SIST EN IEC 60793-1-47:2018

Optical fibres - Part 1-47: Measurement methods and test procedures - Macrobending loss (IEC 60793-1-47:2017)

This part of IEC 60793 establishes uniform requirements for measuring the macrobending
loss of single-mode fibres (class B) at 1 550 nm or 1 625 nm, category A1 multimode fibres at
850 nm or 1 300 nm, and category A3 and A4 multimode fibres at 650 nm, 850 nm or
1 300 nm, thereby assisting in the inspection of fibres and cables for commercial purposes.
This document gives two methods for measuring macrobending sensitivity:
• Method A – Fibre winding, pertains to class B single-mode fibres and category A1
multimode fibres.
• Method B – Quarter circle bends, pertains to category A3 and A4 multimode fibres.
For both of these methods, the macrobending loss can be measured utilizing general fibre
attenuation techniques, for example the power monitoring technique (see Annex A) or the
cut-back technique (see Annex B). Methods A and B are expected to produce different results
if they are applied to the same fibre. This is because the key difference between the two
methods is the deployment, including the bend radius and length of fibre that is bent. The
reason for the difference is that A3 and A4 multimode fibres are expected to be deployed in
short lengths with a smaller number of bends per unit fiber length compared to single-mode
and category A1 multimode fibres.
In this document, the "curvature radius" is defined as the radius of the suitable circular
shaped support (e.g. mandrel or guiding groove on a flat surface) on which the fibre can be
bent.
In addition, informative Annex E has been added to approximate bend loss for class B singlemode
fibres across a broad wavelength range at various effective bends.

Lichtwellenleiter - Teil 1-47: Messmethoden und Prüfverfahren - Makrobiegeverlust (IEC 60793-1-47:2017)

Fibres optiques - Partie 1-47: Méthodes de mesure et procédures d'essai - Pertes par macrocourbures (IEC 60793-1-47:2017)

NEW!IEC 60793-1-47:2017 est disponible sous forme de IEC 60793-1-47:2017 RLV qui contient la Norme internationale et sa version Redline, illustrant les modifications du contenu technique depuis l'édition précédente.

IEC 60793-1-47:2017 établit des exigences uniformes pour la mesure des pertes par macrocourbures pour les fibres optiques unimodales (classe B) à 1 550 nm ou 1 625 nm, pour les fibres multimodales de catégorie A1 à 850 nm ou 1 300 nm, et les fibres multimodales des catégories A3 et A4 à 650 nm, 850 nm ou 1 300 nm, contribuant ainsi au contrôle des fibres et câbles dans des relations commerciales. Le présent document décrit deux méthodes destinées à mesurer la sensibilité aux macrocourbures:
- Méthode A – Enroulement de fibre, se rapporte aux fibres unimodales de classe B et aux fibres multimodales de catégorie A1.
- Méthode B – Courbures d'un quart de cercle, se rapporte aux fibres multimodales de catégories A3 et A4.
Pour les deux méthodes, les pertes par macrocourbures peuvent être mesurées par des techniques générales d'affaiblissement des fibres, par exemple la technique de mesure de la puissance (voir Annexe A) ou la technique de la fibre coupée (voir Annexe B). Les méthodes A et B sont susceptibles de produire des résultats différents si elles sont appliquées à la même fibre. Ceci est dû au fait que la différence fondamentale entre les deux méthodes réside dans la façon de les déployer, comprenant à la fois le rayon de courbure et la longueur de fibre courbée. La raison de cette différence repose sur le fait que les fibres multimodales des catégories A3 et A4 sont conçues pour être installées sur de petites longueurs et avec un faible nombre de courbures par unité de longueur de fibre par rapport aux fibres unimodales et aux fibres multimodales de la catégorie A1.  Dans le présent document, le "rayon de courbure" est défini comme le rayon du support adapté de forme circulaire (par exemple, un mandrin ou une rainure de guidage sur une surface plane) sur lequel la fibre peut être courbée.  En outre, l'Annexe E (informative) a été ajoutée pour présenter une approximation des pertes par courbures pour des fibres unimodales de classe B sur une large plage de longueurs d'onde pour différentes courbures effectives. Cette quatrième édition annule et remplace la troisième édition publiée en 2009 dont elle constitue une révision technique.  Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
- l'Annexe A a été renumérotée Annexe D;
- une nouvelle Annexe A portant sur la technique de la mesure de la puissance transmise a été introduite;
- l'Annexe B portant sur la technique de la fibre coupée a été introduite;
- l'Annexe C portant sur les exigences relatives aux caractéristiques des sources optiques pour une mesure des fibres multimodales de catégorie A1 a été introduite;
- l'Annexe E portant sur l'approximation des pertes par macrocourbures utilisant des plaques parallèles (deux points) a été introduite.
Mots clés : macrocourbures pour les fibres optiques unimodales

