Industrial platinum resistance thermometers and platinum temperature sensors (IEC 60751:2022)

This International Standard specifies the requirements, in addition to the resistance versus
temperature relationship, for both industrial platinum resistance thermometers (later referred to
as "thermometers") and industrial platinum resistance temperature sensors (later referred to as
"platinum resistors") whose electrical resistance is derived from defined functions of
temperature.
Values of temperature in this document are in terms of the International Temperature Scale of
1990, ITS-90. A temperature in the unit °C of this scale is denoted by the symbol t, except in
Table A.1 where the full nomenclature t90 /°C is used.
This document applies to platinum resistors whose temperature coefficient α, defined as
is conventionally written as α = 3,851⋅10-3 °C-1, where R100 is the resistance at t = 100 °C and R0 is the resistance at t = 0 °C.
This document covers platinum resistors and thermometers for the temperature range −200 °C
to +850 °C with different tolerance classes. It can also cover particular platinum resistors or
thermometers for a part of this temperature range.
For resistance versus temperature relationships with uncertainties less than 0,1 °C, which are
possible only for platinum resistors or thermometers with exceptionally high stability and
individual calibration, a more complex interpolation equation than is presented in this document
can be necessary. The specification of such equations is outside the scope of this document.

Industrielle Platin-Widerstandsthermometer und Platin-Temperatursensoren (IEC 60751:2022)

Thermomètres à résistance de platine industriels et capteurs thermométriques en platine (IEC 60751:2022)

L'IEC 60751:2022 spécifie les exigences en plus de la relation entre la température et la résistance pour les thermomètres à résistance de platine industriels (dénommés ci-après "thermomètres") et les capteurs thermométriques de platine industriels (dénommés ci-après "résistances de platine") dont la résistance électrique est dérivée de fonctions définies de la température. Les valeurs de température données dans le présent document sont exprimées en accord avec l’Échelle Internationale de Température de 1990, EIT-90, en °C, et par le symbole t, à l’exception du Tableau A.1 où l’expression t90/°C est utilisée.

Industrijski uporovni termometri in temperaturni senzorji iz platine (IEC 60751:2022)

Ta mednarodni standard, poleg razmerja med upornostjo in temperaturo, določa zahteve za industrijske uporovne termometre (v nadaljevanju »termometre«) in temperaturne senzorje iz platine (v nadaljevanju »senzorji iz platine«), katerih električna upornost izhaja iz definiranih funkcij temperature.
Vrednosti temperature v tem dokumentu so podane glede na mednarodno temperaturno lestvico iz leta 1990, ITS-90. Temperatura v enotah °C te lestvice je označena s simbolom t, razen v preglednici A.1, kjer se uporablja celotna nomenklatura t90/°C.
Ta dokument se uporablja za senzorje iz platine, katerih temperaturni koeficient je α, opredeljen in običajno zapisan kot α = 3,851⋅10-3 °C-1, kjer je R100 upor pri t = 100 °C in R0 je upor pri t = 0 °C.
Ta dokument zajema senzorje iz platine in termometre za temperaturno območje −200 °C do 850 °C z različnimi tolerančnimi razredi. Zajema lahko tudi določene senzorje iz platine ali termometre za del tega temperaturnega območja.
Za razmerja med upornostjo in temperaturo z negotovostmi manj kot 0,1 °C, ki so možna samo za senzorje iz platine ali termometre z izjemno visoko stabilnostjo in individualno kalibracijo, je morda potrebna kompleksnejša interpolacijska enačba, kot je predstavljena v tem dokumentu. Specifikacija takih enačb ne spada na področje uporabe tega dokumenta.

General Information

Status
Published
Public Enquiry End Date
15-Mar-2021
Publication Date
03-May-2022
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
09-Mar-2022
Due Date
14-May-2022
Completion Date
04-May-2022

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Standards Content (sample)

SLOVENSKI STANDARD
SIST EN IEC 60751:2022
01-junij-2022
Nadomešča:
SIST EN 60751:2009
Industrijski uporovni termometri in temperaturni senzorji iz platine (IEC
60751:2022)

Industrial platinum resistance thermometers and platinum temperature sensors (IEC

60751:2022)
Industrielle Platin-Widerstandsthermometer und Platin-Temperatursensoren (IEC
60751:2022)

Thermomètres à résistance de platine industriels et capteurs thermométriques en platine

(IEC 60751:2022)
Ta slovenski standard je istoveten z: EN IEC 60751:2022
ICS:
17.200.20 Instrumenti za merjenje Temperature-measuring
temperature instruments
SIST EN IEC 60751:2022 en,fr,de

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

---------------------- Page: 1 ----------------------
SIST EN IEC 60751:2022
---------------------- Page: 2 ----------------------
SIST EN IEC 60751:2022
EUROPEAN STANDARD EN IEC 60751
NORME EUROPÉENNE
EUROPÄISCHE NORM March 2022
ICS 17.200.20 Supersedes EN 60751:2008 and all of its amendments
and corrigenda (if any)
English Version
Industrial platinum resistance thermometers and platinum
temperature sensors
(IEC 60751:2022)

Thermomètres à résistance de platine et capteurs Industrielle Platin-Widerstandsthermometer und Platin-

thermométriques de platine industriels Temperatursensoren
(IEC 60751:2022) (IEC 60751:2022)

This European Standard was approved by CENELEC on 2022-03-03. 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, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the

Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,

Turkey and the United Kingdom.
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels

© 2022 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.

