IEC 62631-3-2:2023

Dielectric and resistive properties of solid insulating materials - Part 3-2: Determination of resistive properties (DC methods) - Surface resistance and surface resistivity

IEC 62631-3-2:2023 describes methods of test for the determination of surface resistance and surface resistivity of electrical insulation materials by applying DC voltage. This edition includes the following significant technical changes with respect to the previous edition:
a) descriptions of the electrode arrangements have been clarified;
b) new descriptions of the conductive means have been added;
c) a new informative Annex B summarizing the results of the comparative verification study on surface resistivities using different electrode arrangements has been added.

Propriétés diélectriques et résistives des matériaux isolants solides - Partie 3-2: Détermination des propriétés résistives (méthodes en courant continu) - Résistance superficielle et résistivité superficielle

L'IEC 62631-3-2:2023 décrit les méthodes d'essai pour déterminer la résistance superficielle et la résistivité superficielle de matériaux isolants électriques par application d'une tension continue. Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
a) les descriptions relatives aux montages d'électrodes ont été clarifiées;
b) de nouvelles descriptions ont été ajoutées pour les matériaux conducteurs;
c) une nouvelle Annexe B informative a été ajoutée; elle récapitule les résultats de l'étude de vérification comparative sur les résistivités superficielles effectuée avec différents montages d'électrodes.

General Information

• Status: Published
• Publication Date: 15-Oct-2023
• ICS: 17.220.99 - Other standards related to electricity and magnetism
• ICS: 29.035.01 - Insulating materials in general
• Technical Committee: TC 112 - Evaluation and qualification of electrical insulating materials and systems
• Drafting Committee: WG 4 - TC 112/WG 4
• Current Stage: PPUB - Publication issued
• Start Date: 20-Oct-2023
• Completion Date: 16-Oct-2023

Relations

• Revises: IEC 62631-3-2:2015 - Dielectric and resistive properties of solid insulating materials - Part 3-2: Determination of resistive properties (DC methods) - Surface resistance and surface resistivity
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC 62631-3-2 ®
Edition 2.0 2023-10
COMMENTED VERSION
INTERNATIONAL
STANDARD
colour
inside
Dielectric and resistive properties of solid insulating materials –
Part 3-2: Determination of resistive properties (DC methods) – Surface
resistance and surface resistivity
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.

IEC Secretariat Tel.: [phone]
3, rue de Varembé [e-mail]
CH-1211 Geneva 20 www.iec.ch
Switzerland
About the IEC
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International Standards for all electrical, electronic and related technologies.

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IEC 62631-3-2 ®
Edition 2.0 2023-10
COMMENTED VERSION
INTERNATIONAL
STANDARD
colour
inside
Dielectric and resistive properties of solid insulating materials –
Part 3-2: Determination of resistive properties (DC methods) – Surface
resistance and surface resistivity
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 17.220.99, 29.035.01   ISBN 978-2-8322-7699-0

– 2 – IEC 62631-3-2:2023 CMV © IEC 2023
CONTENTS
FOREWORD .4
1 Scope .6
2 Normative references .6
3 Terms and definitions .6
4 Significance .8
5 Method of test .9
5.1 General .9
5.2 Voltage .9
5.3 Equipment .9
5.3.1 General .9
5.3.2 Accuracy . 10
5.3.3 Voltage source . 10
5.3.4 Electrode arrangements . 10
5.4 Test circuit . 15
5.5 Calibration . 16
5.6 Test specimen . 16
5.6.1 Recommended dimensions of test specimen and electrode
arrangements . 16
5.6.2 Manufacturing of test specimen . 16
5.6.3 Number of test specimens . 17
5.6.4 Application of electrodes conductive means . 17
5.6.5 Conditioning and pre-treatment of test specimen . 17
5.7 Test procedure . 18
6 Evaluation Calculation of surface resistivity . 18
6.1 For electrode arrangements A, B, D and E. 18
6.2 For electrode arrangement C . 18
7 Test report . 19
8 Repeatability and reproducibility . 19
Annex A (informative) Specimen dimensions and electrode arrangements . 20
Annex B (informative) Comparative verification study on surface resistivities using
different electrode arrangements (type C and type E) . 21
B.1 General . 21
B.2 Inter-laboratory trial conditions . 21
B.2.1 General . 21
B.2.2 Test specimens . 21
B.2.3 Electrode types, conductive materials and test voltage . 21
B.2.4 Test conditions . 22
B.3 Summary of the test results . 22
B.4 Inter-laboratory trial outcomes and suggestions for IEC 62631-3-2 . 23
B.5 Detailed inter-laboratory results . 23
B.5.1 General . 23
B.5.2 Laboratories results by different groups of electrode types and
conductive materials for the different test specimens . 24
B.5.3 Laboratory 2 results comparing different electrode types and conductive
materials . 30
B.5.4 Laboratory 3 results – Electrode type C with and without use of
conductive silver paint . 32