Optična vlakna - 1-47. del: Merilne metode in preskusni postopki - Izgube zaradi makro upogibov (IEC 60793-1-47:2017)

Ta del standarda IEC 60793 določa enotne zahteve za merjenje izgube zaradi makro upogibov za enorodna vlakna (razred B) pri 1550 nm ali 1625 nm, večrodna vlakna kategorije A1 pri 850 nm ali 1300 nm ter večrodna vlakna kategorij A3 in A4 pri 650 nm, 850 nm ali 1300 nm, pri čemer pomaga pri pregledu vlaken in kablov za komercialne namene.
Ta dokument podaja dve metodi merjenja občutljivosti za makro upogibe:
• metoda A – navijanje vlaken: uporablja se za enorodna vlakna razreda B in večrodna vlakna razreda A1;
• metoda B – upogib za četrtino kroga: uporablja se za večrodna vlakna kategorij A3 in A4.
Pri obeh metodah je izgube zaradi upogibov mogoče izračunati s splošnimi tehnikami slabljenja vlaken, npr. s tehniko nadzora moči (glej dodatek A) ali tehniko rezanja (glej dodatek B). Če se pri metodah A in B uporablja isto vlakno, se pričakuje, da bodo rezultati različni. Ključna razlika med obema metodama je namreč v uporabi, vključno s polmerom upogiba in dolžino vlakna, na katerem se izvaja upogib. Razlog za razliko je v tem, da se za večrodna vlakna kategorij A3 in A4 v primerjavi z enorodnimi vlakni in večrodnimi vlakni kategorije A1 pričakuje, da bodo uporabljena s kratko dolžino in manj upogibi na enoto dolžine vlakna.
V tem dokumentu je »polmer upogiba« opredeljen kot polmer primernega nosilca v obliki kroga (npr. vpenjalna os ali usmerjevalni žleb na ravni površini), na katerem je mogoče upogniti vlakno.
Poleg tega je bil za približne izgube zaradi upogibov za enorodna vlakna razreda B, ki vključujejo širok razpon valovnih dolžin pri različnih učinkovitih upogibih, dodan informativni dodatek E.

General Information

• Status: Published
• Publication Date: 05-Mar-2018
• ICS: 33.180.10 - Fibres and cables
• Technical Committee: MOC - Mobile Communications
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 14-Feb-2018
• Due Date: 21-Apr-2018
• Completion Date: 06-Mar-2018
• Ref Project: EN IEC 60793-1-47:2018 - Optical fibres - Part 1-47: Measurement methods and test procedures - Macrobending loss

Relations

• Replaces: SIST EN 60793-1-47:2009 - Optical fibres - Part 1-47: Measurement methods and test procedures - Macrobending loss (IEC 60793-1-47:2009)
• Effective Date: 13-Feb-2018
• Replaces: SIST EN 60793-1-47:2009 - Optical fibres - Part 1-47: Measurement methods and test procedures - Macrobending loss (IEC 60793-1-47:2009)
• Effective Date: 07-Jun-2022

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN IEC 60793-1-47:2018
01-april-2018
1DGRPHãþD
SIST EN 60793-1-47:2009
2SWLþQDYODNQDGHO0HULOQHPHWRGHLQSUHVNXVQLSRVWRSNL,]JXEH]DUDGL
PDNURXSRJLERY,(&
Optical fibres - Part 1-47: Measurement methods and test procedures - Macrobending
loss (IEC 60793-1-47:2017)
Lichtwellenleiter - Teil 1-47: Messmethoden und Prüfverfahren - Makrobiegeverlust (IEC
60793-1-47:2017)
Fibres optiques - Partie 1-47: Méthodes de mesure et procédures d'essai - Pertes par
macrocourbures (IEC 60793-1-47:2017)
Ta slovenski standard je istoveten z: EN IEC 60793-1-47:2018
ICS:
33.180.10 2SWLþQDYODNQDLQNDEOL Fibres and cables
SIST EN IEC 60793-1-47:2018 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN IEC 60793-1-47:2018

