given in Table 46. These may be used for computing a close approximation of temperature (°C) as a function of thermocouple emf. Inverse functions are provided only for thermocouple pairs and are valid only over the emf ranges specified.  
1.9 This specification is intended to define the thermoelectric properties of materials that conform to the relationships presented in the tables of this standard and bear the letter designations contained herein. Topics such as ordering information, physical and mechanical properties, workmanship, testing, and marking are not addressed in this specification. The user is referred to specific standards such as Specifications E235, E574, E585/E585M, E608/E608M, E1159, or E2181/E2181M for guidance in these areas.  
1.10 The temperature-emf data in this specifica...

General Information

• Status: Historical
• Publication Date: 30-Apr-2023
• ICS: 17.200.20 - Temperature-measuring instruments
• Technical Committee: E20 - Temperature Measurement
• Drafting Committee: E20.11 - Thermocouples - Calibration

Relations

• Replaces: ASTM E230/E230M-17 - Standard Specification for Temperature-Electromotive Force (emf) Tables for Standardized Thermocouples
• Effective Date: 01-May-2023
• Replaced By: ASTM E230/E230M-23a - Standard Specification for Temperature-Electromotive Force (emf) Tables for Standardized Thermocouples
• Effective Date: 01-Nov-2023
• Referred By: ASTM D5931-20 - Standard Test Method for Density and Relative Density of Engine Coolant Concentrates and Aqueous Engine Coolants by Digital Density Meter
• Effective Date: 01-May-2023
• Referred By: ASTM D1881-17 - Standard Test Method for Foaming Tendencies of Engine Coolants in Glassware
• Effective Date: 01-May-2023
• Referred By: ASTM E1159-15(2020)e1 - Standard Specification for Thermocouple Materials, Platinum-Rhodium Alloys, and Platinum
• Effective Date: 01-May-2023
• Referred By: ASTM D3791/D3791M-11(2018) - Standard Practice for Evaluating the Effects of Heat on Asphalts
• Effective Date: 01-May-2023
• Referred By: ASTM E228-22 - Standard Test Method for Linear Thermal Expansion of Solid Materials With a Push-Rod Dilatometer
• Effective Date: 01-May-2023
• Referred By: ASTM D5869/D5869M-07a(2023) - Standard Practice for Dark Oven Heat Exposure of Roofing and Waterproofing Materials
• Effective Date: 01-May-2023
• Referred By: ASTM E235/E235M-23 - Standard Specification for Type K and Type N Mineral-Insulated, Metal-Sheathed Thermocouples for Nuclear or for Other High-Reliability Applications
• Effective Date: 01-May-2023
• Referred By: ASTM C372-94(2020) - Standard Test Method for Linear Thermal Expansion of Porcelain Enamel and Glaze Frits and Fired Ceramic Whiteware Products by Dilatometer Method
• Effective Date: 01-May-2023
• Referred By: ASTM D7935-20 - Standard Test Method for Corrosion Test for Non-Aqueous Engine Coolants in Glassware
• Effective Date: 01-May-2023
• Referred By: ASTM E2181/E2181M-19 - Standard Specification for Compacted Mineral-Insulated, Metal-Sheathed, Noble Metal Thermocouples and Thermocouple Cable
• Effective Date: 01-May-2023
• Referred By: ASTM B998-17 - Standard Guide for Hot Isostatic Pressing (HIP) of Aluminum Alloy Castings
• Effective Date: 01-May-2023
• Referred By: ASTM D3161/D3161M-20 - Standard Test Method for Wind Resistance of Steep Slope Roofing Products (Fan-Induced Method)
• Effective Date: 01-May-2023
• Referred By: ASTM E3119-19 - Standard Test Method for Accelerated Aging of Environmentally Controlled Dynamic Glazing
• Effective Date: 01-May-2023

