IEC 60794-1-107:2025

Optical fibre cables - Part 1-107: Generic specification - Basic optical cable test procedures - Mechanical test methods - Torsion, method E7

IEC 60794-1-107:2025 applies to optical fibre cables for use with telecommunication equipment and devices employing similar techniques, and to cables having a combination of both optical fibres and electrical conductors. This document defines test procedures used in establishing uniform requirements for torsion performance. Refer to IEC 60794-1-2 for a reference guide to test methods and for general requirements and definitions.
NOTE Throughout this document, the wording "optical cable" also includes optical fibre units, microduct fibre units, etc.
This first edition partially cancels and replaces IEC 60794-1-21:2015. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to IEC 60794-1-21:2015:
a) Update of the typical test length according to the different types of cables;
b) Update of Figure 2 by loading weights to cable gripping fixture.

Câbles à fibres optiques - Partie 1-107 : Spécification générique - Procédures fondamentales d'essais des câbles optiques - Méthodes d'essais mécaniques - Torsion, méthode E7

IEC 60794-1-107:2025 s'applique aux câbles à fibres optiques destinés à être utilisés dans les équipements de télécommunications et les dispositifs utilisant des techniques analogues, ainsi qu'aux câbles constitués de fibres optiques d'une part et de conducteurs électriques d'autre part. L'objet du présent document est de définir les procédures d'essai utilisées en vue d'établir des exigences uniformes pour la tenue à la torsion. Voir l'IEC 60794-1-2 à titre de guide de référence pour les méthodes d'essai, ainsi que les exigences générales et les définitions.
NOTE Dans le présent document, l'expression "câble optique" englobe également des assemblages de fibres optiques, des assemblages de fibres en microconduits, etc. Cette première édition annule et remplace partiellement l'IEC 60794-1-21:2015 et elle constitue une révision technique.
Cette édition inclut les modifications techniques majeures suivantes par rapport à l'IEC 60794‑1‑21:2015:
a) mise à jour de la longueur d'essai typique en fonction des différents types de câbles;
b) mise à jour de la Figure 2 en appliquant une charge de poids au dispositif de préhension du câble.

General Information

• Status: Published
• Publication Date: 16-Oct-2025
• ICS: 33.180.10 - Fibres and cables
• Technical Committee: SC 86A - Fibres and cables
• Current Stage: PPUB - Publication issued
• Start Date: 17-Oct-2025
• Completion Date: 07-Nov-2025

Relations

• Replaces: IEC 60794-1-21:2015 - Optical fibre cables - Part 1-21: Generic specification - Basic optical cable test procedures - Mechanical tests methods
• Effective Date: 12-Jan-2024

Standards Content (Sample)

IEC 60794-1-107 ®
Edition 1.0 2025-10
INTERNATIONAL
STANDARD
Optical fibre cables -
Part 1-107: Generic specification - Basic optical cable test procedures -
Mechanical test methods - Torsion, method E7
ICS 33.180.10  ISBN 978-2-8327-0764-7

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
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.

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(IEV) online.
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CONTENTS
FOREWORD . 2
INTRODUCTION . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Method E7 – Torsion . 5
4.1 Object . 5
4.2 Sample . 5
4.3 Apparatus . 6
4.4 Procedure . 7
4.5 Requirements . 9
4.6 Details to be specified . 9
4.7 Details to be reported . 9
Bibliography . 10

Figure 1 – Cable torsion apparatus . 6
Figure 2 – Cable torsion apparatus with tension applied . 6
Figure 3 – Alternative cable torsion apparatus with tension applied . 7

Table 1 – Typical test length . 8

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
Optical fibre cables -
Part 1-107: Generic specification - Basic optical cable test procedures -
Mechanical test methods - Torsion, method E7

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) IEC draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). IEC takes no position concerning the evidence, validity or applicability of any claimed patent rights in
respect thereof. As of the date of publication of this document, IEC had not received notice of (a) patent(s), which
may be required to implement this document. However, implementers are cautioned that this may not represent
the latest information, which may be obtained from the patent database available at https://patents.iec.ch. IEC
shall not be held responsible for identifying any or all such patent rights.
IEC 60794-1-107 has been prepared by subcommittee 86A: Fibres and cables, of IEC technical
committee 86: Fibre optics. It is an International Standard.
This first edition partially cancels and replaces IEC 60794-1-21:2015. This edition constitutes
a technical revision.
This edition includes the following significant technical changes with respect to
IEC 60794-1-21:2015:
a) Update of the typical test length according to the different types of cables;
b) Update of Figure 2 by loading weights to cable gripping fixture.
The text of this International Standard is based on the following documents:
Draft Report on voting
86A/2615/FDIS 86A/2627/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/publications.
A lis
...

