Thermocouples - Part 1: EMF specifications and tolerances

IEC 60584-1:2013 specifies reference functions and tolerances for letter-designated thermocouples (Types R, S, B, J, T, E, K, N, C and A). Temperatures are expressed in degrees Celsius based on the International Temperature Scale of 1990, ITS-90 (symbol t90), and the EMF (symbol E) is in microvolts. The reference functions are polynomials which express the EMF, E in V, as a function of temperature t90 in °C with the thermocouple reference junctions at 0 °C. Values of EMF at intervals of 1 °C are tabulated in Annex A. This third edition cancels and replaces the second edition published in 1995 and constitutes a technical revision. It includes the following changes: - IEC 60584-1:1995 and IEC 60584-2:1982 have been merged; - the standard is now explicitly based on the reference polynomials which express thermocouple EMF as functions of temperature. The tables derived from the polynomials are given in Annex A; - inverse polynomials expressing temperature as functions of EMF are given in Annex B, but inverse tables are not given; - the range of the polynomial relating the EMF of Type K thermocouples is restricted to 1 300 °C; - values of the Seebeck coefficients are given at intervals of 10 °C; - thermoelectric data (EMF and Seebeck coefficients) are given at the fixed points of the ITS-90; - some guidance is given in Annex C regarding the upper temperature limits and environmental conditions of use for each thermocouple type.

Thermoelemente - Teil 1: Thermospannungen und Grenzabweichungen

Couples thermoélectriques - Partie 1: Spécifications et tolérances en matière de FEM

La CEI 60584-1:2013 spécifie les fonctions de référence et les tolérances associées aux couples thermoélectriques désignés par une lettre (Types R, S, B, J, T, E, K, N, C et A). Les températures y sont exprimées en degrés Celsius selon l'Échelle Internationale de Température de 1990, EIT-90 (symbole t90) et les FEM (symbole E), en microvolts. Les fonctions de référence sont des polynômes qui expriment la FEM, E en V, en fonction de la température t90 en °C, les jonctions de référence des couples thermoélectriques étant placées à 0 °C. L'Annexe A présente, sous forme de tableau, les valeurs de la FEM tous les 1 °C. Cette troisième édition annule et remplace la deuxième édition parue en 1995. Elle constitue une révision technique. Elle inclut les modifications suivantes: - les CEI 60584-1:1995 et CEI 60584-2:1982 ont été fusionnées; - la norme repose désormais de manière explicite sur les polynômes de référence qui expriment la FEM des couples thermoélectriques en fonction de la température. L'Annexe A donne les tables dérivées des polynômes; - l'Annexe B donne les polynômes inverses, qui expriment la température en fonction de la FEM, mais ne donne pas les tables inverses; - le domaine de température du polynôme exprimant la FEM des couples thermoélectriques de Type K est limité à 1 300 °C; - la valeur du coefficient de Seebeck est donnée tous les 10 °C; - les données thermoélectriques (FEM et coefficients de Seebeck) sont fournies aux points fixes de l'EIT-90; - l'Annexe C donne des lignes directrices concernant les limites supérieures de température et les conditions d'environnement lors de l'utilisation de chaque Type de couple thermoélectrique.

Termočleni - 1. del: Specifikacije potencialov (EMF) in tolerance (IEC 60584-1:2013)

Ta del standarda IEC 60584 določa referenčne funkcije in tolerance za termočlene, označene s črkami (tipi R, S, B, J, T, E, K, N, C in A). Temperature so navedene v stopinjah Celzija na podlagi mednarodne temperaturne lestvice iz leta 1990, ITS-90 (simbol t90), EMF (simbol E) pa je naveden v mikrovoltih. Referenčne funkcije so polinomi, ki izražajo EMF, E in μV kot funkcijo temperature t90 v °C z referenčnimi spoji termočlenov pri 0 °C. Vrednosti EMF na enostopinjskih intervalih so tabelirane v Dodatku A. Za pomoč pri računanju temperatur so v Dodatku B podane inverzne funkcije, ki izražajo temperaturo kot funkcijo EMF znotraj podanih mej. Ta mednarodni standard določa tolerance termočlenov, ki so proizvedeni v skladu s tem standardom. Vrednosti toleranc veljajo za termočlene, proizvedene iz žic, običajno s premerom v razponu od 0,13 mm do 3,2 mm, pri čemer se upošteva, da je med uporabo instrument pravilno kalibriran. Dodatek C podaja smernice za izbiro termočlenov glede na temperaturno območje in okoljske pogoje.