Ref. No. EN IEC 60751:2022 E
---------------------- Page: 3 ----------------------
SIST EN IEC 60751:2022
EN IEC 60751:2022 (E)
European foreword

The text of document 65B/1210/FDIS, future edition 3 of IEC 60751, 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 IEC 60751:2022.
The following dates are fixed:

• latest date by which the document has to be implemented at national (dop) 2022-12-03

level by publication of an identical national standard or by endorsement

• latest date by which the national standards conflicting with the (dow) 2025-03-03

document have to be withdrawn

This document supersedes EN 60751:2008 and all of its amendments and corrigenda (if any).

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

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

Any feedback and questions on this document should be directed to the users’ national committee. A

complete listing of these bodies can be found on the CENELEC website.
Endorsement notice

The text of the International Standard IEC 60751:2022 was approved by CENELEC as a European

Standard without any modification.

In the official version, for Bibliography, the following note has to be added for the standard indicated:

IEC 61298-1 NOTE Harmonized as EN 61298-1
---------------------- Page: 4 ----------------------
SIST EN IEC 60751:2022
EN IEC 60751:2022 (E)
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications

The following documents are referred to in the text in such a way that some or all of their content

constitutes requirements of this document. For dated references, only the edition cited applies. For

undated references, the latest edition of the referenced document (including any amendments)

applies.

NOTE 1 Where an International Publication has been modified by common modifications, indicated by (mod), the

relevant EN/HD applies.

NOTE 2 Up-to-date information on the latest versions of the European Standards listed in this annex is available

here: www.cenelec.eu.
Publication Year Title EN/HD Year
IEC 60068-2-6 - Environmental testing - Part 2-6: Tests - EN 60068-2-6 -
Test Fc: Vibration (sinusoidal)
IEC 61152 - Dimensions of metal-sheathed EN 61152 -
thermometer elements
IEC 61515 2016 Mineral insulated metal-sheathed EN 61515 2016
thermocouple cables and thermocouples
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SIST EN IEC 60751:2022
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SIST EN IEC 60751:2022
IEC 60751
Edition 3.0 2022-01
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Industrial platinum resistance thermometers and platinum temperature sensors
Thermomètres à résistance de platine et capteurs hermométriques de platine
industriels
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 17.200.20 ISBN 978-2-8322-1069-2

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: 7 ----------------------
SIST EN IEC 60751:2022
– 2 – IEC 60751:2022 © IEC 2022
CONTENTS

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

1 Scope .............................................................................................................................. 6

2 Normative references ...................................................................................................... 6

3 Terms and definitions ...................................................................................................... 7

4 Characteristics ................................................................................................................ 8

4.1 General ................................................................................................................... 8

4.2 Nominal resistance versus temperature relationship ............................................... 9

4.3 Numerical table of resistance values ....................................................................... 9

5 Compliance and requirements ......................................................................................... 9

5.1 Compliance ............................................................................................................. 9

5.2 Tolerance classes ................................................................................................. 10

5.2.1 Tolerance class and its temperature range of validity ..................................... 10

5.2.2 Tolerance class of platinum resistors ............................................................. 10

5.2.3 Tolerance classes and marking of thermometers ........................................... 10

5.3 Measuring current ................................................................................................. 12

5.4 Electrical supply .................................................................................................... 12

5.5 Connecting wire configuration ............................................................................... 12

6 Tests ............................................................................................................................. 13

6.1 General ................................................................................................................. 13

6.1.1 Test categories .............................................................................................. 13

6.1.2 Routine production tests ................................................................................ 13

6.1.3 Type tests ...................................................................................................... 13

6.1.4 Additional type tests for thermometers ........................................................... 14

6.1.5 Summary of the tests ..................................................................................... 14

6.2 Routine production tests for platinum resistors ...................................................... 14

6.2.1 Tolerance acceptance test ............................................................................. 14

6.3 Routine production tests for thermometers ............................................................ 15

6.3.1 Tolerance acceptance test ............................................................................. 15

6.3.2 Insulation resistance at ambient temperature ................................................. 16

6.3.3 Sheath integrity test ....................................................................................... 16

6.3.4 Dimensional test ............................................................................................ 16

6.4 Type tests for platinum resistors ........................................................................... 16

6.4.1 Tolerances .................................................................................................... 16

6.4.2 Stability at upper temperature limit ................................................................ 17

6.4.3 Self-heating ................................................................................................... 17

6.5 Type tests for thermometers ................................................................................. 17

6.5.1 Tolerances .................................................................................................... 17

6.5.2 Stability at upper temperature limit ................................................................ 17

6.5.3 Self-heating ................................................................................................... 17

6.5.4 Insulation resistance at elevated temperature ................................................ 17

6.5.5 Thermal response time .................................................................................. 18

6.5.6 Thermoelectric effect ..................................................................................... 18

6.5.7 Effect of temperature cycling ......................................................................... 18

6.5.8 Effect of hysteresis ........................................................................................ 18

6.5.9 Minimum immersion depth ............................................................................. 18

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SIST EN IEC 60751:2022
IEC 60751:2022 © IEC 2022 – 3 –