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SIST EN IEC 60793-1-47:2018


EUROPEAN STANDARD EN IEC 60793-1-47

NORME EUROPÉENNE

EUROPÄISCHE NORM
February 2018
ICS 33.180.10 Supersedes EN 60793-1-47:2009
English Version
Optical fibres - Part 1-47: Measurement methods and test
procedures - Macrobending loss
(IEC 60793-1-47:2017)
Fibres optiques - Partie 1-47: Méthodes de mesure et Lichtwellenleiter - Teil 1-47: Messmethoden und
procédures d'essai - Pertes par macrocourbures Prüfverfahren - Makrobiegeverlust
(IEC 60793-1-47:2017) (IEC 60793-1-47:2017)
This European Standard was approved by CENELEC on 2017-11-15. 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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, 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
© 2018 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
 Ref. No. EN IEC 60793-1-47:2018 E

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SIST EN IEC 60793-1-47:2018
EN IEC 60793-1-47:2018 (E)


European foreword
The text of document 86A/1823/FDIS, future edition 2 of IEC 60793-1-47, prepared by IEC/SC 86A
"Fibres and cables", of IEC/TC 86 "Fibre optics" was submitted to the IEC-CENELEC parallel vote and
approved by CENELEC as EN IEC 60793-1-47:2018.

The following dates are fixed:
• latest date by which the document has to be (dop) 2018-08-15
implemented at national level by
publication of an identical national
standard or by endorsement
(dow) 2020-11-15
• latest date by which the national
standards conflicting with the
document have to be withdrawn

This document supersedes EN 60793-1-47:2009.

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 60793-1-47:2017 was approved by CENELEC as a
European Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standards indicated:

IEC 60793-1-40 NOTE Harmonized as EN 60793-1-40.
IEC 60793-1-46 NOTE Harmonized as EN 60793-1-46.
IEC 60793-2-50 NOTE Harmonized as EN 60793-2-50.

2

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SIST EN IEC 60793-1-47:2018
EN IEC 60793-1-47:2018 (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 60793 series Optical fibres - series
IEC 60793-1-1 2017 Optical fibres - Part 1-1: Measurement EN 60793-1-1 2017
methods and test procedures - General
and guidance
IEC 60793-2 -  Optical fibres - Part 2: Product EN 60793-2 -
specifications - General
IEC 60793-2-10 -  EN 60793-2-10 -
IEC 61280-1-4 -  Fibre optic communication subsystem test EN 61280-1-4 -
procedures -- Part 1-4: General
communication subsystems - Light source
encircled flux measurement method
IEC 61280-4-1 -  Fibre optic communication subsystem test EN 61280-4-1 -
procedures -- Part 4-1: Installed cable plant
- Multimode attenuation measurement


3

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SIST EN IEC 60793-1-47:2018




IEC 60793-1-47

®


Edition 4.0 2017-10




INTERNATIONAL



STANDARD




NORME



INTERNATIONALE
colour

inside










Optical fibres –

Part 1-47: Measurement methods and test procedures – Macrobending loss




Fibres optiques –

Partie 1-47: Méthodes de mesure et procédures d'essai – Pertes par

macrocourbures















INTERNATIONAL

ELECTROTECHNICAL

COMMISSION


COMMISSION

ELECTROTECHNIQUE


INTERNATIONALE




ICS 33.180.10 ISBN 978-2-8322-4865-2



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

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SIST EN IEC 60793-1-47:2018
– 2 – IEC 60793-1-47:2017 © IEC 2017
CONTENTS
FOREWORD . 5
INTRODUCTION . 7
1 Scope . 8
2 Normative references . 8
3 Terms and definitions . 9
4 Apparatus . 9
4.1 Method A – Fibre winding . 9
4.2 Method B – Quarter circle bends . 9
4.3 Input system . 10
4.3.1 Optical source . 10
4.3.2 Optical launch arrangement . 10
4.4 Output system and detection . 12
4.4.1 Optical divider . 12
4.4.2 Optical detector . 12
4.4.3 Optical detection assembly . 13
4.4.4 Signal processing . 13
5 Specimen . 13
5.1 Specimen length . 13
5.1.1 Method A – Fibre winding . 13
5.1.2 Method B – Quarter circle bends. 13
5.2 Specimen end face . 13
6 Procedure . 13
6.1 Method A – Fibre winding . 13
6.1.1 General consideration . 13
6.1.2 Single-mode fibres . 14
6.1.3 Multimode (A1) fibres . 15
6.2 Method B – Quarter circle bends . 15
7 Calculations . 17
8 Results . 17
8.1 Information available with each measurement . 17
8.2 Information available upon request . 17
9 Specification information . 17
Annex A (normative) Change in transmittance by transmitted power technique . 19
A.1 Apparatus . 19
A.1.1 General . 19
A.2 Procedure . 20
A.3 Calculations . 20
Annex B (normative) Cut-back technique . 22
B.1 General . 22
B.2 Apparatus . 22
B.2.1 General apparatus for all fibres. 22
B.3 Procedure . 22
B.4 Calculations . 23
Annex C (normative) Requirements for the optical source characteristics for A1
multimode measurement . 24

