SIST EN IEC 61757-3-2:2022
(Main)Fibre optic sensors - Part 3-2: Acoustic sensing and vibration measurement - Distributed sensing (IEC 61757-3-2:2022)
Fibre optic sensors - Part 3-2: Acoustic sensing and vibration measurement - Distributed sensing (IEC 61757-3-2:2022)
This part of IEC 61757 specifies the terminology, characteristic performance parameters,
related test and calculation methods, as well as specific test equipment for interrogation units
used in distributed fibre optic acoustic sensing and vibration measurement systems. This
document refers to the Rayleigh backscatter and phase detection method by phase-sensitive
coherent optical time-domain reflectometry (ϕ-OTDR) only. Quasi-static and low frequency
operation modes are not covered by this document.
Generic specifications for fibre optic sensors are defined in IEC 61757.
Lichtwellenleitersensoren - Teil 3-2: Akustische Sensorik und Schwingungsmessung - Verteilte Sensorik (IEC 61757-3-2:2022)
Capteurs fibroniques – Partie 3-2: Détection acoustique et mesure des vibrations - Détections réparties (IEC 61757-3-2:2022)
IEC 61757-3-2:2022 spécifie la terminologie, les paramètres de performance caractéristiques, les méthodes d’essai et de calcul associées, ainsi que le matériel d’essai spécifique pour les unités d’interrogation utilisées dans les systèmes fibroniques répartis de mesure de vibrations et de détection acoustique. Le présent document se réfère uniquement à la méthode de rétrodiffusion de Rayleigh et de détection de phase par réflectométrie optique cohérente dans le domaine temporel sensible à la phase (ϕ-OTDR). Les modes de fonctionnement quasi statiques et à basses fréquences ne sont pas traités dans le présent document. Les spécifications génériques applicables aux capteurs fibroniques sont définies dans l’IEC 61757.
Optični senzorji - 3-2. del: Akustično zaznavanje in merjenje vibracij - Razpršeno zaznavanje (IEC 61757-3-2:2022)
Ta del standarda IEC 61757 določa terminologijo, značilne parametre delovanja, povezane preskusne in računske metode ter posebno preskusno opremo za zasliševalne enote, ki se uporabljajo pri sistemih z optičnimi vlakni za razpršeno akustično zaznavanje in merjenje vibracij. Ta dokument se navezuje samo na metodo zaznavanja povratnega sipanja in faz po Rayleighu s fazno občutljivo koherentno optično reflektometrijo v časovnem prostoru (ϕ-OTDR). Ta dokument ne obravnava navidezno statičnih in nizkofrekvenčnih načinov delovanja. Splošne specifikacije za optična zaznavala so določene v standardu IEC 61757.
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN IEC 61757-3-2:2022
01-julij-2022
Optični senzorji - 3-2. del: Akustično zaznavanje in merjenje vibracij - Razpršeno
zaznavanje (IEC 61757-3-2:2022)
Fibre optic sensors - Part 3-2: Acoustic sensing and vibration measurement - Distributed
sensing (IEC 61757-3-2:2022)
Lichtwellenleitersensoren - Teil 3-2: Akustische Sensorik und Schwingungsmessung -
Verteilte Sensorik (IEC 61757-3-2:2022)
Capteurs fibroniques – Partie 3-2: Détection acoustique et mesure des vibrations -
Détections réparties (IEC 61757-3-2:2022)
Ta slovenski standard je istoveten z: EN IEC 61757-3-2:2022
ICS:
17.140.01 Akustična merjenja in Acoustic measurements and
blaženje hrupa na splošno noise abatement in general
33.180.99 Druga oprema za optična Other fibre optic equipment
vlakna
SIST EN IEC 61757-3-2:2022 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST EN IEC 61757-3-2:2022
EUROPEAN STANDARD EN IEC 61757-3-2
NORME EUROPÉENNE
EUROPÄISCHE NORM May 2022
ICS 33.180.99
English Version
Fibre optic sensors - Part 3-2: Acoustic sensing and vibration
measurement - Distributed sensing
(IEC 61757-3-2:2022)
Capteurs fibroniques - Partie 3-2: Détection acoustique et Lichtwellenleitersensoren - Teil 3-2: Akustische Sensorik
mesure des vibrations - Détections réparties und Schwingungsmessung - Verteilte Sensorik
(IEC 61757-3-2:2022) (IEC 61757-3-2:2022)
This European Standard was approved by CENELEC on 2022-05-03. 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, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
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Turkey and the United Kingdom.