6.6 Additional type tests for thermometers .................................................................. 19

6.6.1 General ......................................................................................................... 19

6.6.2 Capacitance .................................................................................................. 19

6.6.3 Inductance ..................................................................................................... 19

6.6.4 Dielectric strength .......................................................................................... 19

6.6.5 Vibration test ................................................................................................. 19

6.6.6 Drop test ....................................................................................................... 19

6.6.7 Cold seal ....................................................................................................... 19

7 Information to be made available by the supplier ........................................................... 19

7.1 General ................................................................................................................. 19

7.2 Applicable to resistors ........................................................................................... 20

7.3 Applicable to thermometers ................................................................................... 20

Annex A (informative) Numerical table ................................................................................. 21

Bibliography .......................................................................................................................... 25

Figure 1 – Example of connecting configurations .................................................................. 13

Figure 2 – Examples of test results for selecting or rejecting platinum resistors .................... 15

Table 1 – Tolerance class of platinum resistors..................................................................... 10

Table 2 – Tolerance class of thermometers ........................................................................... 11

Table 3 – Table of tests specified in this document ............................................................... 14

Table 4 – Minimum insulation resistance of thermometers at the maximum temperature ....... 17

Table A.1 – Temperature versus resistance relationship below 0 °C; R = 100,00 Ω ............. 21

Table A.2 – Temperature versus resistance relationship above 0 °C; R = 100,00 Ω ............. 22

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SIST EN IEC 60751:2022
– 4 – IEC 60751:2022 © IEC 2022
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
INDUSTRIAL PLATINUM RESISTANCE THERMOMETERS
AND PLATINUM TEMPERATURE SENSORS
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.

IEC 60751 has been prepared by subcommittee 65B: Measurement and control devices, of IEC

technical committee 65: Industrial-process measurement, control and automation. It is an

International Standard.

This third edition cancels and replaces the second edition published in 2008. This edition

constitutes a technical revision.

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

edition:

a) formula of resistance versus temperature relationship become the standard specification

and the numerical table ceases to be the standard,
b) new clause "Compliance and requirement" is introduced,
c) tolerance acceptance test is modified,

d) an expanded marking system is introduced to accommodate special valid temperature

range,
e) vibration test method is revised,
f) cold seal is introduced as an additional type test,
---------------------- Page: 10 ----------------------
SIST EN IEC 60751:2022
IEC 60751:2022 © IEC 2022 – 5 –

g) numerical table of resistance versus temperature is included in Annex A as information.

The text of this International Standard is based on the following documents:
Draft Report on voting
65B/1210/FDIS 65B/1214/RVD

Full information on the voting for its approval can be found in the report on voting indicated in

the above table.
The language used for the development of this International Standard is English.

This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in

accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available

at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are

described in greater detail at www.iec.ch/standardsdev/publications.

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

stability date indicated on the IEC website under webstore.iec.ch in the data related to the

specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
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SIST EN IEC 60751:2022
– 6 – IEC 60751:2022 © IEC 2022
INDUSTRIAL PLATINUM RESISTANCE THERMOMETERS
AND PLATINUM TEMPERATURE SENSORS
1 Scope

This International Standard specifies the requirements, in addition to the resistance versus

temperature relationship, for both industrial platinum resistance thermometers (later referred to

as "thermometers") and industrial platinum resistance temperature sensors (later referred to as

"platinum resistors") whose electrical resistance is derived from defined functions of

temperature.

Values of temperature in this document are in terms of the International Temperature Scale of

1990, ITS-90. A temperature in the unit °C of this scale is denoted by the symbol t, except in

Table A.1 where the full nomenclature t /°C is used.

This document applies to platinum resistors whose temperature coefficient α, defined as

RR−
100 0
α = ,
R ⋅°100 C
-3 -1

is conventionally written as α = 3,851⋅10 °C , where R is the resistance at t = 100 °C and

100
R is the resistance at t = 0 °C.

This document covers platinum resistors and thermometers for the temperature range −200 °C

to +850 °C with different tolerance classes. It can also cover particular platinum resistors or

thermometers for a part of this temperature range.

For resistance versus temperature relationships with uncertainties less than 0,1 °C, which are

possible only for platinum resistors or thermometers with exceptionally high stability and

individual calibration, a more complex interpolation equation than is presented in this document

can be necessary. The specification of such equations is outside the scope of this document.

2 Normative references

The following documents are referred to in the text in such a way that some or all of their content

constitutes requirements of this document. For dated references, only the edition cited applies.

For undated references, the latest edition of the referenced document (including any

amendments) applies.

IEC 60068-2-6, Environmental testing – Part 2-6: Tests – Test Fc: Vibration (sinusoidal)

IEC 61152, Dimensions of metal-sheathed thermometer elements

IEC 61515:2016, Mineral insulated metal-sheathed thermocouple cables and thermocouples

---------------------- Page: 12 ----------------------
SIST EN IEC 60751:2022
IEC 60751:2022 © IEC 2022 – 7 –
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.

