Directly heated negative temperature coefficient thermistors - Part 2: Sectional specification - Surface mount negative temperature coefficient thermistors (IEC 60539-2:2019)

EN-IEC 60539-2 is applicable to surface mount directly heated negative temperature coefficient thermistors, typically made from transition metal oxide materials with semiconducting properties. These thermistors have metallized connecting pads or soldering strips and are intended to be mounted directly on to substrates for hybrid circuits or on to printed boards.

Direkt geheizte temperaturabhängige Widerstände mit negativem Temperaturkoeffizienten - Teil 2: Rahmenspezifikation - Oberflächenmontierbare temperaturabhängige Widerstände mit negativem Temperaturkoeffizienten (IEC 60539-2:2019)

Thermistances à coefficient de température négatif à chauffage direct - Partie 2: Spécification intermédiaire - Thermistances à coefficient de température négatif pour montage en surface (IEC 60539-2:2019)

IEC 60539-2:2019 est disponible sous forme de IEC 60539-2:2019 RLV qui contient la Norme internationale et sa version Redline, illustrant les modifications du contenu technique depuis l'édition précédente.L'IEC 60539-2:2019 s'applique aux thermistances à coefficient de température négatif à chauffage direct pour montage en surface, typiquement constituées de matériaux faits d'oxyde de métal de transition dotés de propriétés semi-conductrices. Ces thermistances sont équipées de contacts de connexion métallisés ou de bandes de brasure et sont destinées à être montées directement sur des substrats pour circuits hybrides ou sur des cartes imprimées. La présente édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente: a) révision de la structure conformément aux directives ISO/IEC, Partie 2:2016 (septième édition), dans la mesure du possible, et pour l'harmonisation avec l'IEC 60539-1:2016; b) les températures maximales de catégorie 175 °C, 200 °C, 250 °C, 315 °C, 400 °C ont été ajoutées dans le Tableau 1; c) les dimensions de 0402M à l'Annexe A ont été ajoutées.

Neposredno ogrevani termistorji z negativnim temperaturnim koeficientom - 2. del: Področna specifikacija - Termistorji z negativnim temperaturnim koeficientom za površinsko montažo (IEC 60539-2:2019)

Standard EN-IEC 60539-2 se uporablja za neposredno ogrevane termistorje z negativnim temperaturnim koeficientom za površinsko montažo, ki so običajno izdelani iz materialov prehodnega kovinskega oksida s polprevodniškimi lastnostmi. Ti termistorji imajo metalizirane priključne blazinice ali varilne trakove ter so namenjeni namestitvi neposredno na podloge za hibridne tokokroge ali na tiskana vezja.

General Information

Status
Published
Publication Date
03-Oct-2019
Technical Committee
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
01-Oct-2019
Due Date
06-Dec-2019
Completion Date
04-Oct-2019

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SLOVENSKI STANDARD
SIST EN IEC 60539-2:2019
01-december-2019
Nadomešča:
SIST EN 60539-2:2004
SIST EN 60539-2:2004/A1:2010

Neposredno ogrevani termistorji z negativnim temperaturnim koeficientom - 2. del:

Področna specifikacija - Termistorji z negativnim temperaturnim koeficientom za
površinsko montažo (IEC 60539-2:2019)
Directly heated negative temperature coefficient thermistors - Part 2: Sectional

specification - Surface mount negative temperature coefficient thermistors (IEC 60539-

2:2019)
Direkt geheizte temperaturabhängige Widerstände mit negativem
Temperaturkoeffizienten - Teil 2: Rahmenspezifikation - Oberflächenmontierbare

temperaturabhängige Widerstände mit negativem Temperaturkoeffizienten (IEC 60539-

2:2019)

Thermistances à coefficient de température négatif à chauffage direct - Partie 2:

Spécification intermédiaire - Thermistances à coefficient de température négatif pour

montage en surface (IEC 60539-2:2019)
Ta slovenski standard je istoveten z: EN IEC 60539-2:2019
ICS:
31.040.30 Termistorji Thermistors
SIST EN IEC 60539-2:2019 en