General Information

Status
Published
Publication Date
12-Dec-2013
Technical Committee
Drafting Committee
Current Stage
6060 - Document made available
Due Date
02-Jan-2014
Completion Date
13-Dec-2013

RELATIONS

Buy Standard

Standard
EN 60584-1:2014
English language
70 pages
sale 10% off
Preview
sale 10% off
Preview
e-Library read for
1 day

Standards Content (sample)

SLOVENSKI STANDARD
SIST EN 60584-1:2014
01-julij-2014
1DGRPHãþD
SIST EN 60584-1:1998
SIST EN 60584-2:1999

7HUPRþOHQLGHO6SHFLILNDFLMHSRWHQFLDORY (0) LQWROHUDQFH ,(&

Thermocouples - Part 1: EMF specifications and tolerances (IEC 60584-1:2013)
Thermoelemente - Teil 1: Thermospannungen und Grenzabweichungen (IEC 60584-
1:2013)

Couples thermoélectriques - Partie 1: Spécifications et tolérances en matière de FEM

(CEI 60584-1:2013)
Ta slovenski standard je istoveten z: EN 60584-1:2013
ICS:
17.200.20 Instrumenti za merjenje Temperature-measuring
temperature instruments
SIST EN 60584-1:2014 en

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
SIST EN 60584-1:2014
---------------------- Page: 2 ----------------------
SIST EN 60584-1:2014
EUROPEAN STANDARD
EN 60584-1
NORME EUROPÉENNE
December 2013
EUROPÄISCHE NORM
ICS 17.200.20 Supersedes EN 60584-1:1995, EN 60584-2:1993
English version
Thermocouples -
Part 1: EMF specifications and tolerances
(IEC 60584-1:2013)
Couples thermoélectriques - Thermoelemente -
Partie 1: Spécifications et tolérances en Teil 1: Thermospannungen und
matière de FEM Grenzabweichungen
(CEI 60584-1:2013) (IEC 60584-1:2013)

This European Standard was approved by CENELEC on 2013-10-02. CENELEC members are bound to comply

with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard

the status of a national standard without any alteration.

Up-to-date lists and bibliographical references concerning such national standards may be obtained on

application to the CEN-CENELEC Management Centre or to any CENELEC member.

This European Standard exists in three official versions (English, French, German). A version in any other

language made by translation under the responsibility of a CENELEC member into its own language and notified

to the CEN-CENELEC Management Centre has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus,

the Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany,

Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland,

Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Avenue Marnix 17, B - 1000 Brussels

© 2013 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.

Ref. No. EN 60584-1:2013 E
---------------------- Page: 3 ----------------------
SIST EN 60584-1:2014
EN 60584-1:2013 - 2 -
Foreword

The text of document 65B/873/FDIS, future edition 3 of IEC 60584-1, prepared by SC 65B

"Measurement and control devices" of IEC/TC 65 "Industrial-process measurement, control and

automation" was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as

EN 60584-1:2013.
The following dates are fixed:
• latest date by which the document has to be (dop) 2014-07-02
implemented at national level by
publication of an identical national
standard or by endorsement
(dow) 2016-10-02
• latest date by which the national
standards conflicting with the
document have to be withdrawn
This document supersedes EN 60584-1:1995 and EN 60584-2:1993.

EN 60584-1:2013 includes the following significant technical changes with respect to

EN 60584-1:1995 and EN 60584-2:1993:
a) EN 60584-1:1995 and EN 60584-2:1993 have been merged;

b) the standard is now explicitly based on the reference polynomials which express thermocouple

EMF as functions of temperature. The tables derived from the polynomials are given in Annex A;

c) inverse polynomials expressing temperature as functions of EMF are given in Annex B, but inverse

tables are not given;

d) the range of the polynomial relating the EMF of Type K thermocouples is restricted to 1 300 °C;

e) values of the Seebeck coefficients are given at intervals of 10 °C;

f) thermoelectric data (EMF and Seebeck coefficients) are given at the fixed points of the ITS-90;

g) some guidance is given in Annex C regarding the upper temperature limits and environmental

conditions of use for each thermocouple type.