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: E230/E230M − 23 An American National Standard
Standard Specification for
Temperature-Electromotive Force (emf) Tables for
1
Standardized Thermocouples
This standard is issued under the fixed designation E230/E230M; 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 elements of Type C are not included because materials for Type
C thermocouples are normally supplied as matched pairs only.
1.1 This specification contains reference tables (Tables 8 to
1.7 Polynomial coefficients which may be used for compu-
25) that give temperature-electromotive force (emf) relation-
2
tation of thermocouple emf as a function of temperature are
ships for Types B, C, E, J, K, N, R, S, and T thermocouples.
given in Table 7. Coefficients for the emf of each thermocouple
These are the thermocouple types most commonly used in
pair as well as for the emf of most individual thermoelements
industry. The tables contain all of the temperature-emf data
versus platinum are included. Coefficients for type RP and SP
currently available for the thermocouple types covered by this
thermoelements are not included since they are nominally the
standard and may include data outside of the recommended
same as for types R and S thermocouples, and coefficients for
upper temperature limit of an included thermocouple type.
type RN or SN relative to the nominally similar Pt-67 would be
1.2 In addition, the specification includes standard and
insignificant. Coefficients for the individual thermoelements of
special tolerances on initial values of emf versus temperature
Type C thermocouples have not been established.
for thermocouples (Table 1), thermocouple extension wires
1.8 Coefficients for sets of inverse polynomials are given in
(Table 2), and compensating extension wires for thermo-
Table 46. These may be used for computing a close approxi-
couples (Table 3). Users should note that the stated tolerances
mation of temperature (°C) as a function of thermocouple emf.
apply only to the temperature ranges specified for the thermo-
Inverse functions are provided only for thermocouple pairs and
couple types as given in Tables 1, 2, and 3, and do not apply to
are valid only over the emf ranges specified.
the temperature ranges covered in Tables 8 to 25.
1.9 This specification is intended to define the thermoelec-
1.3 Tables 4 and 5 provide insulation color coding for
tric properties of materials that conform to the relationships
thermocouple and thermocouple extension wires as customar-
presented in the tables of this standard and bear the letter
ily used in the United States.
designations contained herein. Topics such as ordering
1.4 Recommendations regarding upper temperature limits
information, physical and mechanical properties,
for the thermocouple types referred to in 1.1 are provided in
workmanship, testing, and marking are not addressed in this
Table 6.
specification. The user is referred to specific standards such as
Specifications E235, E574, E585/E585M, E608/E608M,
1.5 Tables 26 to 45 give temperature-emf data for single-leg
E1159, or E2181/E2181M for guidance in these areas.
thermoelements referenced to platinum (NIST Pt-67). The
tables include values for Types BP, BN, JP, JN, KP (same as
1.10 The temperature-emf data in this specification are
EP), KN, NP, NN, TP, and TN (same as EN).
intended for industrial and laboratory use.
1.6 Tables for Types RP, RN, SP, and SN thermoelements
1.11 Thermocouple color codes per IEC 584–3 are given in
are not included since, nominally, Tables 18 to 21 represent the
Appendix X1.
thermoelectric properties of Type RP and SP thermoelements
1.12 The values stated in either SI units or inch-pound units
referenced to pure platinum. Tables for the individual thermo-
are to be regarded separately as standard.
1.12.1 The values stated in brackets are not conversions to
the values they succeed and therefore shall be used indepen-
1
This specification is under the jurisdiction of ASTM Committee E20 on
dently of the preceding values.
Temperature Measurement and are the direct responsibility of Subcommittee E20.11
1.12.2 The values given in parentheses are conversions of
on Thermocouples - Calibration.
the values they succeed.
Current edition approved May 1, 2023. Published January 2024. Originally
1.12.3 Combining values from the two systems may result
approved in 1963. Last previous edition approved in 2017 as E230/E230M – 17.
DOI: 10.1520/E0230_E0230M-23.
in non-conformance with the standard.
2
These temperature-emf relationships have been revised as required by the
1.13 This standard does n
...

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: E230/E230M − 17 E230/E230M − 23 An American National Standard
Standard Specification for
Temperature-Electromotive Force (emf) Tables for
1
Standardized Thermocouples
This standard is issued under the fixed designation E230/E230M; 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 specification contains reference tables (Tables 8 to 25) that give temperature-electromotive force (emf) relationships for
2
Types B, C, E, J, K, N, R, S, T, and CT thermocouples. These are the thermocouple types most commonly used in industry. The
tables contain all of the temperature-emf data currently available for the thermocouple types covered by this standard and may
include data outside of the recommended upper temperature limit of an included thermocouple type.
1.2 In addition, the specification includes standard and special tolerances on initial values of emf versus temperature for
thermocouples (Table 1), thermocouple extension wires (Table 2), and compensating extension wires for thermocouples (Table 3).
Users should note that the stated tolerances apply only to the temperature ranges specified for the thermocouple types as given in
Tables 1, 2, and 3, and do not apply to the temperature ranges covered in Tables 8 to 25.
1.3 Tables 4 and 5 provide insulation color coding for thermocouple and thermocouple extension wires as customarily used in the
United States.
1.4 Recommendations regarding upper temperature limits for the thermocouple types referred to in 1.1 are provided in Table 6.
1.5 Tables 26 to 45 give temperature-emf data for single-leg thermoelements referenced to platinum (NIST Pt-67). The tables
include values for Types BP, BN, JP, JN, KP (same as EP), KN, NP, NN, TP, and TN (same as EN).
1.6 Tables for Types RP, RN, SP, and SN thermoelements are not included since, nominally, Tables 18 to 21 represent the
thermoelectric properties of Type RP and SP thermoelements referenced to pure platinum. Tables for the individual thermoelements
of Type C are not included because materials for Type C thermocouples are normally supplied as matched pairs only.
1.7 Polynomial coefficients which may be used for computation of thermocouple emf as a function of temperature are given in
Table 7. Coefficients for the emf of each thermocouple pair as well as for the emf of most individual thermoelements versus
platinum are included. Coefficients for type RP and SP thermoelements are not included since they are nominally the same as for
types R and S thermocouples, and coefficients for type RN or SN relative to the nominally similar Pt-67 would be insignificant.
Coefficients for the individual thermoelements of Type C thermocouples have not been established.
1
This specification is under the jurisdiction of ASTM Committee E20 on Temperature Measurement and are the direct responsibility of Subcommittee E20.11 on
Thermocouples - Calibration.
Current edition approved Nov. 1, 2017May 1, 2023. Published November 2017January 2024. Originally approved in 1963. Last previous edition approved in 20122017
as E230/E230M – 12.E230/E230M – 17. DOI: 10.1520/E0230_E0230M-17.10.1520/E0230_E0230M-23.
2
These temperature-emf relationships have been revised as required by the international adoption in 1989 of a revised International Temperature Scale (ITS-90).
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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E230/E230M − 23
1.8 Coefficients for sets of inverse polynomials are given in Table 46. These may be used for computing a close approximation
of temperature (°C) as a function of thermocouple emf. Inverse functions are provided only for thermocouple pairs and are valid
only over the emf ranges specified.
1.9 This specification is intended to define the thermoelectric properties of materials that conform to the relationships presented
in the tables of this standard and bear the letter designations contained herein. Topics such as ordering information, physical and
mechanical properties, workmanship, testing, and marking are not addressed in this specification. The user is referred to specific
standards such as Specifications E235, E574, E585/E585M, E608/E608M, E1159, or E2181/E2181M for guidance in these areas.
1.10 The temp
...