ISO 20615:2018

Fibre ropes — Electrostatic surface potential measuring method

This document specifies a method for determining the electrostatic charging propensity of fibre ropes by measuring the surface potential generated by tribocharging. This document is not intended to be used to evaluate the safety of ropes for use in explosive atmospheres as safety also depends on application conditions. The test method described in this document is only applicable to fibre ropes of diameter between 12 mm and 20 mm. The result obtained using this test method is valid only for the charging mechanism and parameters described in the test method. Charging can be different in end-use applications.

Cordages en fibres — Méthode de mesurage du potentiel électrostatique de surface

General Information

• Status: Published
• Publication Date: 07-Oct-2018
• ICS: 59.080.50 - Ropes
• Technical Committee: ISO/TC 38 - Textiles
• Drafting Committee: ISO/TC 38 - Textiles
• Current Stage: 6060 - International Standard published
• Due Date: 09-Jun-2018
• Completion Date: 08-Oct-2018

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 20615
First edition
2018-10
Fibre ropes — Electrostatic surface
potential measuring method
Cordages en fibres — Méthode de mesurage du potentiel
électrostatique de surface
Reference number
ISO 20615:2018(E)
ISO 2018
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ISO 20615:2018(E)
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© ISO 2018

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ISO 20615:2018(E)
Contents Page

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

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

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

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

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

4 Principle ........................................................................................................................................................................................................................ 1

5 Test atmosphere.................................................................................................................................................................................................... 1

6 Apparatus ..................................................................................................................................................................................................................... 2

7 Preparation of specimens ........................................................................................................................................................................... 4

7.1 Specimen diameter .............................................................................................................................................................................. 4

7.2 Cutting ............................................................................................................................................................................................................ 4

7.3 Splicing rope specimen .................................................................................................................................................................... 4

7.4 Conditioning of specimen .............................................................................................................................................................. 5

8 Testing procedure ............................................................................................................................................................................................... 5

8.1 Rope specimen setting ..................................................................................................................................................................... 5

8.2 Measurement of surface potential generated by tribocharging ................................................................... 5

9 Test report ................................................................................................................................................................................................................... 6

Annex A (normative) Verification procedure and correction factor ................................................................................... 7

Annex B (informative) Example of test results........................................................................................................................................10

Annex C (informative) Information on the effect of parameters ..........................................................................................12

Annex D (informative) Interlaboratory test ...............................................................................................................................................14

Bibliography .............................................................................................................................................................................................................................17

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ISO 20615:2018(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.

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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 jointly by Technical Committee ISO/TC 38, Textiles, and Technical

Committee IEC/TC 101, Electrostatics. The draft was circulated for voting to the national bodies of both

ISO and IEC.

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.
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ISO 20615:2018(E)
Introduction

Heavy duty ropes can be made from metal wire or synthetic fibre or a combination of these two.

Historically, fibre ropes were commonly made of natural fibres such as cotton, flax, etc. Recently,

synthetic fibres have been used to make heavy duty ropes. Synthetic fibre ropes are lighter and stronger

than steel wire ropes and natural fibre ropes.

However, synthetic fibre can acquire electrostatic charge more easily compared to metal wire ropes or

natural fibre ropes.

To overcome this disadvantage, different methods have been applied to the manufacture of synthetic

fibre ropes, such as combining them with steel wire or blending with conductive yarn, etc. The

development of such ropes has taken place without a standard procedure for evaluating their

electrostatic propensity.

This document describes a test method that is used to determine tribocharging of fibre ropes by a

specified charging mechanism.

This testing method may not be representative of all possible charging mechanisms that are found in use.

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INTERNATIONAL STANDARD ISO 20615:2018(E)
Fibre ropes — Electrostatic surface potential measuring
method
1 Scope

This document specifies a method for determining the electrostatic charging propensity of fibre ropes

by measuring the surface potential generated by tribocharging.

This document is not intended to be used to evaluate the safety of ropes for use in explosive atmospheres

as safety also depends on application conditions.

The test method described in this document is only applicable to fibre ropes of diameter between

12 mm and 20 mm.