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

---------------------- Page: 1 ----------------------
SIST EN IEC 60539-2:2019
---------------------- Page: 2 ----------------------
SIST EN IEC 60539-2:2019
EUROPEAN STANDARD EN IEC 60539-2
NORME EUROPÉENNE
EUROPÄISCHE NORM
September 2019
ICS 31.040.30 Supersedes EN 60539-2:2004 and all of its amendments
and corrigenda (if any)
English Version
Directly heated negative temperature coefficient thermistors -
Part 2: Sectional specification - Surface mount negative
temperature coefficient thermistors
(IEC 60539-2:2019)

Thermistances à coefficient de température négatif à Direkt geheizte temperaturabhängige Widerstände mit

chauffage direct - Partie 2: Spécification intermédiaire - negativem Temperaturkoeffizienten - Teil 2:

Thermistances à coefficient de température négatif pour Rahmenspezifikation - Oberflächenmontierbare

montage en surface temperaturabhängige Widerstände mit negativem
(IEC 60539-2:2019) Temperaturkoeffizienten
(IEC 60539-2:2019)

This European Standard was approved by CENELEC on 2019-08-28. 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

© 2019 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.

Ref. No. EN IEC 60539-2:2019 E
---------------------- Page: 3 ----------------------
SIST EN IEC 60539-2:2019
EN IEC 60539-2:2019 (E)
European foreword

The text of document 40/2672/FDIS, future edition 2 of IEC 60539-2, prepared by IEC/TC 40

"Capacitors and resistors for electronic equipment" was submitted to the IEC-CENELEC parallel vote

and approved by CENELEC as EN IEC 60539-2:2019.
The following dates are fixed:

• latest date by which the document has to be implemented at national (dop) 2020-05-23

level by publication of an identical national standard or by endorsement

• latest date by which the national standards conflicting with the (dow) 2022-08-23

document have to be withdrawn

This document supersedes EN 60539-2:2004 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.

Endorsement notice

The text of the International Standard IEC 60539-2:2019 was approved by CENELEC as a European

Standard without any modification.
---------------------- Page: 4 ----------------------
SIST EN IEC 60539-2:2019
EN IEC 60539-2:2019 (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 60068-2-2 2007 Environmental testing - Part 2-2: Tests - EN 60068-2-2 2007
Test B: Dry heat

IEC 60068-2-14 2009 Environmental testing - Part 2-14: Tests - EN 60068-2-14 2009

Test N: Change of temperature

IEC 60068-2-58 2015 Environmental testing - Part 2-58: Tests - EN 60068-2-58 2015

Test Td: Test methods for solderability,
resistance to dissolution of metallization
and to soldering heat of surface mounting
devices (SMD)
+ A1 2017 + A1 2018
IEC 60068-2-78 - Environmental testing - Part 2-78: Tests - EN 60068-2-78 -
Test Cab: Damp heat, steady state
IEC 60539-1 2016 Directly heated negative temperature EN 60539-1 2016
coefficient thermistors - Part 1: Generic
specification
IEC 61193-2 2007 Quality assessment systems - Part 2: EN 61193-2 2007
Selection and use of sampling plans for
inspection of electronic components and
packages
---------------------- Page: 5 ----------------------
SIST EN IEC 60539-2:2019
---------------------- Page: 6 ----------------------
SIST EN IEC 60539-2:2019
IEC 60539-2
Edition 2.0 2019-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Directly heated negative temperature coefficient thermistors –
Part 2: Sectional specification – Surface mount negative temperature coefficient
thermistors
Thermistances à coefficient de température négatif à chauffage direct –
Partie 2: Spécification intermédiaire – Thermistances à coefficient de
température négatif pour montage en surface
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 31.040.30 ISBN 978-2-8322-7098-1

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 60539-2:2019
– 2 – IEC 60539-2:2019  IEC 2019
CONTENTS

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

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

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

3 Terms and definitions ...................................................................................................... 6