IEC 60794-1-107 ®
Edition 1.0 2025-10
NORME
INTERNATIONALE
Câbles à fibres optiques -
Partie 1-107: Spécification générique - Procédures fondamentales d'essais des
câbles optiques - Méthodes d'essais mécaniques - Torsion, méthode E7
ICS 33.180.10  ISBN 978-2-8327-0764-7

Droits de reproduction réservés. Sauf indication contraire, aucune partie de cette publication ne peut être reproduite ni
utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie et
les microfilms, sans l'accord écrit de l'IEC ou du Comité national de l'IEC du pays du demandeur. Si vous avez des
questions sur le copyright de l'IEC ou si vous désirez obtenir des droits supplémentaires sur cette publication, utilisez
les coordonnées ci-après ou contactez le Comité national de l'IEC de votre pays de résidence.

IEC Secretariat Tel.: [phone]
3, rue de Varembé [e-mail]
CH-1211 Geneva 20 www.iec.ch
Switzerland
A propos de l'IEC
La Commission Electrotechnique Internationale (IEC) est la première organisation mondiale qui élabore et publie des
Normes internationales pour tout ce qui a trait à l'électricité, à l'électronique et aux technologies apparentées.

A propos des publications IEC
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SOMMAIRE
AVANT-PROPOS . 2
INTRODUCTION . 4
1 Domaine d'application . 5
2 Références normatives . 5
3 Termes et définitions. 5
4 Méthode E7 – Torsion . 5
4.1 Objet . 5
4.2 Échantillon . 5
4.3 Appareillage . 6
4.4 Procédure . 7
4.5 Exigences . 9
4.6 Informations détaillées à spécifier . 9
4.7 Informations détaillées à consigner. 9
Bibliographie . 10

Figure 1 – Appareillage de torsion de câble . 6
Figure 2 – Appareillage de torsion de câble avec application de tension. 6
Figure 3 – Autre appareillage de torsion de câble avec application de tension . 7

Tableau 1 – Longueur d'essai typique . 8

COMMISSION ÉLECTROTECHNIQUE INTERNATIONALE
____________
Câbles à fibres optiques -
Partie 1-107: Spécification générique - Procédures fondamentales
d'essais des câbles optiques - Méthodes d'essais mécaniques - Torsion,
méthode E7
AVANT-PROPOS
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L'IEC ne saurait être tenue pour responsable de ne pas avoir identifié de tels droits de brevets.
L'IEC 60794-1-107 a été établie par le sous-comité 86A: Fibres et câbles, du comité
d'études 86 de l'IEC: Fibres optiques. Il s'agit d'une Norme internationale.
Cette première édition annule et remplace partiellement l'IEC 60794-1-21:2015 et elle constitue
une révision technique.
Cette édition inclut les modifications techniques majeures suivantes par rapport à
l'IEC 60794-1-21:2015:
a) mise à jour de la longueur d'essai typique en fonction des différents types de câbles;
b) mise à jour de la Figure 2 en appliquant une charge de poids au dispositif de préhension du
câble.
Le texte de cette Norme internationale est issu des documents suivants:
Projet Rapport de vote
86A/2615/FDIS 86A/2627/RVD
Le rapport de vote indiqué dans le tableau ci-dessus donne toute information sur le vote ayant
abouti à son approbation.
La langue employée pour l'élaboration de cette Norme internationale est l'anglais.
Ce document a été rédigé selon les Directives ISO/IEC, Partie 2, il a été développé selon les
Directives ISO/IEC, Partie 1 et les Directives ISO/IEC, Supplément IEC, disponibles sous
www.iec.ch/members_experts/refdocs. Les principaux types de documents développés par
l'IEC sont décrits plus en détail sous www.iec.ch/publications.
Une liste de toutes les parties de la série IEC 60794, publiées sous le titre général Câbles à
fibres optiques, se trouve sur le site web de l'IEC.
Le comité a décidé que le contenu de ce document ne sera pas modifié avant la date de stabilité
indiquée sur le site web de l'IEC sous webstore.iec.ch dans les données relatives au document
recherché. À cette date, le document sera
– reconduit,
– supprimé, ou
– révisé.
INTRODUCTION
Le présent document annule et remplace la méthode E7 de l'IEC 607
...