The result obtained using this test method is valid only for the charging mechanism and parameters

described in the test method. Charging can be different in end-use applications.
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 630-1, Structural steels — Part 1: General technical delivery conditions for hot-rolled products

ISO 1968, Fibre ropes and cordage — Vocabulary
3 Terms and definitions

For the purposes of this document, the terms and definitions given in ISO 1968 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/
4 Principle

A fibre rope specimen is cut to a designated length and both ends spliced by the short splice method

to make an endless loop. The rope specimen loop is mounted in a rope driving apparatus and passes

around friction cylinders and a non-contacting electrostatic voltmeter. As the rope makes contact with

the friction cylinders, rollers and pulleys, it becomes electrostatically charged. The resulting surface

potential is measured by the non-contacting electrostatic voltmeter.
5 Test atmosphere

Unless otherwise agreed or specified, the atmosphere for conditioning and testing shall be a

temperature of (23 ± 2) °C and a relative humidity of (25 ± 5) %.

A different temperature or relative humidity may be used as appropriate for different geographical

regions, but in any case, the atmosphere for conditioning and testing shall include the lowest relative

humidity expected in use.
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ISO 20615:2018(E)
6 Apparatus
6.1 Apparatus for tribocharging and measuring surface potential

One possible test apparatus is shown in Figure 1 as an example. Other apparatus capable of measuring

surface potential generated by tribocharging and recording such measurements over a period of time

may also be used after appropriate validation. For the validation, test a rope made of high modulus

polyethylene (HMPE) and compare the data with the example shown in Annex B.
The apparatus should be earthed. National electrical codes can be applicable.
Dimensions in millimetres with tolerance of ±4,0 mm
Key
1 rope specimen
2 friction cylinder (no rotation)
3 friction cylinder (no rotation)
4 loading roller
5 load
6 driving pulley
7 electrostatic voltmeter
8 motor
9 recording device
Figure 1 — Diagram of an example of the test apparatus

6.1.1 Friction cylinders, consisting of two friction cylinders (see Figure 1, key items 2 and 3), which

are fixed without rotation, and the rope specimen winds around the cylinders. The dimension of each

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ISO 20615:2018(E)

cylinder is 140 mm ± 3 mm in diameter and 180 mm ± 3 mm between flanges. The material is E275A

prescribed in ISO 630-1 and polishing roughness is an arithmetic mean roughness of 6,3 μm.

E275A represents a typical material in many applications. However, there can be other materials in

other applications that have different triboelectric charging characteristics.

If the application for ropes requires testing using other friction materials, such as polyamide resin for

example, other material for the friction cylinders may be used and shall be recorded in the test report.

6.1.2 Loading roller, hanging freely in the rope path (Figure 1, key item 4) and loaded with a mass

of 2,4 kg ± 0,3 kg (Figure 1 key item 5). The diameter of the roller is 46 mm ± 3 mm. The material is the

same as the friction cylinder material.
If a different load is used, record it in the test report.

6.1.3 Driving pulley, for driving the rope specimen in this testing apparatus along the rope path

(Figure 1, key item 6). The material is the same as the friction cylinder material.

6.1.4 Electrostatic potential measuring instrument, non-contacting electrostatic voltmeter as

shown in Figure 2, which may be either an electrostatic field meter calibrated to read surface voltage

using a known target geometry, or a direct reading electrostatic voltmeter (e.g. vibrating reed type).

— Range: 0 kV to 20 kV, both positive and negative polarity.
— Response time (0 % to 90 % full scale): ≤10 ms.

Verification shall be performed, and the correction factors shall be calculated according to Annex A.

Key
1 non-contacting electrostatic voltmeter
2 sensing point
3 rope specimen
4 mounting base
Figure 2 — Electrostatic voltmeter
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ISO 20615:2018(E)

6.1.5 Driving motor, with speed controlled by an inverter system. The rope running speed for this

measurement is 0,6 m/s ± 0,1 m/s.
If a different rope speed is used, record it in the test report.

6.1.6 Recording device, data logger connected to a personal computer, or other suitable device for

recording the output of the electrostatic voltmeter.
6.2 Neutralization apparatus, compressed gas or blown air ionizer, etc.
7 Preparation of specimens
7.1 Specimen diameter

The applicable diameter of ropes for this specific apparatus is from 12 mm to 20 mm. If the apparatus

design is changed, a wider range of diameters can be measured.

The maximum value of the rope diameter is determined by the maximum groove diameter of the

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