4 Information to be given in a detail specification ................................................................ 7

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

4.2 Outline drawing and dimensions ............................................................................. 7

4.3 Mounting ................................................................................................................. 7

4.4 Ratings and characteristics ..................................................................................... 7

4.4.1 Particular characteristics ................................................................................. 7

4.4.2 Marking ........................................................................................................... 7

5 Preferred ratings and characteristics ............................................................................... 7

5.1 Tolerances on rated zero-power resistance ............................................................. 7

5.2 Climatic categories ................................................................................................. 8

6 Quality assessment procedures ....................................................................................... 8

7 Test and measurement procedures .................................................................................. 8

7.1 Mounting ................................................................................................................. 8

7.2 Drying and recovery ................................................................................................ 8

7.2.1 Drying .............................................................................................................. 8

7.2.2 Recovery ......................................................................................................... 8

7.3 Visual examination and check of dimensions .......................................................... 8

7.3.1 Visual examination .......................................................................................... 8

7.3.2 Requirements .................................................................................................. 9

7.3.3 Marking ......................................................................................................... 10

7.3.4 Dimensions .................................................................................................... 11

7.4 Electrical tests ...................................................................................................... 11

7.4.1 Zero-power resistance ................................................................................... 11

7.4.2 B-value or resistance ratio ............................................................................. 11

7.4.3 Resistance/temperature characteristic ........................................................... 11

7.5 Thermal tests ........................................................................................................ 12

7.5.1 Dissipation factor (δ) ...................................................................................... 12

7.5.2 Thermal time constant by cooling after self-heating (τ ) ................................. 12

7.6 Resistance to soldering heat ................................................................................. 12

7.6.1 General ......................................................................................................... 12

7.6.2 Initial measurement ....................................................................................... 12

7.6.3 Test conditions .............................................................................................. 12

7.6.4 Recovery ....................................................................................................... 12

7.6.5 Final inspection, measurements and requirements......................................... 12

7.7 Solderability .......................................................................................................... 13

7.7.1 General ......................................................................................................... 13

7.7.2 Test conditions .............................................................................................. 13

7.7.3 Recovery ....................................................................................................... 13

7.7.4 Final inspection, measurements and requirements......................................... 13

7.8 Rapid change of temperature ................................................................................ 13

7.9 Thermal shock ...................................................................................................... 13

---------------------- Page: 8 ----------------------
SIST EN IEC 60539-2:2019
IEC 60539-2:2019  IEC 2019 – 3 –

7.10 Damp heat, steady state ....................................................................................... 14

7.11 Endurance ............................................................................................................ 14

7.11.1 Endurance at T and P ............................................................................. 14

3 max

7.11.2 Endurance at upper category temperature ..................................................... 15

7.12 Shear (adhesion) test ............................................................................................ 15

7.13 Substrate bending test .......................................................................................... 15

7.14 Component solvent resistance .............................................................................. 15

7.15 Solvent resistance of marking ............................................................................... 15

Annex A (normative) Guide for the specification and coding of dimensions of surface

mount negative temperature coefficient thermistors .............................................................. 16

Annex B (normative) Quality assessment procedure ............................................................ 17

B.1 Primary stage of manufacture ............................................................................... 17

B.2 Structurally similar components ............................................................................ 17

B.3 Qualification approval procedures ......................................................................... 17

B.4 Quality conformance inspection ............................................................................ 17

B.4.1 General ......................................................................................................... 17

B.4.2 Qualification approval on the basis of the fixed sample size procedure .......... 17

B.5 Quality conformance inspection ............................................................................ 19

B.5.1 Formation of inspection lots ........................................................................... 19

B.5.2 Test schedule ................................................................................................ 20

B.5.3 Delayed delivery ............................................................................................ 20

B.5.4 Assessment level ........................................................................................... 20

Figure 1 – Fault: fissure or defect ........................................................................................... 9

Figure 2 – Fault: crack ............................................................................................................ 9

Figure 3 – Separation or delamination .................................................................................... 9