ISO and IEC maintain terminological databases for use in standardization at the following

addresses:
• IEC Electropedia: available at https://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp
3.1
platinum resistor

resistor made from a platinum wire or film with defined electrical characteristics, embedded in

an insulator (in most cases glass or ceramic), designed to be assembled into a platinum

resistance thermometer or into an integrated circuit
3.2
platinum resistance thermometer
thermometer
PRT

temperature-responsive device consisting of one or more sensing platinum resistors within a

protective sheath, internal connecting wires, and external terminals to permit connection of

electrical measurement instruments

Note 1 to entry: Mounting means and connection heads can be included. Not included is any separable protection

tube or thermowell.
3.3
nominal resistance

expected resistance R of a platinum resistor or thermometer at 0 °C, declared by the supplier

and shown in the thermometer marking, usually rounded to the nearest ohm

Note 1 to entry: Platinum resistors are often characterized by their nominal resistance. For example, a platinum

resistor with R = 100 Ω is often referred to as a Pt100
3.4
terminals
termination of the connections supplied with the platinum resistance thermometer
Note 1 to entry: Typical types of terminals are:
• screws or clamps on the terminal socket,
• pins of fixed connectors,
• open ends of fixed cables or equivalents.
3.5
temperature-sensitive length

length of the thermometer whose temperature directly influences the resistance measured

Note 1 to entry: Usually, the temperature-sensitive length is related to the length of the platinum resistor.

3.6
minimum immersion depth

immersion depth at which the change from the calibration at full immersion does not exceed

0,1 °C
3.7
tolerance

maximum allowable deviation of R(t) measured at temperature t from the nominal resistance

versus temperature relationship expressed as Δt(t) in °C
---------------------- Page: 13 ----------------------
SIST EN IEC 60751:2022
– 8 – IEC 60751:2022 © IEC 2022
3.8
dielectric strength

maximum voltage between all parts of the electric circuit and the sheath of the thermometer or,

in the case of a thermometer with two or more sensing circuits, between two individual circuits

that the thermometer can withstand without damage
3.9
insulation resistance

electrical resistance measured between any part of the electric circuit and the sheath at ambient

or elevated temperatures and with a specified measuring voltage (AC or DC)
3.10
self-heating

increase of the temperature of the platinum resistor or of the platinum resistor in a thermometer

caused by the dissipated energy of the measuring current
3.11
self-heating coefficient

temperature rise due to dissipated energy by measuring current in a resistor expressed with the

unit °C/mW
3.12
thermal response time

time a thermometer takes to reach a specified percentage of a step change in temperature

3.13
thermoelectric effect

effect of inducing electro-motive force (abbreviated by e.m.f hereafter) caused by different

metals used in the electric circuit of the thermometer and by thermoelectric inhomogeneity of

the internal leads at the conditions of temperature gradients along the leads
3.14
hysteresis

resistance difference at the middle of the temperature range between before and after exposing

the thermometer to the lower and upper limit of the temperature range
3.15
expanded uncertainty

quantity defining an interval about the result of a measurement that can be expected to

encompass a large fraction of the distribution of values that could reasonably be attributed to

the measurand
Note 1 to entry: For reference, see 3.16.
3.16
coverage factor

numerical factor used as a multiplier of the combined standard uncertainty in order to obtain an

expanded uncertainty

Note 1 to entry: Coverage factor, k, is typically in the range 2 to 3. In this document, k = 2 is chosen, the confidence

level of which is 95 %. Refer to Bibliography [1].
4 Characteristics
4.1 General

The nominal resistance versus temperature relationship for platinum resistors and

thermometers and their tolerance class are standardized. This specification is applied to a

sensing platinum resistor at its connecting points and to a complete thermometer at its terminals.

---------------------- Page: 14 ----------------------
SIST EN IEC 60751:2022
IEC 60751:2022 © IEC 2022 – 9 –

In the case of two-wire connections (see 5.5), the resistance values of the leads between the

connecting point of the platinum resistor and the terminals shall be considered. They shall be

subtracted from measured resistances. In some cases, it is also advisable to consider the

temperature coefficient of the lead wires, the geometrical characteristics of the wires, and the

temperature distribution along their length. This information may be supplied to users as

additional information (refer to Clause 7).
4.2 Nominal resistance versus temperature relationship

The resistance versus temperature relationships used in this document are as follows:

For the range −200 °C to 0 °C:
2 3
R = R [1 + At + Bt + C(t − 100 °C) t ]
t 0
For the range of 0 °C to 850 °C:
R = R (1 + At + Bt )
t 0
where
R is the resistance at the temperature t,
R is the resistance at t = 0 °C.
The constants in these equations are,
−3 −1
A = 3,908 3 × 10 °C
−7 −2
B = −5,775 × 10 °C
−12 −4
C = −4,183 × 10 °C .
4.3 Numerical table of resistance values

Table A.1 and Table A.2 are derived from the equations and coefficients specified in 4.2 for a

thermometer or platinum resistor of nominal resistance R of 100 Ω.

Table A.1 and Table A.2 are applicable to any thermometer and platinum resistor having any

value of R .

In this case, the resistance values in Table A.1 and Table A.2 shall be multiplied by the factor

R / 100 Ω.

NOTE 1 In this edition, the numerical tables given in Annex A cease to be normative; they are now informative. The

specification of this document is the formula described in 4.2 with which user can calculate numerical value of R .