IEC 60794-1-107 ®
Edition 1.0 2025-10
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Optical fibre cables -
Part 1-107: Generic specification - Basic optical cable test procedures -
Mechanical test methods - Torsion, method E7

Câbles à fibres optiques -
Partie 1-107: Spécification générique - Procédures fondamentales d'essais des
câbles optiques - Méthodes d'essais mécaniques - Torsion, méthode E7
ICS 33.180.10  ISBN 978-2-8327-0764-7

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.

Droits de reproduction réservés. Sauf indication contraire, aucune partie de cette publication ne peut être reproduite ni
utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie et
les microfilms, sans l'accord écrit de l'IEC ou du Comité national de l'IEC du pays du demandeur. Si vous avez des
questions sur le copyright de l'IEC ou si vous désirez obtenir des droits supplémentaires sur cette publication, utilisez
les coordonnées ci-après ou contactez le Comité national de l'IEC de votre pays de résidence.

IEC Secretariat Tel.: [phone]
3, rue de Varembé [e-mail]
CH-1211 Geneva 20 www.iec.ch
Switzerland
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 - IEC Products & Services Portal - products.iec.ch
webstore.iec.ch/advsearchform Discover our powerful search engine and read freely all the
The advanced search enables to find IEC publications by a publications previews, graphical symbols and the glossary.
variety of criteria (reference number, text, technical With a subscription you will always have access to up to date
committee, …). It also gives information on projects, content tailored to your needs.
replaced and withdrawn publications.
Electropedia - www.electropedia.org
IEC Just Published - webstore.iec.ch/justpublished The world's leading online dictionary on electrotechnology,
Stay up to date on all new IEC publications. Just Published containing more than 22 500 terminological entries in English
details all new publications released. Available online and and French, with equivalent terms in 25 additional languages.
once a month by email. Also known as the International Electrotechnical Vocabulary
(IEV) online.
IEC Customer Service Centre - webstore.iec.ch/csc
If you wish to give us your feedback on this publication or
need further assistance, please contact the Customer
Service Centre: [e-mail].
A propos de l'IEC
La Commission Electrotechnique Internationale (IEC) est la première organisation mondiale qui élabore et publie des
Normes internationales pour tout ce qui a trait à l'électricité, à l'électronique et aux technologies apparentées.

A propos des publications IEC
Le contenu technique des publications IEC est constamment revu. Veuillez vous assurer que vous possédez l’édition la
plus récente, un corrigendum ou amendement peut avoir été publié.

Recherche de publications IEC -  IEC Products & Services Portal - products.iec.ch
webstore.iec.ch/advsearchform Découvrez notre puissant moteur de recherche et consultez
La recherche avancée permet de trouver des publications gratuitement tous les aperçus des publications, symboles
IEC en utilisant différents critères (numéro de référence, graphiques et le glossaire. Avec un abonnement, vous aurez
texte, comité d’études, …). Elle donne aussi des toujours accès à un contenu à jour adapté à vos besoins.
informations sur les projets et les publications remplacées
ou retirées. Electropedia - www.electropedia.org

Le premier dictionnaire d'électrotechnologie en ligne au
IEC Just Published - webstore.iec.ch/justpublished monde, avec plus de 22 500 articles terminologiques en
Restez informé sur les nouvelles publications IEC. Just anglais et en français, ainsi que les termes équivalents
Published détaille les nouvelles publications parues. dans 25 langues additionnelles. Egalement appelé
Disponible en ligne et une fois par mois par email. Vocabulaire Electrotechnique International (IEV) en ligne.