Figure 4 – Exposed electrodes .............................................................................................. 10

Figure 5 – Principal faces ..................................................................................................... 10

Figure 6 – Principal terminations – Gull wing ........................................................................ 11

Figure 7 – Principal terminations – Round termination .......................................................... 11

Figure A.1 – Dimensioning of surface mount thermistors ....................................................... 16

Table 1 – Upper and lower category temperatures and duration of the damp heat test ............ 8

Table A.1 – Dimensions ........................................................................................................ 16

Table B.1 – Fixed sample size test schedule for qualification approval of surface mount

negative temperature coefficient thermistors Assessment level EZ ....................................... 19

Table B.2 – Lot-by-lot inspection ........................................................................................... 20

Table B.3 – Periodic test ....................................................................................................... 21

---------------------- Page: 9 ----------------------
SIST EN IEC 60539-2:2019
– 4 – IEC 60539-2:2019  IEC 2019
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
DIRECTLY HEATED NEGATIVE TEMPERATURE
COEFFICIENT THERMISTORS –
Part 2: Sectional specification –
Surface mount negative temperature coefficient thermistors
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 60539-2 has been prepared by IEC technical committee 40:

Capacitors and resistors for electronic equipment.

This second edition cancels and replaces the first edition published in 2003 and Amendment

1:2010. This edition constitutes a technical revision.

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

edition:

a) revision for the structure in accordance with ISO/IEC Directives, Part 2:2016 (seventh

edition) to the extent practicable, and for harmonizing with IEC 60539-1:2016;

b) the upper category temperatures of 175 °C, 200 °C, 250 °C, 315 °C, 400 °C in Table 1

have been added;
c) the dimensions of 0402M in Annex A have been added.
---------------------- Page: 10 ----------------------
SIST EN IEC 60539-2:2019
IEC 60539-2:2019  IEC 2019 – 5 –
The text of this International Standard is based on the following documents:
FDIS Report on voting
40/2672/FDIS 40/2680/RVD

Full information on the voting for the approval of this International Standard can be found in

the report on voting indicated in the above table.

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

A list of all parts in the IEC 60539 series, published under the general title Directly heated

negative temperature coefficient thermistors, can be found on the IEC website.

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

stability date indicated on the IEC website under "http://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.

IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates

that it contains colours which are considered to be useful for the correct

understanding of its contents. Users should therefore print this document using a

colour printer.
---------------------- Page: 11 ----------------------
SIST EN IEC 60539-2:2019
– 6 – IEC 60539-2:2019  IEC 2019
DIRECTLY HEATED NEGATIVE TEMPERATURE
COEFFICIENT THERMISTORS –
Part 2: Sectional specification –
Surface mount negative temperature coefficient thermistors
1 Scope

This part of IEC 60539 is applicable to surface mount directly heated negative temperature

coefficient thermistors, typically made from transition metal oxide materials with

semiconducting properties. These thermistors have metallized connecting pads or soldering

strips and are intended to be mounted directly on to substrates for hybrid circuits or on to

printed boards.
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 60068-2-2:2007, Environmental testing – Part 2-2: Tests – Tests B: Dry heat

IEC 60068-2-14:2009, Environmental testing – Part 2-14: Tests – Test N: Change of

temperature

IEC 60068-2-58:2015, Environmental testing – Part 2-58: Tests – Test Td: Test methods for

solderability, resistance to dissolution of metallization and to soldering heat of surface

mounting devices (SMD)
IEC 60068-2-58:2015/AMD1:2017

IEC 60068-2-78, Environmental testing – Part 2-78: Tests – Test Cab: Damp heat, steady

state

IEC 60539-1:2016, Directly heated negative temperature coefficient thermistors – Part 1:

Generic specification

IEC 61193-2:2007, Quality assessment systems – Part 2: Selection and use of sampling plans

for inspection of electronic components and packages
3 Terms and definitions

For the purposes of this document, the terms and definitions given in IEC 60539-1 apply.