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
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CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2022 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 61757-3-2:2022 E
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EN IEC 61757-3-2:2022 (E)
European foreword
The text of document 86C/1700/CDV, future edition 1 of IEC 61757-3-2, prepared by SC 86C "Fibre
optic systems and active devices" of IEC/TC 86 "Fibre optics" was submitted to the IEC-CENELEC
parallel vote and approved by CENELEC as EN IEC 61757-3-2:2022.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2023-02-03
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2025-05-03
document have to be withdrawn
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.
Any feedback and questions on this document should be directed to the users’ national committee. A
complete listing of these bodies can be found on the CENELEC website.
Endorsement notice
The text of the International Standard IEC 61757-3-2:2022 was approved by CENELEC as a
European Standard without any modification.
In the official version, for Bibliography, the following note has to be added for the standard indicated:
IEC 60869-1 NOTE Harmonized as EN IEC 60869-1
2
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EN IEC 61757-3-2:2022 (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 61757 2018 Fibre optic sensors - Generic specification EN IEC 61757 2018
IEC 61757-2-2 2016 Fibre optic sensors - Part 2-2: Temperature EN 61757-2-2 2017
measurement - Distributed sensing
3
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SIST EN IEC 61757-3-2:2022
IEC 61757-3-2
®
Edition 1.0 2022-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Fibre optic sensors –
Part 3-2: Acoustic sensing and vibration measurement – Distributed sensing
Capteurs fibroniques –
Partie 3-2: Détection acoustique et mesure des vibrations – Détections réparties
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
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ELECTROTECHNIQUE
INTERNATIONALE
ICS 33.180.99 ISBN 978-2-8322-1093-1
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CONTENTS
FOREWORD . 5
INTRODUCTION . 7
1 Scope . 8
2 Normative references . 8
3 Terms, definitions, abbreviated terms and symbols . 8
3.1 Terms and definitions . 8
3.2 Abbreviated terms . 11
3.3 Symbols . 12
4 Performance parameters of a distributed acoustic sensing system . 13
5 Test apparatuses for performance parameter determination . 13
5.1 Simulated fibre sensor (SFS) . 13
5.2 Fibre stretcher . 14
5.3 Signal generation and amplification instrumentation . 15
5.4 Optical attenuator . 15
5.5 Isolation chamber . 15
6 Test procedures of performance parameters . 16
6.1 General . 16
6.2 Dynamic range . 16
6.2.1 General . 16
6.2.2 Set-up . 16
6.2.3 Stimulus . 16
6.2.4 Data collection and processing . 17
6.2.5 Data reporting. 19
6.3 Frequency response . 19
6.3.1 General . 19
6.3.2 Set-up . 19
6.3.3 Stimulus . 20
6.3.4 Data collection and processing . 20
6.3.5 Data reporting. 21
6.4 Fidelity . 23
6.4.1 General . 23
6.4.2 Set-up . 23
6.4.3 Stimulus . 23
6.4.4 Data collection and processing . 24
6.4.5 Data reporting. 24
6.5 Self-noise . 24
6.5.1 General . 24
6.5.2 Set-up . 24
6.5.3 Stimulus . 25
6.5.4 Data collection and processing . 25
6.5.5 Data reporting. 28
6.6 Spatial resolution . 28
6.6.1 General . 28
6.6.2 Set-up . 29
6.6.3 Stimulus . 29
6.6.4 Data collection and processing . 29
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6.6.5 Data reporting. 30
6.7 Crosstalk . 32
6.7.1 General . 32
