ASTM E230-98e1

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

SCOPE
1.1 This specification contains reference tables (Tables 8-23) that give temperature-electromotive force (emf) relationships for Types B, E, J, K, N, R, S, and T thermocouples. These are the thermocouple types most commonly used in industry.
1.2 Also included are lists of 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).
1.3 Tables 4-5, included herein, give data on 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 given in Table 6.
1.5 Tables 24-43 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 18-21 represent the thermoelectric properties of Type RP and SP thermoelements referenced to pure platinum.
1.7 Polynomial coefficients that 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 individual thermoelements versus platinum are included.
1.8 Coefficients for sets of inverse polynomials are given in Table 44. These may be used for computing a close approximation of temperature (oC) 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, E608, E1159, or E1223, as appropriate, for guidance in these areas.
1.10 The temperature-emf data in this specification are intended for industrial and laboratory use.

General Information

• Status: Historical
• Publication Date: 09-Jun-1998
• ICS: 17.200.20 - Temperature-measuring instruments
• Technical Committee: E20 - Temperature Measurement

Relations

• Replaced By: ASTM E230-03 - Standard Specification and Temperature-Electromotive Force (EMF) Tables for Standardized Thermocouples
• Effective Date: 23-Sep-2003

Standards Content (Sample)

An American National Standard
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Designation: E 230 – 98
Standard Specification and
Temperature-Electromotive Force (EMF) Tables for
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Standardized Thermocouples
This standard is issued under the fixed designation E 230; 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 (e) indicates an editorial change since the last revision or reapproval.
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e NOTE—Table 44, under Type K Thermocouple, was editorially corrected to match the E 230–96 version.
1. Scope 1.9 This specification is intended to define the thermoelec-
tric properties of materials that conform to the relationships
1.1 This specification contains reference tables (Tables
presented in the tables of this standard and bear the letter
8–23) that give temperature-electromotive force (emf) relation-
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designations contained herein. Topics such as ordering infor-
ships for Types B, E, J, K, N, R, S, and T thermocouples.
mation, physical and mechanical properties, workmanship,
These are the thermocouple types most commonly used in
testing, and marking are not addressed in this specification. The
industry.
user is referred to specific standards such as Specifications
1.2 Also included are lists of standard and special tolerances
E 235, E 574, E 585, E 608, E 1159, or E 1223, as appropriate,
on initial values of emf versus temperature for thermocouples
for guidance in these areas.
(Table 1), thermocouple extension wires (Table 2), and com-
1.10 The temperature-emf data in this specification are
pensating extension wires for thermocouples (Table 3).
intended for industrial and laboratory use.
1.3 Tables 4–5, included herein, give data on insulation
color coding for thermocouple and thermocouple extension
2. Referenced Documents
wires as customarily used in the United States.
2.1 ASTM Standards:
1.4 Recommendations regarding upper temperature limits
E 235 Specification for Thermocouples, Sheathed, Type K,
for the thermocouple types referred to in 1.1 are given in Table
3
for Nuclear or for Other High-Reliability Applications
6.
E 574 Specification for Duplex, Base-Metal Thermocouple
1.5 Tables 24–43 give temperature-emf data for single-leg
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Wire with Glass Fiber or Silica Fiber Insulation
thermoelements referenced to platinum (NIST Pt 67). The
E 585 Specification for Sheathed Base-Metal Thermo-
tables include values for Types BP, BN, JP, JN, KP (same as
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couple Materials
EP), KN, NP, NN, TP, and TN (same as EN).
E 608 Specification for Metal-Sheathed Base-Metal Ther-
1.6 Tables for Types RP, RN, SP, and SN thermoelements
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mocouples
are not included since, nominally, Tables 18–21 represent the
E 1159 Specification for Thermocouple Materials,
thermoelectric properties of Type RP and SP thermoelements
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Platinum-Rhodium Alloys, and Platinum
referenced to pure platinum.
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E 1223 Specification for Type N Thermocouple Wire
1.7 Polynomial coefficients that may be used for computa-
2.2 NIST Monograph:
tion of thermocouple emf as a function of temperature are
NIST Monograph 175 Temperature-Electromotive Force
given in Table 7. Coefficients for the emf of each thermocouple
Reference Functions and Tables for the Letter-Designated
pair as well as for the emf of individual thermoelements versus
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Thermocouple Types Based on the ITS-90
platinum are included.
2.3 IEC Standard:
1.8 Coefficients for sets of inverse polynomials are given in
IEC 584–3 First edition, 1989
Table 44. These may be used for computing a close approxi-
mation of temperature (°C) as a function of thermocouple emf.
3. Source of Data
Inverse functions are provided only for thermocouple pairs and
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3.1 The data in these tables are based upon the SI volt and
are valid only over the emf ranges specified.
the International Temperature Scale of 1990.
3.2 The temperature-emf data in Tables 8–43 and the
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These tables are under the jurisdiction of ASTM Committee E-20 on Tempera-
ture Measurement and are the direct responsibility of Subcommittee E20.04 on
Thermocouples.
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Current edition approved June 10, 1998. Published March 1999. Originally Annual Book of ASTM Standards, Vol 14.03.
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published as E 230 – 63. Last previous edition E 230 – 96 . Available from National Institute of Standards and Technology, U.S. Depart-
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These temperature-emf relationships have been revised as required by the ment of Commerce, Gaithersburg, MD 20899.
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international adoption in 1989 of a revised International Temperature Scale Discussed in NIST Technical Note 1263, Guidelines for Implementing the New
(ITS-90). Representations of the Volt and Ohm Effective January 1, 1990.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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E 230
corresponding equations in Tables 7 and 44 for all of the within the stated tolerances.
thermocouple types ha
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