Service Clients - webstore.iec.ch/csc
Si vous désirez nous donner des commentaires sur cette
publication ou si vous avez des questions contactez-
nous: [e-mail].
CONTENTS
FOREWORD . 2
INTRODUCTION . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Method E7 – Torsion . 5
4.1 Object . 5
4.2 Sample . 5
4.3 Apparatus . 6
4.4 Procedure . 7
4.5 Requirements . 9
4.6 Details to be specified . 9
4.7 Details to be reported . 9
Bibliography . 10

Figure 1 – Cable torsion apparatus . 6
Figure 2 – Cable torsion apparatus with tension applied . 6
Figure 3 – Alternative cable torsion apparatus with tension applied . 7

Table 1 – Typical test length . 8

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
Optical fibre cables -
Part 1-107: Generic specification - Basic optical cable test procedures -
Mechanical test methods - Torsion, method E7

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) IEC draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). IEC takes no position concerning the evidence, validity or applicability of any claimed patent rights in
respect thereof. As of the date of publication of this document, IEC had not received notice of (a) patent(s), which
may be required to implement this document. However, implementers are cautioned that this may not represent
the latest information, which may be obtained from the patent database available at https://patents.iec.ch. IEC
shall not be held responsible for identifying any or all such patent rights.
IEC 60794-1-107 has been prepared by subcommittee 86A: Fibres and cables, of IEC technical
committee 86: Fibre optics. It is an International Standard.
This first edition partially cancels and replaces IEC 60794-1-21:2015. This edition constitutes
a technical revision.
This edition includes the following significant technical changes with respect to
IEC 60794-1-21:2015:
a) Update of the typical test length according to the different types of cables;
b) Update of Figure 2 by loading weights to cable gripping fixture.
The text of this International Standard is based on the following documents:
Draft Report on voting
86A/2615/FDIS 86A/2627/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/publications.
A list of all parts in the IEC 60794 series, published under the general title Optical fibre cables,
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 webstore.iec.ch in the data related to the
specific document. At this date, the document will be
– reconfirmed,
– withdrawn, or
– revised.
INTRODUCTION
This document cancels and replaces method E7 of IEC 60794-1-21:2015, which will be
withdrawn. It includes an editorial revision, based on the new structure and numbering system
for optical fibre cable test methods. Additionally, technical changes were implemented. The
mechanical tests contained in IEC 60794-1-21:2015 will be individually numbered in the
IEC 60794-1-1xx series. Each test method is now considered to be an individual document
rather than part of a multi-test method compendium. Full cross-reference details are given in
IEC 60794-1-2.
1 Scope
This part of IEC 60794 applies to optical fibre cables for use with telecommunication equipment
and devices employing similar techniques, and to cables having a combination of both optical
fibres and electrical conductors.
This document defines test procedures used in establishing uniform requirements for torsion
performance.
Refer to IEC 60794-1-2 for a reference guide to test methods and for general requirements and
definitions.
NOTE Throughout this document, the wording "optical cable" also includes optical fibre units, microduct fibre units,
etc.
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 60793-1-46:2024, Optical fibres - Part 1-46: Measurement methods and test procedures -
Monitoring of changes in attenuation
IEC 60794-1-1, Optical fibre cables - Part 1-1: Generic specification - General
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60794-1-1 apply.
ISO and IEC maintain terminology 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
4 Method E7 – Torsion
4.1 Object
This test method is intended to establish the ability of a fibre optic cable to withstand mechanical
twisting. The primary purpose of this procedure is to measure any variation in the attenuation
of a fibre when the cable is subjected to torsional forces external to the cable sheath. The
secondary purpose is to evaluate the possibility of physical damage that can occur as a result
of such stresses.
4.2 Sample
The sample of fibre optic cable shall be long enough to permit the appropriate clamping and
twisting and be long enough to permit a change in attenuation measurements as required by
the relevant specification.
4.3 Apparatus
The twisting apparatus consists essentially of two cable gripping devices or clamps, one fixed
and one that can rotate, supported as appropriate, the distance between them being adjustable.
The rotating clamp is connected to suitable turning equipment (e.g. a torquing lever). Any clamp
supports, gripping devices or torquing equipment used shall all be such as to permit access to
both ends of the cable sample for optical testing as can be required. Suitable apparatus is
illustrated in Figure 1, Figure 2 and Figure 3.