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SIST EN IEC 60793-1-47:2018
IEC 60793-1-47:2017 © IEC 2017 – 3 –
C.1 Encircled flux (EF) . 24
C.2 Limits on encircled flux . 24
Annex D (informative) Small bend radius phenomena . 27
D.1 General . 27
D.2 Interference between propagating and radiating modes . 27
D.3 Polarization effects . 29
D.4 High power damage . 29
Annex E (informative) Parallel plate (2-point) macrobend loss approximation . 30
E.1 General . 30
E.2 Specimen . 30
E.3 Apparatus . 30
E.3.1 General . 30
E.3.2 Stepper motor control . 31
E.3.3 Movable plate . 31
E.3.4 Fixed plate . 31
E.4 Procedure . 32
E.5 Calculation . 32
E.6 Results . 32
E.7 Comparison of results with normative test . 33
Bibliography . 35

Figure 1 – Quarter circle guide groove in plate . 9
Figure 2 – General launch arrangement . 10
Figure 3 – Lens system . 11
Figure 4 – Launch fibre . 11
Figure 5 – Mode scrambler (for A4 fibre) . 12
Figure 6 – Multiple bends using stacked plates . 16
Figure A.1 – Measurement of change in optical transmittance using reference
specimen . 19
Figure A.2 – Measurement of change in optical transmittance using stabilized source . 20
Figure B.1 – Arrangement of equipment to perform loss measurement at one specified
wavelength . 22
Figure B.2 – Arrangement of equipment used to obtain a loss spectrum . 22
Figure C.1 – Encircled flux template example . 25
Figure D.1 – Loss curves versus curve fits . 28
Figure E.1 – Schematic of possible (two-point bend) apparatus . 31
Figure E.2 – Example of applying an exponential fit to the spectral data of a B6_a2
fibre . 33
Figure E.3 – Example of 2-point bend test data for a B6_a2 fibre . 33

Table 1 – Launch conditions for A2 to A4 fibres . 12
Table C.1 – Threshold tolerance . 25
Table C.2 – EF requirements for 50 µm core fibre cabling at 850 nm . 26
Table C.3 – EF requirements for 50 µm core fibre cabling at 1 300 nm . 26
Table C.4 – EF requirements for 62,5 µm core fibre cabling at 850 nm . 26
Table C.5 – EF requirements for 62,5 µm core fibre cabling at 1 300 nm . 26

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Table E.1 – Comparison of parallel plate (2-point) versus method A macrobend loss
measurement for a B6_b3 fibre at 10 mm diameter (ratio of mandrel / 2-point). 34

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SIST EN IEC 60793-1-47:2018
IEC 60793-1-47:2017 © IEC 2017 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

OPTICAL FIBRES –

Part 1-47: Measurement methods and test procedures –
Macrobending loss

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 60793-1-47 has been prepared by subcommittee 86A: Fibres and
cables, of IEC technical committee 86: Fibre optics.
This fourth edition cancels and replaces the third edition published in 2009. It constitutes a
technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) former Annex A has been renumbered to Annex D;
b) introduction of new Annex A on the transmitted power monitoring technique;
c) introduction of Annex B on the cut-back technique;
d) introduction of Annex C on the requirements for the optical source characteristics of
A1 multimode measurement;
e) introduction of Annex E on parallel plate (2-point) macrobend loss approximation.
The text of this International Standard is based on the following documents:

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SIST EN IEC 60793-1-47:2018
– 6 – IEC 60793-1-47:2017 © IEC 2017
FDIS Report on voting
86A/1823/FDIS 86A/1828/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.
This standard is to be read in conjunction with IEC 60793-1-1:2017.
A list of all parts of IEC 60793 series, published under the general title Optical fibres, 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.