Bibliography . 34
List of comments . 35

Figure 1 – Electrode arrangement A (example) . 11
Figure 2 – Collector electrode for electrode arrangement B Electrode arrangement B
(example) . 12
Figure 3 – Electrode arrangement C (example) . 13
Figure 4 – Connection diagram of measurement with two- and three-terminal electrode
arrangements . 16
Figure B.1 – Surface resistivity equations for the used electrodes . 22

Table 1 – Typical electrode dimensions for electrode arrangement C . 14
Table A.1 – Recommended test specimen dimensions and electrode arrangements for
specific products . 20
Table B.1 – Test specimens characteristics . 21
Table B.2 – Test conditions per specific participant . 22
Table B.3 – Summary of the test results . 23
Table B.4 – Polybutylene terephthalate (PBT) test specimen results – Electrode type C
with conductive rubber . 24
Table B.5 – Polyamide 66 (PA66) test specimen results – Electrode type C with
conductive rubber . 25
Table B.6 – Polybutylene terephthalate (PBT) test specimen results – Electrode type C
with conductive silver paint . 26
Table B.7 – Polyamide 66 (PA66) test specimen results – Electrode type C with
conductive silver paint . 27
Table B.8 – Polybutylene terephthalate (PBT results) test specimen results – Electrode
type E with conductive silver paint . 28
Table B.9 – Polyamide 66 (PA66) test specimen results – Electrode type E with
conductive silver paint . 29
Table B.10 – Laboratory 2 results – Polybutylene terephthalate (PBT) – Different
electrodes and conductive materials . 30
Table B.11 – Laboratory 2 results – Polyamide 66 (PA66) – Different electrodes and
conductive materials . 31
Table B.12 – Laboratory 3 results – Polybutylene terephthalate (PBT) – Electrode type
C with and without conductive silver paint . 32
Table B.13 – Laboratory 3 results – Polyamide 66 (PA66) – Electrode type C with and
without conductive silver paint . 33

– 4 – IEC 62631-3-2:2023 CMV © IEC 2023
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
DIELECTRIC AND RESISTIVE PROPERTIES
OF SOLID INSULATING MATERIALS –

Part 3-2: Determination of resistive properties (DC methods) –
Surface resistance and surface resistivity