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

addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
---------------------- Page: 12 ----------------------
SIST EN IEC 60539-2:2019
IEC 60539-2:2019  IEC 2019 – 7 –
4 Information to be given in a detail specification
4.1 General

Detail specifications shall be derived from the relevant blank detail specification.

Detail specifications shall not specify requirements inferior to those of the generic, sectional

or blank detail specification. When more severe requirements are included, they shall be

listed in 1.9 of the detail specification and indicated in the test schedules, for example, by an

asterisk.
The information given in 4.2 may for convenience, be presented in tabular form.

The information in 4.2 to 4.4 shall be given in each detail specification and the values quoted

shall preferably be selected from those given in the appropriate clause of this sectional

specification.
4.2 Outline drawing and dimensions

There shall be an illustration of the thermistor as an aid to easy recognition and for

comparison with others. Dimensions and their associated tolerances, which affect inter-

changeability and mounting, shall be given in the detail specification. All dimensions shall

preferably be stated in millimetres; however, when the original dimensions are given in inches,

the converted metric dimensions in millimetres shall be added.

Normally, the numerical values shall be given for the length, width and height of the body.

When necessary, for example when a number of items are covered by a detail specification,

the dimensions and their associated tolerances shall be placed in a table below the drawing.

When the configuration is other than described above, the detail specification shall state such

dimensional information as will adequately describe the thermistor.
4.3 Mounting

The detail specification shall give guidance on methods of mounting for normal use. Mounting

for test and measurement purposes (when required) shall be in accordance with
IEC 60539-1:2016, 5.4.
4.4 Ratings and characteristics
4.4.1 Particular characteristics

Additional characteristics may be listed when they are considered necessary to specify the

component adequately for design and application purposes.
4.4.2 Marking
See IEC 60539-1:2016, 4.3.
5 Preferred ratings and characteristics
5.1 Tolerances on rated zero-power resistance
Preferred values of tolerances on zero-power resistance are:
±0,5 %, ±1 %, ±2 %, ±3 %, ±5 %, ±10 %.
---------------------- Page: 13 ----------------------
SIST EN IEC 60539-2:2019
– 8 – IEC 60539-2:2019  IEC 2019
5.2 Climatic categories

The upper and lower category temperatures and the duration of the damp-heat steady-state

test shall be selected from Table 1.

Table 1 – Upper and lower category temperatures and duration of the damp heat test

Lower category temperature
−55, −40, −25, −10, −5, +5
Upper category temperature
70, 85, 100, 105, 125, 150, 155, 175, 200, 250, 315, 400
Damp heat, steady state
21, 42, 56
days
The detail specification shall prescribe the appropriate category.
6 Quality assessment procedures
See Annex B.
7 Test and measurement procedures
7.1 Mounting
See IEC 60539-1:2016, 5.4.
7.2 Drying and recovery
7.2.1 Drying

Where drying is called for in this specification, the thermistor shall be conditioned as follows.

For 96 h ± 4 h in an oven at a temperature of 100 °C ± 5 °C, the thermistor shall then be

allowed to cool in a desiccator using a suitable desiccant, such as activated alumina or

silicagel, and shall be kept therein from the time of removal from the oven to the beginning of

the specified tests.
7.2.2 Recovery

Unless otherwise specified, recovery shall take place under the standard atmospheric

conditions for testing (see IEC 60539-1:2016, 5.3.2).
7.3 Visual examination and check of dimensions
7.3.1 Visual examination

Visual examination shall be carried out with suitable equipment with approximately 10×

magnification and lighting appropriate to the specimen under test and the quality level

required.

The operator should have facilities available for incident or transmitted illumination as well as

an appropriate measuring facility.
---------------------- Page: 14 ----------------------
SIST EN IEC 60539-2:2019
IEC 60539-2:2019  IEC 2019 – 9 –
7.3.2 Requirements
7.3.2.1 General

Quantitative values for the requirements below may be given in the detail or in the

manufacturer’s specification.
The thermistor shall conform to the following requirements.
7.3.2.2 Requirements for ceramic
Requirements for the
...

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