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. CENELEC [and/or CEN] shall not be held responsible for identifying any or all such

patent rights.
Endorsement notice

The text of the International Standard IEC 60584-1:2013 was approved by CENELEC as a European

Standard without any modification.

In the official version, for Bibliography, the following notes have to be added for the standards indicated:

IEC 60584-1:1995 NOTE Harmonized as EN 60584-1:1995 (not modified).
IEC 60584-2:1982 NOTE Harmonized as EN 60584-2:1993 (not modified).
IEC 60584-3:2007 NOTE Harmonized as EN 60584-3:2008 (not modified).
IEC 61515 NOTE Harmonized as EN 61515.
---------------------- Page: 4 ----------------------
SIST EN 60584-1:2014
IEC 60584-1
Edition 3.0 2013-08
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Thermocouples –
Part 1: EMF specifications and tolerances
Couples thermoélectriques –
Partie 1: Spécifications et tolérances en matière de FEM
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX XB
ICS 17.200.20 ISBN 978-2-8322-1047-5

Warning! Make sure that you obtained this publication from an authorized distributor.

Attention! Veuillez vous assurer que vous avez obtenu cette publication via un distributeur agréé.

® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale
---------------------- Page: 5 ----------------------
SIST EN 60584-1:2014
– 2 – 60584-1 © IEC:2013
CONTENTS

FOREWORD ........................................................................................................................... 4

INTRODUCTION ..................................................................................................................... 6

1 Scope ............................................................................................................................... 7

2 Terms and definitions ....................................................................................................... 7

3 Thermocouple designations .............................................................................................. 8

4 EMF – Temperature reference functions ........................................................................... 9

5 Thermocouple tolerances ............................................................................................... 14

6 Thermoelectric values at the fixed points of the ITS-90 ................................................... 15

Annex A (informative) Tables for EMF as a function of temperature ..................................... 17

Annex B (informative) Inverse polynomial functions ............................................................. 57

Annex C (informative) Guidance on the selection of thermocouples ..................................... 64

Bibliography .......................................................................................................................... 68

Table 1 – Thermocouple types ................................................................................................ 9

Table 2 – Type R reference function ..................................................................................... 10

Table 3 – Type S reference function ..................................................................................... 11

Table 4 – Type B reference function ..................................................................................... 11

Table 5 – Type J reference function ...................................................................................... 11

Table 6 – Type T reference function ...................................................................................... 12

Table 7 – Type E reference function ..................................................................................... 12

Table 8 – Type K reference function ..................................................................................... 13

Table 9 – Type N reference function ..................................................................................... 13

Table 10 – Type C reference function ................................................................................... 14

Table 11 – Type A reference function ................................................................................... 14

Table 12 – Thermocouple tolerances .................................................................................... 15

Table 13 – EMF and Seebeck coefficients of the thermocouples at the fixed points of

the ITS-90 (EMF: upper row, Seebeck coefficient: lower row) ............................................... 16

Table A.1 – Type R: Platinum - 13 % rhodium / platinum (1 of 5) .......................................... 17

Table A.2 – Type S: Platinum-10 % rhodium / platinum (1 of 5) ............................................. 21

Table A.3 – Type B: Platinum-30 % rhodium / platinum-6 % rhodium (1 of 4) ........................ 26

Table A.4 – Type J: Iron / copper-nickel (1 of 4) .................................................................... 30

Table A.5 – Type T: Copper / copper-nickel (1 of 2) .............................................................. 34

Table A.6 – Type E: Nickel-chromium / copper-nickel (1 of 3) ............................................... 36

Table A.7 – Type K: Nickel-chromium / nickel-aluminium (1 of 4) .......................................... 39

Table A.8 – Type N: Nickel-chromium-silicon / nickel-silicon (1 of 4) ..................................... 43

Table A.9 – Type C: Tungsten-5 % rhenium / tungsten-26 % rhenium (1 of 5) ....................... 47

Table A.10 – Type A: Tungsten-5 % rhenium / tungsten-20 % rhenium (1 of 5) ..................... 52

Table B.1 – Type R Inverse function coefficients ................................................................... 58

Table B.2 – Type S Inverse function coefficients ................................................................... 59

Table B.3 – Type B Inverse function coefficients ................................................................... 59

