ISO 2951:2019

Rubber, vulcanized rubber — Determination of insulation resistance

This document specifies a method for the determination of the insulation resistance of vulcanized and thermoplastic rubbers without discrimination between the volume and surface resistances involved. This method is applicable only to the test pieces with a resistance greater than 108 Ω. NOTE Methods of test for test pieces with a lower resistance are described in ISO 1853 and ISO 2878. Because the test pieces are simply and easily prepared, this method is particularly useful for rapidly determining values which will give a general indication of quality when great accuracy is not required.

Caoutchouc vulcanisé ou thermoplastique — Détermination de la résistance d'isolement

General Information

• Status: Published
• Publication Date: 02-Jun-2019
• ICS: 83.060 - Rubber
• Technical Committee: ISO/TC 45/SC 2 - Testing and analysis
• Drafting Committee: ISO/TC 45/SC 2/WG 1 - Physical properties
• Current Stage: 6060 - International Standard published
• Start Date: 03-Jun-2019
• Completion Date: 03-Jun-2019

RELATIONS

• Replaces: ISO 2951:2012 - Rubber, vulcanized or thermoplastic — Determination of insulation resistance
• Effective Date: 15-Dec-2017

Standards Content (sample)

INTERNATIONAL ISO
STANDARD 2951
Third edition
2019-05
Rubber, vulcanized rubber —
Determination of insulation resistance
Caoutchouc vulcanisé ou thermoplastique — Détermination de la
résistance d'isolement
Reference number
ISO 2951:2019(E)
ISO 2019
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ISO 2951:2019(E)
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© ISO 2019

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ii © ISO 2019 – All rights reserved
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ISO 2951:2019(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

Introduction ..................................................................................................................................................................................................................................v

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Terms and definitions ..................................................................................................................................................................................... 1

4 Test equipment....................................................................................................................................................................................................... 1

5 Calibration .................................................................................................................................................................................................................. 2

6 Electrodes .................................................................................................................................................................................................................... 2

6.1 General ........................................................................................................................................................................................................... 2

6.2 Conducting-paint electrodes (for flat plates, tubes and rods) ....................................................................... 2

6.3 Bar electrodes (for thin sheets and tapes) ...................................................................................................................... 2

7 Test pieces ................................................................................................................................................................................................................... 2

7.1 Test pieces for conducting-paint electrodes .................................................................................................................. 2

7.2 Test pieces for bar electrodes..................................................................................................................................................... 2

7.3 Attachment of electrodes ............................................................................................................................................................... 2

7.4 Conditioning .............................................................................................................................................................................................. 3

7.5 Number of test pieces ....................................................................................................................................................................... 3

8 Procedure..................................................................................................................................................................................................................... 3

9 Expression of results ........................................................................................................................................................................................ 3

9.1 Test pieces using conducting-paint electrodes ........................................................................................................... 3

9.2 Test pieces using bar electrodes .............................................................................................................................................. 3

10 Test report ................................................................................................................................................................................................................... 4

Annex A (informative) Cleaning and mounting of test pieces .................................................................................................... 8

Annex B (normative) Calibration schedule ................................................................................................................................................... 9

Bibliography .............................................................................................................................................................................................................................11

© ISO 2019 – All rights reserved iii
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ISO 2951:2019(E)
Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards

bodies (ISO member bodies). The work of preparing International Standards is normally carried out

through ISO technical committees. Each member body interested in a subject for which a technical

committee has been established has the right to be represented on that committee. International

organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.

ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of

electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are

described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the

different types of ISO documents should be noted. This document was drafted in accordance with the

editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/directives).

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

patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of

any patent rights identified during the development of the document will be in the Introduction and/or

on the ISO list of patent declarations received (see www .iso .org/patents).

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.

For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and

expressions related to conformity assessment, as well as information about ISO's adherence to the

World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www .iso

.org/iso/foreword .html.

This document was prepared by Technical Committee ISO/TC 45, Rubber and rubber products,

Subcommittee SC 2, Testing and analysis.

This third edition cancels and replaces the second edition (ISO 2951:2012), which has been technically

revised.
The main changes compared to the previous edition are as follows:
— The normative references have been updated in Clause 2;
— The calibration schedule has been added as Annex B.

Any feedback or questions on this document should be directed to the user’s national standards body. A

complete listing of these bodies can be found at www .iso .org/members .html.
iv © ISO 2019 – All rights reserved
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ISO 2951:2019(E)
Introduction

This document specifies an empirical method that gives a value for insulation resistance which includes,

without discrimination, both volume and surface resistance. This value can be used for the comparison

of the quality of different insulating rubbers. For general principles regarding measuring resistance,

general effects of temperature and humidity, applied voltage and time of electrification, see IEC 62631-

3-1, IEC 62631-3-2 and IEC 62631-3-3.
© ISO 2019 – All rights reserved v
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INTERNATIONAL STANDARD ISO 2951:2019(E)
Rubber, vulcanized rubber — Determination of insulation
resistance

WARNING 1 — Persons using this document should be familiar with normal laboratory practice.

This document does not purport to address all of the safety problems, if any, associated with its

use. It is the responsibility of the user to establish appropriate safety and health practices and to

determine the applicability of any other restrictions.

WARNING 2 — Certain procedures specified in this document might involve the use or generation

of substances, or the generation of waste, that could constitute a local environmental hazard.

Reference should be made to appropriate documentation on safe handling and disposal after use.

1 Scope

This document specifies a method for the determination of the insulation resistance of vulcanized and

thermoplastic rubbers without discrimination between the volume and surface resistances involved.

This method is applicable only to the test pieces with a resistance greater than 10 Ω.

NOTE Methods of test for test pieces with a lower resistance are described in ISO 1853 and ISO 2878.

Because the test pieces are simply and easily prepared, this method is particularly useful for rapidly

determining values which will give a general indication of quality when great accuracy is not required.

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.

ISO 18899:2013, Rubber — Guide to the calibration of test equipment
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:

— ISO Online browsing platform: available at https: //www .iso .org/obp
— IEC Electropedia: available at http: //www .electropedia .org/
3.1
insulation resistance

ratio of the direct

voltage applied to the electrodes to the total current between them at a given time after the application

of that voltage

Note 1 to entry: It is dependent upon both the volume and surface resistances of the test

...