ASTM E230/E230M-11e1
(Specification)Standard Specification and Temperature-Electromotive Force (emf) Tables for Standardized Thermocouples
Standard Specification and 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, E, J, K, N, R, S, T, and C 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.
1.8 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 specification are ...
General Information
Relations
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
´1
Designation:E230/E230M −11 AnAmerican National Standard
Standard Specification and
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.Anumber in parentheses indicates the year of last reapproval.
A superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1
´ NOTE—Table 46 was changed editorially in October 2011.
1. Scope referenced to pure platinum. Tables for the individual thermo-
elementsofTypeCarenotincludedbecausematerialsforType
1.1 This specification contains reference tables (Tables8 to
C thermocouples are normally supplied as matched pairs only.
25) that give temperature-electromotive force (emf) relation-
2
ships for Types B, E, J, K, N, R, S, T, and C thermocouples. 1.7 Polynomial coefficients which may be used for compu-
These are the thermocouple types most commonly used in tation of thermocouple emf as a function of temperature are
industry. The tables contain all of the temperature-emf data giveninTable7.Coefficientsfortheemfofeachthermocouple
currently available for the thermocouple types covered by this pair as well as for the emf of most individual thermoelements
standard and may include data outside of the recommended versus platinum are included. Coefficients for type RP and SP
upper temperature limit of an included thermocouple type. thermoelements are not included since they are nominally the
same as for types R and S thermocouples, and coefficients for
1.2 In addition, the specification includes standard and
typeRNorSNrelativetothenominallysimilarPt-67wouldbe
special tolerances on initial values of emf versus temperature
insignificant. Coefficients for the individual thermoelements of
for thermocouples (Table1), thermocouple extension wires
Type C thermocouples have not been established.
(Table2), and compensating extension wires for thermo-
couples (Table3). Users should note that the stated tolerances 1.8 Coefficients for sets of inverse polynomials are given in
Table46. These may be used for computing a close approxi-
apply only to the temperature ranges specified for the thermo-
coupletypesasgiveninTables1,2,and3,anddonotapplyto mation of temperature (°C) as a function of thermocouple emf.
Inversefunctionsareprovidedonlyforthermocouplepairsand
the temperature ranges covered in Tables8 to 25.
are valid only over the emf ranges specified.
1.3 Tables 4 and 5 provide insulation color coding for
thermocouple and thermocouple extension wires as customar- 1.9 This specification is intended to define the thermoelec-
ily used in the United States. tric properties of materials that conform to the relationships
presented in the tables of this standard and bear the letter
1.4 Recommendations regarding upper temperature limits
designations contained herein. Topics such as ordering
for the thermocouple types referred to in 1.1 are provided in
information, physical and mechanical properties,
Table6.
workmanship, testing, and marking are not addressed in this
1.5 Tables26to45givetemperature-emfdataforsingle-leg
specification. The user is referred to specific standards such as
thermoelements referenced to platinum (NIST Pt-67). The
Specifications E235, E574, E585/E585M, E608/E608M,
tables include values for Types BP, BN, JP, JN, KP (same as
E1159,or E2181/E2181M for guidance in these areas.
EP), KN, NP, NN, TP, and TN (same as EN).
1.10 The temperature-emf data in this specification are
1.6 Tables for Types RP, RN, SP, and SN thermoelements
intended for industrial and laboratory use.
arenotincludedsince,nominally,Tables18to21representthe
1.11 Thermocouple color codes per IEC 584–3 are given in
thermoelectric properties of Type RP and SP thermoelements
Appendix X1.
1.12 The values stated in either SI units or inch-pound units
1
These tables are under the jurisdiction ofASTM Committee E20 on Tempera-
are to be regarded separately as standard. The values stated in
ture Measurement and are the direct responsibility of Subcommittee E20.04 on
each system may not be exact equivalents; therefore, each
Thermocouples.
system shall be used independently of the other. Combining
Current edition approved May 15, 2011. Published October 2011. Originally
values from the two systems may result in non-conformance
approved in 1963. Last previous edition approved in 2003 as E230–03. DOI:
10.1520/E0230_E0230M-11E01.
with the standard.
2
These temperature-emf relationships have been revised as required by the
1.13 This standard does not purport to address all of the
international adoption in 1989 of a revised International Temperature Scale
(ITS-90). safety concerns, if any, associated with its use. It
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