NOTE 2 The most frequently used device has R of 100 Ω. Devices with R of 10 Ω, 500 Ω or 1000 Ω are used

0 0
frequently as well.
5 Compliance and requirements
5.1 Compliance

In order for a thermometer to be compliant with this document, it shall be made from a platinum

resistor which is compliant with this document.
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SIST EN IEC 60751:2022
– 10 – IEC 60751:2022 © IEC 2022

Platinum resistors and thermometers shall be tested to prove that the device meets all the

applicable requirements specified in this document. Suppliers shall be responsible for

conducting the tests and for proving that the device conforms to this document before

transferring the device to the user. The test method and evaluation are specified in this

document.
5.2 Tolerance
...

SLOVENSKI STANDARD
oSIST prEN IEC 60751:2021
01-marec-2021
Industrijski uporovni termometri in temperaturni senzorji iz platine
Industrial platinum resistance thermometers and platinum temperature sensors
Industrielle Platin-Widerstandsthermometer und Platin-Temperatursensoren

Thermomètres à résistance de platine industriels et capteurs thermométriques en platine

Ta slovenski standard je istoveten z: prEN IEC 60751:2020
ICS:
17.200.20 Instrumenti za merjenje Temperature-measuring
temperature instruments
oSIST prEN IEC 60751:2021 en,fr,de

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

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oSIST prEN IEC 60751:2021
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oSIST prEN IEC 60751:2021
65B/1187/CDV
COMMITTEE DRAFT FOR VOTE (CDV)
PROJECT NUMBER:
IEC 60751 ED3
DATE OF CIRCULATION: CLOSING DATE FOR VOTING:
2020-12-25 2021-03-19
SUPERSEDES DOCUMENTS:
65B/1163/CD, 65B/1184/CC
IEC SC 65B : MEASUREMENT AND CONTROL DEVICES
SECRETARIAT: SECRETARY:
United States of America Mr Angus Low
OF INTEREST TO THE FOLLOWING COMMITTEES: PROPOSED HORIZONTAL STANDARD:
Other TC/SCs are requested to indicate their interest, if
any, in this CDV to the secretary.
FUNCTIONS CONCERNED:
EMC ENVIRONMENT QUALITY ASSURANCE SAFETY

SUBMITTED FOR CENELEC PARALLEL VOTING NOT SUBMITTED FOR CENELEC PARALLEL VOTING

Attention IEC-CENELEC parallel voting
The attention of IEC National Committees, members of
CENELEC, is drawn to the fact that this Committee Draft for
Vote (CDV) is submitted for parallel voting.
The CENELEC members are invited to vote through the
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This document is still under study and subject to change. It should not be used for reference purposes.

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they are aware and to provide supporting documentation.
TITLE:
Industrial platinum resistance thermometers and platinum temperature sensors
PROPOSED STABILITY DATE: 2025
NOTE FROM TC/SC OFFICERS:

Copyright © 2020 International Electrotechnical Commission, IEC. All rights reserved. It is permitted to download this

electronic file, to make a copy and to print out the content for the sole purpose of preparing National Committee positions.

You may not copy or "mirror" the file or printed version of the document, or any part of it, for any other purpose without

permission in writing from IEC.
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65B/1187/CDV IEC CDV 60751/Ed3 © IEC 2020
1 CONTENTS

2 1 Scope ............................................................................................................................. 5

3 2 Normative references ...................................................................................................... 5

4 3 Terms and Definitions ..................................................................................................... 5

5 4 Characteristics ................................................................................................................ 7

6 4.1 General .................................................................................................................. 7

7 4.2 Nominal resistance versus temperature relationship ............................................... 8

8 4.3 Numerical table of resistance values ...................................................................... 8

9 5 Compliance and requirements ......................................................................................... 8

10 5.1 Compliance ............................................................................................................ 8

11 5.2 Tolerance classes .................................................................................................. 8

12 5.2.1 Tolerance class and its temperature range of validity ...................................... 8

13 5.2.2 Tolerance class of platinum resistors .............................................................. 9

14 5.2.3 Tolerance classes and marking of platinum resistance thermometers .............. 9

15 5.3 Measuring current ................................................................................................ 10

16 5.4 Electrical supply ................................................................................................... 10

17 5.5 Connecting wire configuration............................................................................... 10

18 6 Tests ............................................................................................................................. 11

19 6.1 General ................................................................................................................ 11

20 6.1.1 Test categories ............................................................................................. 11

21 6.1.2 Routine production tests................................................................................ 11

22 6.1.3 Type tests ..................................................................................................... 11

23 6.1.4 Additional type tests for thermometers .......................................................... 11

24 6.1.5 Summary of the tests .................................................................................... 11

25 6.2 Routine production tests for platinum resistors ..................................................... 12

26 6.2.1 Tolerance acceptance test ............................................................................ 12

27 6.3 Routine production tests for thermometers ........................................................... 13

28 6.3.1 Tolerance acceptance test ............................................................................ 13

29 6.3.2 Insulation resistance at ambient temperature ................................................ 13

30 6.3.3 Sheath integrity test ...................................................................................... 13

31 6.3.4 Dimensional test ........................................................................................... 14

32 6.4 Type tests for platinum resistors ........................................................................... 14

33 6.4.1 Tolerances .................................................................................................... 14

34 6.4.2 Stability at upper temperature limit ................................................................ 14

35 6.4.3 Self-heating................................................................................................... 14

36 6.5 Type tests for thermometers ................................................................................. 14