Figure 1 – Cable torsion apparatus

Figure 2 – Cable torsion apparatus with tension applied
Figure 3 – Alternative cable torsion apparatus with tension applied
The cable gripping devices shall be such that
– they are tightened around the cable sufficiently to prevent movement within the grip,
– the clamps hold the cable firmly in a straight line,
– the clamps do not induce localized twisting damage on the cable caused by the inside edge
of the clamp or undue localized concentration of pressure on the cable,
– the process of clamping does not induce any significant or accurately measurable
attenuation increase (or no more than a negligible increase) in the sample.
If either required by the relevant specification or to minimize sample bending from a straight
configuration, or both, use weights or an appropriate loading mechanism to apply a tensile load
to the cable gripping fixture (see Figure 2 and Figure 3). In any case, one end of the gripping
fixtures shall be free to move longitudinally to respond to foreshortening of the cable.
The apparatus shall include attenuation equipment to measure the change in optical throughput
as required in the relevant specification, and as specified in IEC 60793-1-46:2024, Annex A,
method A (change in attenuation by transmitted power).
4.4 Procedure
Install the sample in the test apparatus such that test length L (see Figure 1, Figure 2 and
Figure 3) is as described in Table 1 or as described in the relevant specification.
Table 1 – Typical test length
Cable type Typical test length
Outdoor cable (stranded wire armor) No more than 10,0 m
Outdoor cable (others) 125 times the cable diameter but no more than 2,0 m
Indoor cable – intended for multi-fibre optical cable 125 times the cable diameter but no more than 2,0 m
Indoor cable – intended for simplex and duplex optical 125 times the cable diameter but no more than 1,0 m
cable
Indoor cable – intended for terminated cable 125 times the cable diameter but no less than 0,3 m
assemblies
Indoor-outdoor cable – intended for flame retardant 125 times the cable diameter but no more than 2,0 m
outdoor cable
Indoor-outdoor cable – intended for universal cable Same as indoor cable intended for different types as
and weatherised indoor cable specified as above

Ensure that no initial stress is applied to the sample. Except for the necessary twisting operation,
do not move or disturb the sample ends throughout the test. Intrinsically torque-resistant cables
can require a longer test length to be agreed between the customer and the supplier.
Minimize sample sag (Figure 1 or Figure 2) or vertical deviation from a straight line (Figure 3)
as much as possible.
If change of optical performance is required by the relevant specification, measure the
unstressed sample. Compare results with those after clamping to ensure that the clamping has
not significantly degraded the cable performance.
If not prohibited by the relevant specification, sample sag or bend may be minimized by
supporting the test length or by applying tension to the sample cable. If required, apply tension
as specified in the relevant specification to keep the sample straight.
If a determination of change in attenuation is required by the relevant specification, measure
optical output power for the sample after clamping and application of tensile load, if any.
Rotate the movable cable clamp as follows:
a) 180° clockwise;
b) return to the starting position;
c) 180° counterclockwise;
d) return to the starting position.
This total four-part movement constitutes one cycle. Complete each cycle within 1 min maximum,
for a total of 10 cycles, unless otherwise specified in the relevant specification. If the rotations
and measurements require more than 1 min per cycle, the effective duration of the cycle shall
be reported.
NOTE For cables with a larger outer diameter (typically above 25 mm), a longer cycle time can be agreed between
the customer and the supplier.
If the change in attenuation during test is specified in the relevant specification, the change in
attenuation shall be measured in the first and last cycle after the cable has reached the extreme
position (180° clockwise or 180° counterclockwise) and has been held for at least 10 s.
After all cycles have been performed, allow the sample to rest for a minimum period of 5 min.
Measure the final acceptance criteria parameters. If necessary, the sample may be removed
from the apparatus for visual examination using normal corrected vision.
4.5 Requirements
The acceptance criteria for the s
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