6.7.2 Set-up . 32
6.7.3 Stimulus . 32
6.7.4 Data collection and processing . 32
6.7.5 Data reporting. 33
6.8 Loss budget . 33
6.8.1 General . 33
6.8.2 Set-up . 34
6.8.3 Stimulus . 34
6.8.4 Data collection and processing . 34
6.8.5 Data reporting. 34
6.9 Sensor reflection robustness . 35
6.9.1 General . 35
6.9.2 Set-up . 35
6.9.3 Stimulus . 37
6.9.4 Data collection, processing, and reporting . 38
Annex A (informative) Conversion of optical phase measurement to strain . 39
Annex B (normative) Requirements for low uncertainty measurement . 42
B.1 Single tone stimulus testing . 42
B.2 Frequency response testing . 43
Annex C (informative) FFT window functions . 45
C.1 Flat top window used for frequency domain measurements of spectral peaks . 45
C.2 Window functions used for frequency domain noise measurements . 46
Bibliography . 49
Figure 1 – Distributed acoustic sensing system . 9
Figure 2 – Signal parameters relating to time series and their spatial point identification . 12
Figure 3 – Simulated fibre sensor . 14
Figure 4 – Configuration for SFS showing the locations TP , TP , and TP . 14
1 2 3
Figure 5 – Test set-up for dynamic range test . 16
Figure 6 – Example of a strain stimulus signal and recovered phase of IU response
with a limit at 17 s . 18
Figure 7 – Example of a zoom view of strain stimulus signal and recovered phase of IU
response showing a phase jump at 16,98 s . 19
Figure 8 – Test set-up for frequency response test . 20
Figure 9 – Magnitude response showing the 40 stimulus signals all with magnitude . 21
Figure 10 – Interrogator response to test stimulus, scaled in strain units, shown in the
frequency domain . 22
Figure 11 – Interrogator normalized frequency response . 23
Figure 12 – Test set-up for fidelity test . 23
Figure 13 – Test set-up for self-noise . 25
Figure 14 – 2D data field representing the time varying acoustic field as a function of
distance . 26
Figure 15 – System noise floor data processing schematic . 27
Figure 16 – Example plot of self-noise data . 28
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Figure 17 – Test set-up for spatial resolution test. 29
Figure 18 – Spatial sample points to be used for spatial resolution evaluation . 30
Figure 19 – Graphical plotting approach used to determine spatial resolution . 31
Figure 20 – Test set-up for crosstalk measurement . 32
Figure 21 – Highlighted points to be sampled for crosstalk test . 33
Figure 22 – Example plot for crosstalk test results . 33
Figure 23 – Test set-up for loss budget test . 34
Figure 24 – Test configurations for sensor reflection robustness . 36
Figure 25 – Fabrication examples for creating partial reflections . 37
Figure B.1 – Fibre stretcher spatial sample points . 42
Figure B.2 – Frequency domain plot of single tone stimulus . 43
Figure B.3 – Frequency response plot of single tone stimulus . 44
Figure C.1 – Flat-top window and its Fourier transform characteristics [4] . 45
Figure C.2 – Blackman-Harris window and its Fourier transform characteristics [5] . 46
Figure C.3 – Hamming window and its Fourier transform characteristics [6] . 47
Table A.1 – Optical phase and strain relationships . 41
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INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
FIBRE OPTIC SENSORS –
Part 3-2: Acoustic sensing and vibration measurement –
Distributed sensing
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.
IEC 61757-3-2 has been prepared by subcommittee SC 86C: Fibre optic systems and active
devices, of IEC technical committee TC 86: Fibre optics. It is an International Standard.