Table B.4 – Type J Inverse function coefficients ................................................................... 60

Table B.5 – Type T Inverse function coefficients ................................................................... 60

---------------------- Page: 6 ----------------------
SIST EN 60584-1:2014
60584-1 © IEC:2013 – 3 –

Table B.6 – Type E Inverse function coefficients ................................................................... 61

Table B.7 – Type K Inverse function coefficients ................................................................... 61

Table B.8 – Type N Inverse function coefficients ................................................................... 62

Table B.9 – Type C Inverse function coefficients ................................................................... 62

Table B.10 – Type A Inverse function coefficients ................................................................. 63

Table C.1 – Recommended maximum temperature of use, t / °C ..................................... 64

max

Table C.2 – Environmental recommendations and limitations of the conductors .................... 66

Table C.3 – Neutron irradiation effects .................................................................................. 67

---------------------- Page: 7 ----------------------
SIST EN 60584-1:2014
– 4 – 60584-1 © IEC:2013
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
THERMOCOUPLES –
Part 1: EMF specifications and tolerances
FOREWORD

1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising

all national electrotechnical committees (IEC National Committees). The object of IEC is to promote

international co-operation on all questions concerning standardization in the electrical and electronic fields. To

this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,

Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC

Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested

in the subject dealt with may participate in this preparatory work. International, governmental and non-

governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely

with the International Organization for Standardization (ISO) in accordance with conditions determined by

agreement between the two organizations.

2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international

consensus of opinion on the relevant subjects since each technical committee has representation from all

interested IEC National Committees.

3) IEC Publications have the form of recommendations for international use and are accepted by IEC National

Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC

Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any

misinterpretation by any end user.

4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications

transparently to the maximum extent possible in their national and regional publications. Any divergence

between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in

the latter.

5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity

assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any

services carried out by independent certification bodies.

6) All users should ensure that they have the latest edition of this publication.

7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and

members of its technical committees and IEC National Committees for any personal injury, property damage or

other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and

expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC

Publications.

8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is

indispensable for the correct application of this publication.

9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of

patent rights. IEC shall not be held responsible for identifying any or all such patent rights.

International Standard IEC 60584-1 has been prepared by sub-committee 65B: Measurement

and control devices, of IEC technical committee 65: Industrial-process measurement,control

and automation.

This third edition cancels and replaces the second edition published in 1995. This edition

constitutes a technical revision.

This edition includes the following significant technical changes with respect to the previous

edition:
a) IEC 60584-1:1995 and IEC 60584-2:1982 have been merged;

b) the standard is now explicitly based on the reference polynomials which express

thermocouple EMF as functions of temperature. The tables derived from the polynomials

are given in Annex A;

c) inverse polynomials expressing temperature as functions of EMF are given in Annex B, but

inverse tables are not given;
---------------------- Page: 8 ----------------------
SIST EN 60584-1:2014
60584-1 © IEC:2013 – 5 –

d) the range of the polynomial relating the EMF of Type K thermocouples is restricted to

1 300 °C;
e) values of the Seebeck coefficients are given at intervals of 10 °C;

f) thermoelectric data (EMF and Seebeck coefficients) are given at the fixed points of the

ITS-90;
g) some guidance is given in Annex C regarding the upper temperature limits and
environmental conditions of use for each thermocouple type.
The text of this standard is based on the following documents:
FDIS Report on voting
65B/873/FDIS 65B/888/RVD

Full information on the voting for the approval of this standard can be found in the report on

voting indicated in the above table.

This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.

A list of all parts of the IEC 60584 series, under the general title Thermocouples can be found

on the IEC website.

The committee has decided that the contents of this publication will remain unchanged until

the stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data

related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
---------------------- Page: 9 ----------------------
SIST EN 60584-1:2014
– 6 – 60584-1 © IEC:2013
INTRODUCTION

This International Standard relates the electromotive force (hereafter abbreviated as EMF)

generated by the designated thermocouple types to temperature, based upon the International

Temperature Scale of 1990 (ITS-90).

The reference polynomials for Types R, S, B, J, T, E, K and N are those used in the previous

edition of this standard, IEC 60584-1:1995 . They were originally produced by the National

Institute of Standards and Technology of the USA and published in NIST Monograph 175,

1993.