37 6.5.1 Tolerances .................................................................................................... 14

38 6.5.2 Stability at upper temperature limit ................................................................ 14

39 6.5.3 Self-heating................................................................................................... 15

40 6.5.4 Insulation resistance at elevated temperature ............................................... 15

41 6.5.5 Thermal response time .................................................................................. 15

42 6.5.6 Thermoelectric effect ..................................................................................... 15

43 6.5.7 Effect of temperature cycling ......................................................................... 15

44 6.5.8 Effect of hysteresis........................................................................................ 15

45 6.5.9 Minimum immersion depth ............................................................................. 16

46 6.6 Additional type tests for thermometers .................................................................. 16

47 6.6.1 General ......................................................................................................... 16

48 6.6.2 Capacitance .................................................................................................. 16

49 6.6.3 Inductance .................................................................................................... 16

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50 6.6.4 Dielectric strength ......................................................................................... 16

51 6.6.5 Vibration test ................................................................................................. 16

52 6.6.6 Drop test ....................................................................................................... 16

53 6.6.7 Cold seal ....................................................................................................... 16

54 7 Information to be made available by the supplier ........................................................... 16

55 7.1 For Leads of platinum resistors (platinum resistors only) ...................................... 16

56 7.2 For platinum resistors and/or thermometers .......................................................... 17

57 Annex A (informative) Numerical Table ................................................................................ 18

59 Figure 1 – Example of connecting configurations .................................................................. 11

60 Figure 2 – Examples of test results for selecting or rejecting platinum resistors are shown in

61 case of the tolerance class 0,1. The limits are part of the tolerance band. ............................ 13

63 Table 1 – Tolerance class of platinum resistors ...................................................................... 9

64 Table 2 – Tolerance class of thermometers ............................................................................ 9

65 Table 3 – Table of tests specified in this standard ................................................................ 12

66 Table 4 – Minimum insulation resistance of thermometers at maximum temperature ............ 15

67 Table A.1 – Temperature versus resistance relationship; R = 100,00 Ω ............................. 18

71 Foreword
72 1)

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

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

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

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

82 agreement between the two organizations.
84 2)

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

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

87 interested IEC National Committees.
89 3)

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

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

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

93 misinterpretation by any end user.
95 4)

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

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

99 the latter.
100
101 5)

102 IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any

103 equipment declared to be in conformity with an IEC Publication.
104
105 6)

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

107
108 7)

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

110 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

111

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

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113 Publications.
114
115 8)

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

117 indispensable for the correct application of this publication.
118
119 9)

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

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

122

123 International Standard IEC 60751 has been prepared by subcommittee 65B: Devices and

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

125 automation.
126

127 This third edition cancels and replaces the second edition published in 2008, amendment 1

128 (1986) and amendment 2 (1995). This edition constitutes a technical revision.

129

130 The significant technical changes with respect to the previous edition are as follows:

131

132 While the temperature versus resistance relationship remains unchanged, there are several

133 changes in the other chapters. Most important are:
134

135 – formula of resistance versus temperature relationship become the standard specification and nu-

136 merical table ceases to be the standard
137 – tolerance acceptance test is slightly modified;
138 – several changes in the individual tests;

139 – numerical table of resistance versus temperature is included in the annex as a reference .

140
141 The text of this standard is based on the following documents:
142
143 Enquiry draft Report on voting
144 65B/XXX/CDV 65B/XXX
145

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

147 voting indicated in the above table.
148

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

150

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

152 the maintenance result date1 indicated on the IEC web site under "http://webstore.iec.ch" in

153 the data related to the specific publication. At this date, the publication will be

154
155 • reconfirmed,
156 • withdrawn,
157 • replaced by a revised edition or amended.
158
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159 Industrial platinum resistance
160 thermometers and platinum temperature
161 sensors
162
163 1 Scope

164 This standard specifies the requirements and resistance versus temperature relationship for indus-

165 trial platinum resistance thermometers later referred to as "thermometers" and industrial platinum

166 resistance temperature sensors later referred to as “platinum resistors” whose electrical resistance

167 is derived by defined function of temperature.

168 The standard applies to platinum resistors whose temperature coefficient α, defined as

R −R
100 0
169 ,
α =
R ⋅100°C
-3 -1

170 is conventionally written as α = 3,851⋅10 °C , where R is the resistance at t = 100 °C and R is

100 0
171 the resistance at t = 0 °C.
172

173 Values of temperature in this standard are in terms of the International Temperature Scale of 1990,

174 ITS-90. Temperatures in degrees Celsius are denoted by the symbol t, except in Table A.1 where

175 the full nomenclature t90/°C is used.