FOREWORD
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IEC 62631-3-2 ®
Edition 2.0 2023-10
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Dielectric and resistive properties of solid insulating materials –
Part 3-2: Determination of resistive properties (DC methods) – Surface
resistance and surface resistivity
Propriétés diélectriques et résistives des matériaux isolants solides –
Partie 3-2: Détermination des propriétés résistives (méthodes en courant
continu) – Résistance superficielle et résistivité superficielle
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
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About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.
About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigendum or an amendment might have been published.
IEC publications search - webstore.iec.ch/advsearchform IEC Products & Services Portal - products.iec.ch
The advanced search enables to find IEC publications by a Discover our powerful search engine and read freely all the
variety of criteria (reference number, text, technical publications previews. With a subscription you will always have
committee, …). It also gives information on projects, replaced access to up to date content tailored to your needs.
and withdrawn publications.
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The world's leading online dictionary on electrotechnology,
Stay up to date on all new IEC publications. Just Published
containing more than 22 300 terminological entries in English
details all new publications released. Available online and once
and French, with equivalent terms in 19 additional languages.
a month by email.
Also known as the International Electrotechnical Vocabulary
(IEV) online.
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If you wish to give us your feedback on this publication or need
further assistance, please contact the Customer Service
Centre: [e-mail].
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IEC 62631-3-2 ®
Edition 2.0 2023-10
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Dielectric and resistive properties of solid insulating materials –
Part 3-2: Determination of resistive properties (DC methods) – Surface
resistance and surface resistivity
Propriétés diélectriques et résistives des matériaux isolants solides –
Partie 3-2: Détermination des propriétés résistives (méthodes en courant
continu) – Résistance superficielle et résistivité superficielle
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 17.220.99, 29.035.01 ISBN 978-2-8322-7549-8
– 2 – IEC 62631-3-2:2023 © IEC 2023
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Significance . 8
5 Method of test . 8
5.1 General . 8
5.2 Voltage . 9
5.3 Equipment . 9
5.3.1 General . 9
5.3.2 Accuracy . 9
5.3.3 Voltage source . 10
5.3.4 Electrode arrangements . 10
5.4 Test circuit . 14
5.5 Calibration . 15
5.6 Test specimen . 15
5.6.1 Recommended dimensions of test specimen and electrode
arrangements . 15
5.6.2 Manufacturing of test specimen . 15
5.6.3 Number of test specimens . 16
5.6.4 Application of conductive means . 16
5.6.5 Conditioning and pre-treatment of test specimen . 16
5.7 Test procedure . 17
6 Calculation of surface resistivity . 17
6.1 For electrode arrangements A, B, D and E . 17
6.2 For electrode arrangement C . 17
7 Test report . 18
8 Repeatability and reproducibility . 18
Annex A (informative) Specimen dimensions and electrode arrangements . 19
Annex B (informative) Comparative verification study on surface resistivities using
different electrode arrangements (type C and type E) . 20
B.1 General . 20
B.2 Inter-laboratory trial conditions . 20
B.2.1 General . 20
B.2.2 Test specimens . 20
B.2.3 Electrode types, conductive materials and test voltage . 20
B.2.4 Test conditions . 21
B.3 Summary of the test results . 21
B.4 Inter-laboratory trial outcomes and suggestions for IEC 62631-3-2 . 22
B.5 Detailed inter-laboratory results . 22
B.5.1 General . 22
B.5.2 Laboratories results by different groups of electrode types and
conductive materials for the different test specimens . 23
B.5.3 Laboratory 2 results comparing different electrode types and conductive
materials . 29
B.5.4 Laboratory 3 results – Electrode type C with and without use of
conductive silver paint . 31

Bibliography . 33

Figure 1 – Electrode arrangement A (example) . 11
Figure 2 – Electrode arrangement B (example) . 12
Figure 3 – Electrode arrangement C (example) . 13
Figure 4 – Connection diagram of measurement with two- and three-terminal electrode
arrangements. 15
Figure B.1 – Surface resistivity equations for the used electrodes . 21

Table 1 – Typical electrode dimensions for electrode arrangement C . 13
Table A.1 – Recommended test specimen dimensions and electrode arrangements for

specific products . 19
Table B.1 – Test specimens characteristics . 20
Table B.2 – Test conditions per specific participant . 21
Table B.3 – Summary of the test results . 22
Table B.4 – Polybutylene terephthalate (PBT) test specimen results – Electrode type C
with conductive rubber . 23
Table B.5 – Polyamide 66 (PA66) test specimen results – Electrode type C with
conductive rubber . 24
Table B.6 – Polybutylene terephthalate (PBT) test specimen results – Electrode type C
with conductive silver paint . 25
Table B.7 – Polyamide 66 (PA66) test specimen results – Electrode type C with
conductive silver paint . 26
Table B.8 – Polybutylene terephthalate (PBT results) test specimen results – Electrode
type E with conductive silver paint . 27
Table B.9 – Polyamide 66 (PA66) test specimen results – Electrode type E with
conductive silver paint . 28
Table B.10 – Laboratory 2 results – Polybutylene terephthalate (PBT) – Different
electrodes and conductive materials . 29
Table B.11 – Laboratory 2 results – Polyamide 66 (PA66) – Different
...