IEC 60793-1-40:2019

Optical fibres - Part 1-40: Attenuation measurement methods

IEC 60793-1-40:2019 establishes uniform requirements for measuring the attenuation of optical fibre, thereby assisting in the inspection of fibres and cables for commercial purposes. Four methods are described for measuring attenuation, one being that for modelling spectral attenuation:
– method A: cut-back;
– method B: insertion loss;
– method C: backscattering;
– method D: modelling spectral attenuation.
Methods A to C apply to the measurement of attenuation for all categories of the following fibres:
– class A multimode fibres;
– class B single-mode fibres.
Method C, backscattering, also covers the location, losses and characterization of point discontinuities. Method D is applicable only to class B fibres. Information common to all four methods appears in Clauses 1 to 11, and information pertaining to each individual method appears in Annexes A, B, C, and D, respectively. This second edition cancels and replaces the first edition published in 2001. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
a) Improvement of the description of measurement details for B6 fibre;
b) Improvement of the calibration requirements for A4 fibre;
c) Introduction of Annex E describing examples of short cable test results on A1 multimode fibres.
Keywords: measuring the attenuation of optical fibre

Fibres optiques - Partie 1-40: Méthodes de mesurage de l'affaiblissement

IEC 60793-1-40:2019 établit des exigences uniformes pour mesurer l'affaiblissement d'une fibre optique, contribuant ainsi au contrôle des fibres et des câbles dans les relations commerciales. Quatre méthodes sont décrites pour mesurer l'affaiblissement, parmi lesquelles une méthode pour modéliser l'affaiblissement spectral:
– méthode A: fibre coupée;
– méthode B: pertes d'insertion;
– méthode C: rétrodiffusion;
– méthode D: modélisation de l'affaiblissement spectral.
Les méthodes A à C s'appliquent au mesurage de l'affaiblissement pour toutes les catégories de fibres suivantes:
– fibres multimodales de classe A;
– fibres unimodales de classe B.
La méthode C, rétrodiffusion, s'applique aussi à la localisation, aux pertes et à la caractérisation des discontinuités ponctuelles. La méthode D s'applique uniquement aux fibres de classe B. Les informations communes à ces quatre méthodes sont présentées dans les Articles 1 à 11, et les informations propres à chaque méthode individuelle, sont présentées dans les Annexes A, B, C et D, respectivement. Cette deuxième édition annule et remplace la première édition parue en 2001 dont elle constitue une révision technique. La présente édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
a) Amélioration de la description des détails de mesurage pour les fibres B6;
b) Amélioration des exigences d'étalonnage pour les fibres A4;
c) Ajout de l'Annexe E qui décrit des exemples de résultats d'essai sur des câbles courts pour des fibres multimodales A1.
Mots-clés: mesurer l'affaiblissement d'une fibre optique

General Information

• Status: Published
• Publication Date: 26-Mar-2019
• ICS: 01 - GENERALITIES. TERMINOLOGY. STANDARDIZATION. DOCUMENTATION
• ICS: 33.180.10 - Fibres and cables
• Technical Committee: SC 86A - Fibres and cables
• Drafting Committee: WG 1 - TC 86/SC 86A/WG 1
• Current Stage: PPUB - Publication issued
• Start Date: 22-Mar-2019
• Completion Date: 27-Mar-2019

Relations

• Revises: IEC 60793-1-40:2001 - Optical fibres - Part 1-40: Measurement methods and test procedures - Attenuation
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC 60793-1-40 ®
Edition 2.0 2019-03
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Optical fibres –
Part 1-40: Measurement methods and test procedures – Attenuation
measurement methods
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
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IEC 60793-1-40 ®
Edition 2.0 2019-03
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Optical fibres –
Part 1-40: Measurement methods and test procedures – Attenuation

measurement methods
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 33.180.10 ISBN 978-2-8322-6770-7