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SIST EN IEC 60793-1-47:2018
IEC 60793-1-47:2017 © IEC 2017 – 7 –
INTRODUCTION
Publications in the IEC 60793-1 series concern measurement methods and test procedures as
they apply to optical fibres.
Within the same series, several different areas are grouped, but all numbers are possibly not
used, as follows:
Parts 1-10 to 1-19: General
Parts 1-20 to 1-29: Measurement methods and test procedures for dimensions
Parts 1-30 to 1-39: Measurement methods and test procedures for mechanical
characteristics
Parts 1-40 to 1-49: Measurement methods and test procedures for transmission and
optical characteristics
Parts 1-50 to 1-59: Measurement methods and test procedures for environmental
characteristics

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SIST EN IEC 60793-1-47:2018
– 8 – IEC 60793-1-47:2017 © IEC 2017
OPTICAL FIBRES –

Part 1-47: Measurement methods and test procedures –
Macrobending loss



1 Scope
This part of IEC 60793 establishes uniform requirements for measuring the macrobending
loss of single-mode fibres (class B) at 1 550 nm or 1 625 nm, category A1 multimode fibres at
850 nm or 1 300 nm, and category A3 and A4 multimode fibres at 650 nm, 850 nm or
1 300 nm, thereby assisting in the inspection of fibres and cables for commercial purposes.
This document gives two methods for measuring macrobending sensitivity:
• Method A – Fibre winding, pertains to class B single-mode fibres and category A1
multimode fibres.
• Method B – Quarter circle bends, pertains to category A3 and A4 multimode fibres.
For both of these methods, the macrobending loss can be measured utilizing general fibre
attenuation techniques, for example the power monitoring technique (see Annex A) or the
cut-back technique (see Annex B). Methods A and B are expected to produce different results
if they are applied to the same fibre. This is because the key difference between the two
methods is the deployment, including the bend radius and length of fibre that is bent. The
reason for the difference is that A3 and A4 multimode fibres are expected to be deployed in
short lengths with a smaller number of bends per unit fiber length compared to single-mode
and category A1 multimode fibres.
In this document, the "curvature radius" is defined as the radius of the suitable circular
shaped support (e.g. mandrel or guiding groove on a flat surface) on which the fibre can be
bent.
In addition, informative Annex E has been added to approximate bend loss for class B single-
mode fibres across a broad wavelength range at various effective bends.
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 (all parts), Optical fibres – Measurement methods and test procedures
IEC 60793-1-1:2017, Optical fibres – Part 1-1: Measurement methods and test procedures –
General and guidance
IEC 60793-2, Optical fibres – Part 2: Product specifications – General
IEC 60793-2-10, Optical fibres – Part 2-10: Product specifications – Sectional specification for
category A1 multimode fibres
IEC 61280-1-4, Fibre optic communication subsystem test procedures – Part 1-4: General
communication subsystems – Light source encircled flux measurement method
IEC 61280-4-1, Fibre-optic communication subsystem test procedures – Part 4-1: Installed
cable plant– Multimode attenuation measurement

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SIST EN IEC 60793-1-47:2018
IEC 60793-1-47:2017 © IEC 2017 – 9 –
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60793-2,
IEC 60793-1 (all parts) and IEC 60793-1-1 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
NOTE General definitions for fibres are provided in IEC 60793-2, definitions of the specified attributes are
contained in the relevant test methods standard of IEC 60793-1 (all parts), and general definitions for testing are
provided in IEC 60793-1-1.
4 Apparatus
4.1 Method A – Fibre winding
The apparatus consists of a tool (e.g. a mandrel or a guiding groove on a flat surface) able to
hold the sample bent with a radius as stated in the appropriate optical fibre sectional product
specification and a loss measurement instrument. Determine the macrobending loss at the
wavelength as stated in the appropriate sectional product specification by using either the
transmitted power monitoring technique (Annex A) or the cut-back technique (Annex B),
taking care of the appropriate launch condition for the specific fibre type.
4.2 Method B – Quarter circle bends
The apparatus consists of one or more plates, each containing one or more "guide grooves",
and a loss measurement instrument. The plates shall be designed to be stacked during the
test without contacting the sample fibre in a lower or higher plate; such contact will affect the
measurement results. Each guide groove shall have a quarter circle segment (i.e. 90°) as
shown in Figure 1. The bend radius r, i.e. the radius of the quarter circle segment, shall be
stated in the detail specification. The width of each guide groove is recommended to be 40 %
broader than the outer fibre diameter.
Determine the macrobending loss at the wavelength as stated in the appropriate sectional
product specification by using either the transmitted power monitoring technique (Annex A) or
the cut-back technique (Annex B), taking care of the appropriate launch condition for the
specific fibre type.
Guide groove
r
Bend
radius

IEC

Figure 1 – Quarter circle guide groove in plate

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