IEC 61757-1-1:2016

Fibre optic sensors - Part 1-1: Strain measurement - Strain sensors based on fibre Bragg gratings

IEC 61757-1-1:2016 defines detail specifications for fibre optic sensors using one or more fibre Bragg gratings (FBG) as the sensitive element for strain measurements. Generic specifications for fibre optic sensors are defined in IEC 61757-1:2012. This standard specifies the most important features and characteristics of a fibre optic sensor for strain measurements based on use of an FBG as the sensitive element, and defines the procedures for their determination. Furthermore, it specifies basic performance parameters and characteristics of the corresponding measuring instrument to read out the optical signal from the FBG. This standard refers to the measurement of static and dynamic strain values in a range of frequencies. A blank detail specification is provided in Annex B. Keywords: Bragg gratings (FBG), strain measurement of fibre optic sensors
This publication is to be read in conjunction with IEC 61757-1:2012.

Capteurs à fibres optiques - Partie 1-1: Mesure de déformation - Capteurs de déformation basés sur des réseaux de Bragg à fibres

IEC 61757-1-1:2016 définit des spécifications particulières pour des capteurs à fibres optiques utilisant un ou plusieurs réseaux de Bragg à fibres (FBG: fibre bragg grating) comme élément de détection pour les mesures de déformation. Des spécifications génériques pour les capteurs à fibres optiques sont définies dans l'IEC 61757-1:2012. Cette norme spécifie les caractéristiques les plus importantes d'un capteur à fibres optiques servant à mesurer des déformations en utilisant un réseau de Bragg à fibres comme élément de détection, et elle définit les procédures permettant de déterminer ces caractéristiques. Elle spécifie également les paramètres et les caractéristiques des performances de base de l'appareil utilisé pour mesurer le signal optique provenant du FBG. La présente norme porte sur la mesure des valeurs de déformations statiques et dynamiques sur une plage de fréquences. Une spécification particulière-cadre est fournie à l'Annexe B.
La présente Norme internationale doit être utilisée conjointement avec l'IEC 61757-1:2012.

General Information

• Status: Published
• Publication Date: 24-Feb-2016
• ICS: 33.180.99 - Other fibre optic equipment
• Technical Committee: SC 86C - Fibre optic systems and active devices
• Drafting Committee: WG 2 - TC 86/SC 86C/WG 2
• Current Stage: DELPUB - Deleted Publication
• Start Date: 07-Dec-2018
• Completion Date: 27-Mar-2020

Relations

• Revised: IEC 61757-1-1:2020 - Fibre optic sensors - Part 1-1: Strain measurement - Strain sensors based on fibre Bragg gratings
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC 61757-1-1 ®
Edition 1.0 2016-02
INTERNATIONAL
STANDARD
colour
inside
Fibre optic sensors –
Part 1-1: Strain measurement – Strain sensors based on fibre Bragg gratings

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.

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About the IEC
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International Standards for all electrical, electronic and related technologies.

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IEC 61757-1-1 ®
Edition 1.0 2016-02
INTERNATIONAL
STANDARD
colour
inside
Fibre optic sensors –
Part 1-1: Strain measurement – Strain sensors based on fibre Bragg gratings

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 33.180.99 ISBN 978-2-8322-3188-3

– 2 – IEC 61757-1-1:2016 © IEC 2016

CONTENTS
FOREWORD . 5

INTRODUCTION . 7

1 Scope . 8

2 Normative references. 8

3 Terms and definitions . 9

4 Symbols . 13

5 Structure and characteristics . 14
5.1 Fibre Bragg grating (FBG) . 14
5.2 FBG strain sensor configuration. 18
5.3 Measuring point and installation . 18
5.4 Gauge length . 19
5.5 Strain and reference strain . 19
5.6 Reference wavelength . 19
5.7 Stability behaviour . 20
5.7.1 Drift and creep . 20
5.7.2 Shape stability of the Bragg grating peak . 20
5.7.3 Hysteresis . 20
5.8 Test specimen . 20
5.9 Indication of the measured values . 21
5.10 Zero point related measurement . 21
5.11 Non-zero point related measurement . 21
5.12 Production set . 21
5.13 FBG strain sensor standard type . 21
5.14 FBG strain sensor series . 21
6 Features and characteristics to be reported . 21
6.1 Construction details and geometrical dimensions . 21
6.2 Configuration of the FBG strain sensor . 22
6.3 Temperature and humidity range . 22
6.4 Connecting requirement . 22
7 Features and characteristics to be measured . 22
7.1 Sampling and statistical evaluation . 22
7.1.1 Sampling . 22
7.1.2 Random sampling . 22
7.1.3 Type testing . 22
7.1.4 Series testing . 22
7.1.5 Individual sample testing . 23
7.1.6 Reporting the measuring result . 23
7.1.7 Sample conditioning . 23
7.1.8 Ambient test conditions . 23
7.1.9 Required type of test for individual characteristics . 23
7.2 Bragg wavelength λ . 24
B
7.2.1 General . 24
7.2.2 Measuring procedure . 24
7.2.3 Evaluation . 25
7.2.4 Reporting . 25