The major revision of this version is standardization of two kinds of tungsten-rhenium

thermocouple, designated Type C and Type A. Both of them have been used in industry for a

long time. Temperature versus EMF relationships for Type C and Type A are those published

in the ASTM E230/E230-M12 and GOST R 8.585-2001 standards, respectively.

This edition merges two parts of the former IEC 60584 series, IEC 60584-1:1995 (Reference

tables) and IEC 60584-2:1982 (Tolerances) and supersedes both standards.
IEC 60584-3:2007 remains valid.
—————————
See Bibliography.
---------------------- Page: 10 ----------------------
SIST EN 60584-1:2014
60584-1 © IEC:2013 – 7 –
THERMOCOUPLES –
Part 1: EMF specifications and tolerances
1 Scope

This part of IEC 60584 specifies reference functions and tolerances for letter-designated

thermocouples (Types R, S, B, J, T, E, K, N, C and A). Temperatures are expressed in

degrees Celsius based on the International Temperature Scale of 1990, ITS-90 (symbol t ),

and the EMF (symbol E) is in microvolts.

The reference functions are polynomials which express the EMF, E in µV, as a function of

temperature t in °C with the thermocouple reference junctions at 0 °C. Values of EMF at

intervals of 1 °C are tabulated in Annex A.

For convenience of calculating temperatures, inverse functions are given in Annex B which

express temperature as functions of EMF within stated accuracies.

This International Standard specifies the tolerances for thermocouples manufactured in

accordance with this standard. The tolerance values are for thermocouples manufactured

from wires, normally in the diameter range 0,13 mm to 3,2 mm, as delivered to the user and

do not allow for calibration drift during use.

Annex C gives guidance on the selection of thermocouples with regard to temperature range

and environmental conditions.
2 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
2.1
thermoelectric effect
Seebeck effect

production of an electromotive force (EMF) due to a temperature gradient along a conductor

2.2
Seebeck coefficient of a thermocouple

change in EMF of a thermocouple combination per unit of temperature change, being the first

derivative of EMF with respect to temperature.
Note 1 to entry: The Seebeck coefficient dE/dt , is expressed in µV/°C.
2.3
thermocouple

pair of conductors of dissimilar materials joined at one end and forming part of an

arrangement using the thermoelectric effect for temperature measurement
2.4
measuring junction
junction of the thermocouple subjected to the temperature to be measured
---------------------- Page: 11 ----------------------
SIST EN 60584-1:2014
– 8 – 60584-1 © IEC:2013
2.5
reference junction
junction of the thermocouple at a known (reference) temperature

Note 1 to entry: For the specified EMFs of this standard, the reference temperature is 0 °C.

2.6
tolerance

maximum initial permissible deviation from the EMF specification of this standard

Note 1 to entry: The tolerance is expressed as the temperature equivalent in degrees Celsius Celsius (°C).

3 Thermocouple designations

When a thermocouple is identified by the materials of its conductors, the positive conductor

shall be listed first, thus: ‘positive conductor / negative conductor’.

The positive conductor is the conductor having a positive electric potential with respect to the

other conductor when the measuring junction is at a higher temperature than the reference

junction.

Table 1 lists the thermocouple types for which EMFs are specified in this standard. Each letter

designation of the table identifies the EMF-temperature reference function in the Tables 2 to

11. The designation may be applied to any thermocouple conforming to the relevant function

within the stated tolerances specified in Clause 5, regardless of its composition.

Conformity with alloy specification listed in this clause does not guarantee conformity with the

EMF-temperature relationship of this standard.
---------------------- Page: 12 ----------------------
SIST EN 60584-1:2014
60584-1 © IEC:2013 – 9 –
Table 1 – Thermocouple types
Letter Elements and nominal alloy compositions by weight
designation Positive conductor Negative conductor
R Platinum – 13 % rhodium Platinum
S Platinum – 10 % rhodium Platinum
B Platinum – 30 % rhodium Platinum – 6 % rhodium
J Iron Copper – nickel
T Copper Copper – nickel
E Nickel – chromium Copper – nickel
K Nickel – chromium Nickel – aluminium
N Nickel – chromium – silicon Nickel – silicon
C Tungsten – 5 % rhenium Tungsten – 26 % rhenium
A Tungsten – 5 % rhenium Tungsten – 20 % rhenium
NOTE

– Standard alloy compositions have not been established for base metal thermocouple alloys except Type N,

but it should be noted that the compositions are not so critical as the matching of the positive and negative

conductor. In particular, the negative conductor of Type J, Type E and Type T thermocouples are generally

not interchangeable with each other. Likewise positive conductors of Type C and A are not necessary

interchangeable.