– 2 – IEC 60793-1-40:2019 RLV © IEC 2019
CONTENTS
FOREWORD . 5
INTRODUCTION .
1 Scope . 8
2 Normative references . 8
3 Terms and definitions . 9
4 Calibration requirements . 10
5 Reference test method . 10
6 Apparatus . 10
7 Sampling and specimens . 10
7.1 Specimen length . 10
7.2 Specimen end face . 10
8 Procedure . 10
9 Calculations . 10
9.1 Methods A and B . 10
9.2 Method C . 11
9.3 Method D . 11
10 Results . 11
10.1 Information available with each measurement . 11
10.2 Information available upon request . 11
10.3 Method-specific additional information . 11
11 Specification information . 11
Annex A (normative) Requirements specific to method A – Cut-back . 12
A.1 General . 12
A.2 Apparatus . 12
A.2.1 General apparatus for all fibres. 12
A.2.2 Launch apparatus for all single-mode fibres . 14
A.2.3 Launch apparatus for A1 graded-index multimode fibres . 15
A.2.4 Launch apparatus for A2 to A4 step-index multimode fibres . 17
A.2.5 Calibration requirements . 18
A.3 Procedure . 19
A.4 Calculations . 19
Annex B (normative) Requirements specific to method B – Insertion loss . 20
B.1 General . 20
B.2 Apparatus . 20
B.2.1 General set-ups . 20
B.2.2 Apparatus common to method A (cut-back). 20
B.2.3 Additional apparatus specific to method B (insertion-loss) . 20
B.2.4 Calibration requirements . 20
B.3 Procedure . 20
B.4 Calculations . 21
Annex C (normative) Requirements specific to method C – Backscattering . 22
C.1 General . 22
C.2 Apparatus . 22
C.2.1 General . 22

C.2.2 Optical transmitter . 23
C.2.3 Launch conditions . 23
C.2.4 Optical splitter . 23
C.2.5 Optical receiver . 23
C.2.6 Pulse duration and repetition rate . 23
C.2.7 Signal processor . 23
C.2.8 Display . 24
C.2.9 Data interface (optional) . 24
C.2.10 Reflection controller (optional) . 24
C.2.11 Splices and connectors . 24
C.3 Sampling and specimens . 24
C.4 Procedure . 24
C.4.1 General . 24
C.4.2 Further steps for measuring attenuation. 26
C.4.3 Further steps for measuring point discontinuities . 26
C.4.4 Calibration . 28
C.5 Calculations . 28
C.6 Results . 28
Annex D (normative) Requirements specific to method D – Spectral attenuation
modelling . 30
D.1 General . 30
D.2 Apparatus . 30
D.3 Sampling and specimens . 30
D.4 Procedure . 30
D.5 Calculations . 31
D.6 Results . 31
Annex E (informative) Examples of short cable test results on A1 multimode fibres . 33
Bibliography . 35

Figure A.1 – Arrangement of equipment to make for loss measurement at one
a specified wavelength . 12
Figure A.2 – Arrangement of equipment used to obtain loss spectrum . 13
Figure A.3 – General launch arrangement . 13
Figure A.4 – Limited phase space launch optics . 16
Figure A.5 – Two examples of optical fibre scramblers . 17
Figure A.6 – Lens system . 17
Figure A.7 – Launch fibre . 18
Figure A.8 – Mode scrambler (for A.4 fibre) . 18
Figure A.9 – A wide-spectrum source (line "b") could lead to attenuation measurement
errors due to sharp variations on spectral attenuation of polymer-core fibres (line "a") . 19
Figure B.1 – Calibration of insertion loss measurement set . 21
Figure B.2 – Measurement of insertion loss . 21
Figure C.1 – Block diagram of an OTDR . 22
Figure C.2 – Schematic OTDR trace for a "uniform" specimen preceded by a
dead-zone fibre . 25
Figure C.3 – Schematic OTDR trace for a "uniform" specimen not preceded by a dead-
zone fibre . 25

– 4 – IEC 60793-1-40:2019 RLV © IEC 2019
Figure C.4 – Schematic OTDR trace showing apparent loss due to point discontinuities,
one reflective and one non-reflective . 27
Figure C.5 – Schematic of an expanded OTDR trace showing two point discontinuities,
one with apparent gain, and another with no apparent loss or gain . 27
Figure E.1 – Example of attenuation coefficient tests on A1a.1 fibre .
...