The text of this International Standard is based on the following documents:
Draft Report on voting
86C/1700/CDV 86C/1719/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.
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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/standardsdev/publications.
A list of all parts in the IEC 61757 series, published under the general title Fibre optic sensors,
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,
• replaced by a revised edition, or
• amended.
IMPORTANT – The "colour inside" logo on the cover page of this document 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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INTRODUCTION
This document is based on SEAFOM Measuring Sensor Performance Document – 02 (SEAFOM
1
MSP-02) [1] . Within the framework of a type C liaison, SEAFOM proposed this document as a
new work item, which was approved by the participating members of IEC SC 86C.
NOTE Except for Figure 1, Figure C.1, Figure C.2, and Figure C.3, all figures in this document were adopted from
SEAFOM MSP-02 either in original or in modified form with permission from SEAFOM.
The IEC 61757 series is published with the following logic: the sub-parts are numbered as
IEC 61757-M-T, where M denotes the measure and T, the technology.
___________
1
Numbers in square brackets refer to the Bibliography.
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FIBRE OPTIC SENSORS –
Part 3-2: Acoustic sensing and vibration measurement –
Distributed sensing
1 Scope
This part of IEC 61757 specifies the terminology, characteristic performance parameters,
related test and calculation methods, as well as specific test equipment for interrogation units
used in distributed fibre optic acoustic sensing and vibration measurement systems. This
document refers to the Rayleigh backscatter and phase detection method by phase-sensitive
coherent optical time-domain reflectometry (ϕ-OTDR) only. Quasi-static and low frequency
operation modes are not covered by this document.
Generic specifications for fibre optic sensors are defined in IEC 61757.
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 61757:2018, Fibre optic sensors – Generic specification
IEC 61757-2-2:2016, Fibre optic sensors – Part 2-2: Temperature measurement – Distributed
sensing
3 Terms, definitions, abbreviated terms and symbols
3.1 Terms and definitions
For the purposes of this document, terms and definitions given in IEC 61757, IEC 61757-2-
2:2016 and the following 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/
3.1.1
distributed fibre optic sensor
fibre optic sensor that provides a spatially resolved measurement of a measurand over an
extended region by means of a continuous sensing element
[SOURCE: IEC 61757:2018, 3.5]
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3.1.2
distributed fibre optic acoustic sensing system
DAS
measurement set-up consisting of a distributed fibre optic sensor connected to an interrogation
unit including processor, data archive, and user interface, which can locally detect acoustic or
vibration induced disturbances (phase change of the backscattering centres) in the fibre
Note 1 to entry: The alternative term fibre optic distributed vibration sensing (DVS) is also used in the industry.
Note 2 to entry: See Figure 1 for a principal DAS set-up. Pulses from a coherent source are sent into the sensor
fibre through an optical circulator, which also taps the coherent Rayleigh backscattering signal to a detector for
subsequent digitization and fast real-time acquisition.
Note 3 to entry: Typically, a DAS detects acoustic or vibration induced disturbances at frequencies below 2 kHz.
Figure 1 – Distributed acoustic sensing system
3.1.3
distance measurement range
maximum distance (specified in length units) from the interrogation unit output connector along
the simulated fibre sensor within which the DAS measures an acoustic signal with specified
measurement performance under defined conditions
[SOURCE: IEC 61757-2-2:2016, 3.2, modified – adapted to acoustic sensing.]
3.1.4
fibre stretcher
device where an external stimulus causes a linearly proportional amount of fibre strain uniformly
across the fibre length attached
Note 1 to entry: Normally the fibre stretcher consists of a piezoelectric cylinder with an electrical stimulus.
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3.1.5
interrogation unit
IU
opto-electronic instrument that is connected to the distributed fibre optic sensor and measures
and records dynamic strain along the fibre
Note 1 to entry: The processor, data archive, and user interface could be combined within the IU or could be a
separate unit connected to the IU. The IU provides processi
...
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