– For Type N thermocouple the following composition (percentages of total by weight) is recommended in

order to obtain the desired properties like good stability and oxidation resistance.

Positive conductor (known as Nicrosil): 13,7% to 14,7 % Cr%, 1,2 to 1,6 % Si, less than 0,15 % Fe, less than

0,05 % C, less than 0,01 % Mg, balance Ni.

Negative conductor (known as Nisil): less than 0,02 % Cr, 4,2 % to 4,6 % Si, less than 0,15 % Fe, less than

0,05 % C, 0,0 5% to 0,2 % Mg, balance Ni.
4 EMF – Temperature reference functions

The temperature and EMF relationships of this standard are defined by reference functions

which give EMF, E/µV, as a function of the temperature, t /°C, with a reference temperature

of 0 °C.

The reference function of polynomial form for each type of thermocouple, except for Type K in

the temperature range from 0 °C to 1 300 °C, is defined by the following equation.

E = a ×(t )
(1)
i 90
i =0
where
E is EMF, expressed in microvolts (µV);
t is ITS-90 temperature, expressed in degrees Celsius (°C);
a is the i coefficient of the polynomial;
n is the order of the polynomial.
and n are dependent on the type of thermocouple and temperature range.
The values of a
Those for each thermocouple are given in the Tables 2 to 11.
---------------------- Page: 13 ----------------------
SIST EN 60584-1:2014
– 10 – 60584-1 © IEC:2013

For the Type K in the temperature range from 0 °C to 1 300 °C, the reference function is

defined by the following equation.
i 2
E = a × (t ) + c × exp[c × (t − 126,968 6) ]
(2)
i 90 0 1 90
i =0
where
E is EMF, expressed in microvolts (µV);
t is ITS-90 temperature, expressed in degrees Celsius (°C);
a is the i coefficient of the polynomial;
n is the order of the polynomial;
c c are constants given in Table 8.
0, 1
Values of EMF are tabulated at intervals of 1 °C in Annex A.

Annex B gives inverse functions relating temperature to EMF within stated accuracies.

NOTE 1 Depending on the processing power available, rounding errors may arise in the calculations using these

polynomials. This can be avoided by using the technique of nested multiplication. Thus, form the product a t, add

a , multiply the result by t, etc, continuing through the series, finally adding a to obtain the result:

(n-1) 0
E = (..((a ⋅ t + a ) ⋅ t + a ) ⋅ t + ... + a ) ⋅ t + a
n 90 (n−1) 90 (n−2) 90 1 90 0
Table 2 – Type R reference function
Polynomial Temperature range

coefficient –50 °C to 1 064,18 °C ( n = 9 ) 1 064,18 °C to 1 664,5 °C ( n = 5 ) 1 664,5 °C to 1 768,1 °C ( n = 4 )

0 3 5
a 0,000 000 000 00 × 10 2,951 579 253 16 × 10 1,522 321 182 09 × 10
0 0 2
a 5,289 617 297 65 × 10 –2,520 612 513 32 × 10 –2,688 198 885 45 × 10
–2 –2 –1
a 1,391 665 897 82 × 10 1,595 645 018 65 × 10 1,712 802 804 71 × 10
–5 –6 –5
a –2,388 556 930 17 × 10 –7,640 859 475 76 × 10 –3,458 957 064 53 × 10
–8 –9 –12
a 3,569 160 010 63 × 10 2,053 052 910 24 × 10 –9,346 339 710 46 × 10
–11 –13
a –4,623 476 662 98 × 10 –2,933 596 681 73 × 10
–14
- -
a 5,007 774 410 34 × 10
–17
- -
a –3,731 058 861 91 × 10
–20
a 1,577 164 823 67 × 10 - -
–24
a –2,810 386 252 51 × 10 - -
---------------------- Page: 14 ----------------------
SIST EN 60584-1:2014
60584-1 © IEC:2013 – 11 –
Table 3 – Type S reference function
Polynomial Temperature range

coefficient –50 °C to 1 064,18 °C ( n = 8 ) 1 064,18 °C to 1 664,5 °C ( n = 4 ) 1 664,5 °C to 1 768,1 °C ( n = 4 )