176 The standard covers platinum resistors or thermometers for all or part of the temperature

177 range -200 °C to +850 °C with different tolerance classes, which may cover restricted temperature

178 ranges.
179

180 For temperature/resistance relationships with uncertainties less than 0,1 °C, which are possible only

181 for platinum resistors or thermometers with exceptionally high stability and individual calibration, a

182 more complex interpolation equation than is presented in this standard may be necessary. The

183 specification of such equations is outside the scope of this standard.
184

185 In order for a thermometer to be compliant with this standard it shall be made from a platinum resis-

186 tor which is compliant with this standard.
187
188 2 Normative references

189 The following normative document contains provisions which, through reference to this text, consti-

190 tute provisions of this International Standard:
191

192 IEC 61515 : Process Measurement and Control devices –Mineral insulated metal sheathed thermo-

193 couple cables and thermocouples

194 IEC 61298-1: Process Measurement and Control devices – General Methods and Procedures for

195 Evaluating Performance – Part 1: General considerations

196 IEC 60068-2-6: Environmental testing - Part 2-6: Tests - Test Fc: Vibration (sinusoidal)

197
198 IEC 61152: Dimensions of metal sheathed thermometer elements
199

200 JCGM 100:2008 Evaluation of measurement data — Guide to the expression of uncertainty in

201 measurement (GUM).
202 3 Terms and Definitions
203
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204 3.1
205 platinum resistor

206 resistor made from a platinum wire or film with defined electrical characteristics, embedded in an

207 insulator (in most cases glass or ceramic), designed to be assembled into a platinum resistance

208 thermometer or into an integrated circuit
209
210 3.2
211 platinum resistance thermometer
212 PRT

213 temperature responsive device consisting of one or more sensing platinum resistors within a protec-

214 tive sheath, internal connecting wires and external terminals to permit connection of electrical

215 measurement instruments

216 Note 1 to entry; Mounting means and connection heads may be included. Not included is any separable protection tube or

217 thermo-well
218
219 3.3
220 nominal resistance

221 expected resistance R of a platinum resistor or resistance thermometer at 0 °C, declared by the

222 supplier and shown in the thermometer marking, usually rounded to the nearest ohm

223 Note 1 to entry; platinum resistors are often characterized by their nominal values. For example platinum resistor of Pt-

224 100 is a platinum resistor with R = 100 Ω.
225
226 3.4
227 terminals

228 termination of the connections supplied with the platinum resistance thermometer

229 Note1 to entry: Typical types of terminals are:
230 • screws or clamps on the terminal socket
231 • pins of fixed connectors
232 • open ends of fixed cables or equivalents.
233
234 3.5
235 temperature sensitive length

236 length of the thermometer whose temperature directly influences the resistance measured

237 Note1 to entry; usually the temperature sensitive length is related to the length of the platinum resistor.

238
239 3.6
240 minimum immersion depth

241 immersion depth at which the change from the calibration at full immersion does not exceed 0,1 °C

242
243 3.7
244 tolerance

245 maximum allowable deviation of R(t) measured at temperature t from the nominal resistance versus

246 temperature relationship expressed as ∆t(t) in degrees Celsius
247
248 3.8
249 dielectric strength

250 maximum voltage between all parts of the electric circuit and the sheath of the thermometer and in

251 the case of a thermometer with two or more sensing circuits, between two individual circuits which

252 the thermometer can withstand without damage
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253
254 3.9
255 insulation resistance

256 electrical resistance measured between any part of the electric circuit and the sheath at ambient or

257 elevated temperatures and with a specified measuring voltage (AC or DC)
258
259 3.10
260 self-heating

261 increase of the temperature of the platinum resistor or of the platinum resistor in a thermometer

262 caused by the dissipated energy of the measuring current
263
264 3.11
265 self-heating coefficient

266 coefficient with the unit °C/mW is a characteristic for a platinum resistor or a thermometer and de-

267 scribes the temperature increase of the platinum resistor per unit power dissipated under specified

268 operating conditions of the platinum resistor or thermometer
269
270 3.12
271 thermal response time

272 time a thermometer takes to respond at a specified percentage to a step change in temperature

273
274 3.13
275 thermoelectric effect

276 effect of inducing electro-motive force (abbreviated by emf hereafter) caused by different metals

277 used in the electric circuit of the thermometer and by thermoelectric inhomogeneity of the internal

278 leads at the conditions of temperature gradients along the leads
279 3.14
280 hysteresis

281 difference between resistance measured in the middle of the temperature range after exposure the

282 thermometer to the lower limit and to the upper limit of the temperature range

283
284 3.15
285 expanded uncertainty

286 quantity defining an interval about the result of a measurement that may be expected to encompass

287 a large fraction of the distribution of values that could reasonably be attributed to the measurand

288 Note1 to entry: for reference see 3.16.
289
290 3.16
291 coverage factor

292 numerical factor used as a multiplier of the combined standard uncertainty in order to obtain an ex-

293 panded uncertainty
294 Note1 to entry: Coverage factor, k, is typically in the range 2 to 3.

295 [SOURCE: JCGM 100:2008, GUM 1995 with minor corrections. BIPM (Bureau International des

296 Poids et Mesures), published on-line at www.bipm.org.]
297 4 Characteristics
298 4.1 General

299 The nominal resistance versus temperature relationship for platinum resistors and thermometers

300 and their tolerance class are standardized. This specification is applied to a sensing platinum resis-

301 tor at its connecting points and to a complete thermometer at its terminals.
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302 In the case of two-wire connections (see 5.5) the resistance values of the leads between the con-

303 necting point of the platinum resistor and the terminals must be considered. They must be subtract-

304 ed from measured resistances. In some cases it also may be advisable to consider the temperature

305 coefficient of the lead wires, the geometrical characteristics of the wires and the temperature distri-

306 bution along their length. These information may be supplied to users as additional information (re-