IEC 60793-1-40 ®
Edition 2.0 2019-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Optical fibres –
Part 1-40: Attenuation measurement methods

Fibres optiques –
Partie 1-40: Méthodes de mesurage de l'affaiblissement

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
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About the IEC
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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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committee,…). It also gives information on projects, replaced and French, with equivalent terms in 16 additional languages.
and withdrawn publications. Also known as the International Electrotechnical Vocabulary

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IEC publications issued since 2002. Some entries have been
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IEC 60793-1-40 ®
Edition 2.0 2019-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Optical fibres –
Part 1-40: Attenuation measurement methods

Fibres optiques –
Partie 1-40: Méthodes de mesurage de l'affaiblissement

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 33.180.10 ISBN 978-2-8322-6593-2

– 2 – IEC 60793-1-40:2019 © IEC 2019
CONTENTS
FOREWORD . 5
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 8
4 Calibration requirements . 9
5 Reference test method . 9
6 Apparatus . 9
7 Sampling and specimens . 9
7.1 Specimen length . 9
7.2 Specimen end face . 9
8 Procedure . 9
9 Calculations . 9
9.1 Methods A and B . 9
9.2 Method C . 9
9.3 Method D . 9
10 Results . 9
10.1 Information available with each measurement . 9
10.2 Information available upon request . 10
10.3 Method-specific additional information . 10
11 Specification information . 10
Annex A (normative) Requirements specific to method A – Cut-back . 11
A.1 General . 11
A.2 Apparatus . 11
A.2.1 General apparatus for all fibres. 11
A.2.2 Launch apparatus for all single-mode fibres . 13
A.2.3 Launch apparatus for A1 multimode fibres . 14
A.2.4 Launch apparatus for A2 to A4 multimode fibres . 16
A.2.5 Calibration requirements . 17
A.3 Procedure . 18
A.4 Calculations . 18
Annex B (normative) Requirements specific to method B – Insertion loss . 19
B.1 General . 19
B.2 Apparatus . 19
B.2.1 General set-ups . 19
B.2.2 Apparatus common to method A (cut-back). 19
B.2.3 Additional apparatus specific to method B (insertion-loss) . 19
B.2.4 Calibration requirements . 19
B.3 Procedure . 19
B.4 Calculations . 20
Annex C (normative) Requirements specific to method C – Backscattering . 21
C.1 General . 21
C.2 Apparatus . 21
C.2.1 General . 21
C.2.2 Optical transmitter . 22
C.2.3 Launch conditions . 22

C.2.4 Optical splitter . 22
C.2.5 Optical receiver . 22
C.2.6 Pulse duration and repetition rate . 22
C.2.7 Signal processor . 22
C.2.8 Display . 23
C.2.9 Data interface (optional) . 23
C.2.10 Reflection controller (optional) . 23
C.2.11 Splices and connectors . 23
C.3 Sampling and specimens . 23
C.4 Procedure . 23
C.4.1 General . 23
C.4.2 Further steps for measuring attenuation. 25
C.4.3 Further steps for measuring point discontinuities . 25
C.4.4 Calibration . 27
C.5 Calculations . 27
C.6 Results . 27
Annex D (normative) Requirements specific to method D – Spectral attenuation
modelling . 28
D.1 General . 28
D.2 Apparatus . 28
D.3 Sampling and specimens . 28
D.4 Procedure . 28
D.5 Calculations . 29
D.6 Results . 29
Annex E (informative) Examples of short cable test results on A1 multimode fibres . 31
Bibliography . 33

Figure A.1 – Arrangement of equipment for loss measurement at a specified
wavelength .
...