0 3 5
a 0,000 000 000 00 × 10 1,329 004 440 85 × 10 1,466 282 326 36 × 10
0 0 2
a 5,403 133 086 31 × 10 3,345 093 113 44 × 10 –2,584 305 167 52 × 10
–2 –3 –1
a 1,259 342 897 40 × 10 6,548 051 928 18 × 10 1,636 935 746 41 × 10
–5 –6 –5
a –2,324 779 686 89 × 10 –1,648 562 592 09 × 10 –3,304 390 469 87 × 10
–8 –11 –12
a 3,220 288 230 36 × 10 1,299 896 051 74 × 10 –9,432 236 906 12 × 10
–11
- -
a –3,314 651 963 89 × 10
–14
a 2,557 442 517 86 × 10 - -
–17
a –1,250 688 713 93 × 10 - -
–21
a 2,714 431 761 45 × 10 - -
Table 4 – Type B reference function
Polynomial Temperature range
coefficient 0 °C to 630,615 °C ( n = 6 ) 630,615 °C to 1 820 °C ( n = 8 )
0 3
a 0,000 000 000 00 × 10 –3,893 816 862 1 × 10
–1 1
a –2,465 081 834 6 × 10 2,857 174 747 0 × 10
–3 –2
a 5,904 042 117 1 × 10 –8,488 510 478 5 × 10
–6 –4
a –1,325 793 163 6 × 10 1,578 528 016 4 × 10
–9 –7
a 1,566 829 190 1 × 10 –1,683 534 486 4 × 10
–12 –10
a –1,694 452 924 0 × 10 1,110 979 401 3 × 10
–16 –14
a 6,299 034 709 4 × 10 –4,451 543 103 3 × 10
–18
a - 9,897 564 082 1 × 10
–22
a –9,379 133 028 9 × 10
Table 5 – Type J reference function
Polynomial Temperature range
coefficient –210 °C to 760 °C ( n = 8 ) 760 °C to 1 200 °C ( n = 5 )
0 5
a 0,000 000 000 0 × 10 2,964 562 568 1 × 10
1 3
a 5,038 118 781 5 × 10 –1,497 612 778 6 × 10
–2 0
a 3,047 583 693 0 × 10 3,178 710 392 4 × 10
–5 –3
a –8,568 106 572 0 × 10 –3,184 768 670 1 × 10
–7 –6
a 1,322 819 529 5 × 10 1,572 081 900 4 × 10
–10 –10
a –1,705 295 833 7 × 10 –3,069 136 905 6 × 10
–13
a 2,094 809 069 7 × 10
–16
a –1,253 839 533 6 × 10 -
–20
a 1,563 172 569 7 × 10 -

The specified function for Type J (Table 5) extends up to 1 200 °C; however, it should be

noted that when a Type J thermocouple has been used above 760 °C, its performance below

760 °C may not conform to the lower part of the function within specified tolerances.

---------------------- Page: 15 ----------------------
SIST EN 60584-1:2014
– 12 – 60584-1 © IEC:2013
Table 6 – Type T reference function
Polynomial Temperature range
coefficient –270 °C to 0 °C ( n = 14 ) 0 °C to 400 °C ( n = 8 )
0 0
a 0,000 000 000 0 × 10 0,000 000 000 0 × 10
1 1
a 3,874 810 636 4 × 10 3,874 810 636 4 × 10
–2 –2
a 4,419 443 434 7 × 10 3,329 222 788 0 × 10
–4 –4
a 1,184 432 310 5 × 10 2,061 824 340 4 × 10
–5 –6
a 2,003 297 355 4 × 10 –2,188 225 684 6 × 10
–7 –8
a 9,013 801 955 9 × 10 1,099 688 092 8 × 10
–8 –11
a 2,265 115 659 3 × 10 –3,081 575 877 2 × 10
–10 –14
a 3,607 115 420 5 × 10 4,547 913 529 0 × 10
–12 –17
a 3,849 393 988 3 × 10 –2,751 290 167 3 × 10
–14
a 2,821
...

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.