307 fer to 7).
308
309 4.2 Nominal resistance versus temperature relationship

310 The resistance versus temperature relationships used in this standard are as follows:

311
312 For the range -200 °C to 0 °C:
2 3
313 R = R [1 + At + Bt + C(t - 100 °C) t ]
t 0
314
315 For the range of 0 °C to 850 °C:
316 R = R (1 + At + Bt )
t 0
317 where
318 R is the resistance at the temperature t
319 R0 is the resistance at t = 0 °C.
320
321 The constants in these equations are
322
-3 -1
323 A = 3,9083 x 10 °C
-7 -2
324 B = -5,775 x 10 °C
-12 -4
325 C = -4,183 x10 °C .
326
327 4.3 Numerical table of resistance values

328 Table A.1 is derived by applying the equations and coefficients specified in 4.2 to a thermometer or

329 platinum resistor of nominal resistance R of 100 Ω.

330 The table is applicable to any thermometer and platinum resistor having any value of R0 .

331 In this case resistance values in the Table A.1 shall be multiplied by the factor R /100 Ω.

332 Note 1 to entry; in this edition numerical table ceased to be the standard but becomes information. The specification of the

333 standard is the formula described in 4.2 with which user can calculate numerical value of R .

334 Note 2 to the entry; most frequently used device has R of 100 Ω. Devices with R of 10 Ω, 500Ω or 1000 Ω are used fre-

0 0
335 quently as well.
336 5 Compliance and requirements
337 5.1 Compliance

338 Platinum resistors and platinum resistance thermometers shall be tested to prove that the device

339 meets all the applicable requirements specified in this standard. Suppliers shall be responsible to

340 conducting the tests and to proving that the device is compliant with this standard before transfer-

341 ring the device to the user. The test method and evaluation are specified in this standard.

342 5.2 Tolerance classes
343 5.2.1 Tolerance class and its temperature range of validity

344 Tolerance classes for a platinum resistor are given in the Table 1 and for a platinum resistance

345 thermometer in the Table 2 for any value of R .

346 These tolerance classes are closely related to the operable temperature range. Therefore the tem-

347 perature ranges of validity of a tolerance class are shown in the adjacent column in the table. Tem-

348 perature ranges of validity are based on the working experience with film and wire platinum resis-

349 tors.

350 A thermometer that has wider temperature range of validity than the Table 2 can be compliant with

351 this standard provided that it meets all the applicable specifications and its temperature range is

352 declared.
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353 Likewise a thermometer or a platinum resistor that has a restricted temperature range of validity

354 compared to the Table 1 or Table 2 can be compliant with this standard provide that it meets all the

355 other applicable specifications and its temperature range is declared.

356 Thermometers or platinum resistors without a temperature range of validity of tolerance are not

357 permitted in this standard.
358
359 5.2.2 Tolerance class of platinum resistors

360 Table 1 specifies tolerance class of platinum resistors. Tolerances and ranges of validity which

361 differ from values given in Table 1 shall be agreed between supplier and user.

362 Table 1 – Tolerance class of platinum resistors
363
Wire wound platinum resistors Film platinum resistors
Temperature Temperature
Tolerance Tolerance
range of validity range of validity Tolerance (°C)
class class
(°C) (°C)
W 0,1 -100 to +350 F 0,1 0 to +150 ±( 0,1 + 0,0017 | t | )
-100 to +450 -30 to +300
W 0,15 F 0,15 ±( 0,15 + 0,002 | t | )
W 0,3 -196 to +660 F 0,3 -50 to +500
±( 0,3 + 0,005 | t | )
W 0,6 -196 to +660 F 0,6 -50 to +600 ±( 0,6 + 0,01 | t | )

Note The symbol | t | denotes modulus of temperature in t °C without regard to sign.

364
365 5.2.3 Tolerance classes and marking of platinum resistance thermometers
366 5.2.3.1 Tolerance classes of platinum resistance thermometers
367 Table 2 specifies tolerance class of platinum resistance thermometers.
368 Table 2 – Tolerance class of thermometers
369
Temperature range of validity (°C) for
thermometers made using Tolerance
Tolerance class
Wire wound platinum Film platinum resistors (°C)
resistors
0 to +150
AA -50 to +250 ±( 0,1 + 0,0017 | t |)
-30 to +300
A -100 to +450 ±( 0,15 + 0,002 | t | )
-50 to +500
B -196 to +600
±( 0,3 + 0,005 | t | )
-50 to +600
C -196 to +600 ±( 0,6 + 0,01 | t | )

Note The symbol | t | denotes modulus of temperature in t °C without regard to sign.

370
371 5.2.3.2 Special tolerance classes of platinum resistance thermometers

372 Tolerances and ranges of validity which differ from the values given in Table 2 shall be agreed be-

373 tween supplier and user. Recommended special tolerance classes may be constructed as multiples

374 or fractions of class B tolerance. The Example 1 shown in 5.2.3.3 demonstrates this case.

375 It is also left to the suppliers and users to establish tolerance class for their thermometers at tem-

376 peratures outside the ranges in Table 2. Special tolerance classes may be defined for restricted or

377 extended temperature ranges. The Example 2 shown in 5.2.3.3 demonstrates this case.

378 Platinum resistance thermometers without specification of the temperature range of validity are not

379 permissible.
380
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381 5.2.
...

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