7.3 FBG spectral width . 25

7.3.1 Measuring procedure . 25

7.3.2 Evaluation . 25

7.3.3 Reporting . 25

7.4 FBG reflectivity . 25

7.4.1 Measuring procedure . 25

7.4.2 Evaluation . 26

7.4.3 Reporting . 26

7.5 FBG Strain sensitivity . 26

7.5.1 General . 26

7.5.2 Tensile test set-up . 27
7.5.3 Measuring procedure tensile test . 27
7.5.4 Evaluation . 28
7.5.5 Reporting . 28
7.6 Gauge factor k . 28
7.6.1 General . 28
7.6.2 Bending test set-up . 29
7.6.3 Measurement procedure . 31
7.6.4 Evaluation . 32
7.6.5 Reporting . 32
7.7 Maximum strain range at room temperature . 32
7.7.1 General . 32
7.7.2 Test set-up . 32
7.7.3 Measuring procedure . 33
7.7.4 Evaluation . 33
7.7.5 Reporting . 33
7.8 Fatigue behaviour . 34
7.8.1 Test set-up . 34
7.8.2 Measuring procedure . 34
7.8.3 Evaluation . 34
7.8.4 Reporting . 35
7.9 Minimum operating radius of curvature . 35
7.9.1 Measuring procedure . 35
7.9.2 Evaluation . 35
7.9.3 Reporting . 35

7.10 Temperature and humidity ranges . 35
7.10.1 General . 35
7.10.2 Measuring procedure . 36
7.10.3 Evaluation . 36
7.10.4 Reporting . 36
7.11 Other environmental influences . 36
7.12 Temperature-induced strain response . 36
7.12.1 General . 36
7.12.2 Test set-up . 37
7.12.3 Measuring procedure . 38
7.12.4 Evaluation . 38
7.12.5 Reporting . 38
7.13 Proof test and lifetime considerations .
...

IEC 61757-1-1 ®
Edition 1.0 2016-02
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Fibre optic sensors –
Part 1-1: Strain measurement – Strain sensors based on fibre Bragg gratings

Capteurs à fibres optiques –
Partie 1-1: Mesure de déformation – Capteurs de déformation basés sur des
réseaux de Bragg à fibres
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.

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ni utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie

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Switzerland www.iec.ch
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 corrigenda or an amendment might have been published.

IEC Catalogue - webstore.iec.ch/catalogue Electropedia - www.electropedia.org
The stand-alone application for consulting the entire The world's leading online dictionary of electronic and
bibliographical information on IEC International Standards, electrical terms containing 20 000 terms and definitions in
Technical Specifications, Technical Reports and other English and French, with equivalent terms in 16 additional
documents. Available for PC, Mac OS, Android Tablets and languages. Also known as the International Electrotechnical
iPad. Vocabulary (IEV) online.

IEC publications search - www.iec.ch/searchpub IEC Glossary - std.iec.ch/glossary
The advanced search enables to find IEC publications by a 65 000 electrotechnical terminology entries in English and
variety of criteria (reference number, text, technical French extracted from the Terms and Definitions clause of
committee,…). It also gives information on projects, replaced IEC publications issued since 2002. Some entries have been
and withdrawn publications. collected from earlier publications of IEC TC 37, 77, 86 and

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IEC 61757-1-1 ®
Edition 1.0 2016-02
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Fibre optic sensors –
Part 1-1: Strain measurement – Strain sensors based on fibre Bragg gratings

Capteurs à fibres optiques –
Partie 1-1: Mesure de déformation – Capteurs de déformation basés sur des

réseaux de Bragg à fibres
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 33.180.99 ISBN 978-2-8322-5166-9

– 2 – IEC 61757-1-1:2016 © IEC 2016

CONTENTS
FOREWORD . 5

INTRODUCTION . 7

1 Scope . 8

2 Normative references . 8

3 Terms and definitions . 9

4 Symbols . 13

5 Structure and characteristics . 14

5.1 Fibre Bragg grating (FBG) . 14
5.2 FBG strain sensor configuration . 18
5.3 Measuring point and installation . 18
5.4 Gauge length . 19
5.5 Strain and reference strain . 19
5.6 Reference wavelength . 19
5.7 Stability behaviour . 20
5.7.1 Drift and creep . 20
5.7.2 Shape stability of the Bragg grating peak . 20
5.7.3 Hysteresis . 20
5.8 Test specimen . 20
5.9 Indication of the measured values . 21
5.10 Zero point related measurement . 21
5.11 Non-zero point related measurement . 21
5.12 Production set . 21
5.13 FBG strain sensor standard type . 21
5.14 FBG strain sensor series . 21
6 Features and characteristics to be reported . 21
6.1 Construction details and geometrical dimensions . 21
6.2 Configuration of the FBG strain sensor . 22
6.3 Temperature and humidity range . 22
6.4 Connecting requirement . 22
7 Features and characteristics to be measured . 22
7.1 Sampling and statistical evaluation . 22
7.1.1 Sampling . 22

7.1.2 Random sampling . 22
7.1.3 Type testing . 22
7.1.4 Series testing . 22
7.1.5 Individual sample testing . 23
7.1.6 Reporting the measuring result . 23
7.1.7 Sample conditioning . 23
7.1.8 Ambient test conditions . 23
7.1.9 Required type of test for individual characteristics . 23
7.2 Bragg wavelength λ . 24
B
7.2.1 General . 24
7.2.2 Measuring procedure . 24
7.2.3 Evaluation . 25
7.2.4 Reporting . 25
7.3 FBG spectral width. 25

7.3.1 Measuring procedure . 25

7.3.2 Evaluation . 25

7.3.3 Reporting . 25

7.4 FBG reflectivity . 25

7.4.1 Measuring procedure . 25

7.4.2 Evaluation . 26

7.4.3 Reporting . 26

7.5 FBG Strain sensitivity . 26

7.5.1 General . 26

7.5.2 Tensile test set-up . 27

7.5.3 Measuring procedure tensile test . 27
7.5.4 Evaluation . 28
7.5.5 Reporting . 28
7.6 Gauge factor k . 28
7.6.1 General . 28
7.6.2 Bending test set-up . 29
7.6.3 Measurement procedure . 31
7.6.4 Evaluation . 32
7.6.5 Reporting . 32
7.7 Maximum strain
...