EN 61280-4-2:2014

Fibre-optic communication subsystem test procedures - Part 4-2: Installed cable plant - Single-mode attenuation and optical return loss measurement

IEC 61280-4-2: 2014 is applicable to the measurement of attenuation and optical return loss of installed optical fibre cable plant using single-mode fibre. This cable plant can include single-mode optical fibres, connectors, adapters, splices and other passive devices. The cabling may be installed in a variety of environments including residential, commercial, industrial and data centre premises, as well as outside plant environments. This standard may be applied to all single-mode fibre types including those designated by IEC 60793-2-50 as Class B fibres.The principles of this standard may be applied to cable plants containing branching devices (splitters) and at specific wavelength ranges in situations where passive wavelength selective components are deployed, such as WDMs, CWDM and DWDM devices. This standard is not intended to apply to cable plant that includes active devices such as fibre amplifiers or dynamic channel equalizers. This second edition cancels and replaces the first edition, published in 1999, and constitutes a technical revision. The main changes with respect to the previous edition are listed below: revision of optical time-domain reflectometer (OTDR) measurements; addition of optical return loss (ORL) measurements; addition of informative annexes on measurement uncertainties, OTDR configuration, test cord attenuation verification and spectral attenuation measurement. Keywords: measurement of attenuation and optical return loss of installed optical fibre cable plant using single-mode fibre

Prüfverfahren für Lichtwellenleiter-Kommunikationsuntersysteme - Teil 4-2: Installierte Kabelanlagen - Einmoden-Dämpfungs- und optische Rückflussdämpfungsmessung

Procédures d’essai des sous-systèmes de télécommunication à fibres optiques - Partie 4-2: Installations câblées - Mesure de l'affaiblissement de réflexion optique et de l'affaiblissement des fibres unimodales

IEC 61280-4-2: 2014 s'applique à la mesure de l'affaiblissement et de l'affaiblissement de réflexion optique d'un câblage en fibre optique installé en usine utilisant des fibres unimodales. Ce câblage installé peut inclure des fibres optiques unimodales, des connecteurs, des adaptateurs, des épissures et d'autres dispositifs passifs. Le câblage peut être installé dans différents environnements tels que des bâtiments résidentiels, commerciaux, industriels et des centres de traitement de données, mais aussi dans des environnements extérieurs. La présente norme peut être appliquée à tous les types de fibres unimodales y compris celles désignées comme des fibres de Classe B par l'IEC 60793-2-50. Les principes de la présente norme peuvent s'appliquer aux câblages installés contenant des dispositifs de commutation (répartiteurs) et sur des plages de longueurs d'onde spécifiques, dans des situations dans lesquelles sont déployés des composants passifs sélectifs en longueurs d'onde , par exemple des dispositifs WDM, CWDM et DWDM. La présente norme n'est pas destinée à s'appliquer à des câblages installés qui incluent des dispositifs actifs tels que des amplificateurs à fibres ou des égaliseurs de canaux de transmission dynamiques. Cette deuxième édition annule et remplace la première édition parue en 1999, dont elle constitue une révision technique. Les principales modifications portant sur cette précédente édition sont les suivantes: révision des mesures de réflectométrie optique dans le domaine temporel (OTDR); ajout des mesures de l'affaiblissement de réflexion optique (ORL); ajout d'annexes informatives sur les incertitudes de mesure, la configuration de l'OTDR, la vérification de l'affaiblissement des cordons d'essai et la mesure de l'affaiblissement spectral. Mots clés : mesure de l'affaiblissement et de l'affaiblissement de réflexion optique d'un câblage en fibre optique installé en usine utilisant des fibres unimodales

Postopki za preskušanje optičnih komunikacijskih podsistemov - 4-2. del: Kabelska inštalacija - Meritve slabljenja v enorodnih vlaknih in optičnih povratnih izgub (IEC 61280-4-2:2014)

Ta del standarda IEC 61280 se porablja za meritve slabljenja in optičnih povratnih izgub kabelskih inštalacij optičnih vlaken z enorodnimi vlakni. Ta kabelska inštalacija lahko vključuje enorodna optična vlakna, konektorje, vmesnike, spojnice in druge pasivne naprave. Okablenje je mogoče inštalirati v različnih okoljih, vključno z domačimi, komercialnimi, industrijskimi prostori in prostori podatkovnih centrov, in tudi v okoljih dobaviteljev. Ta standard se lahko uporablja za vse vrste enorodnih vlaken, vključno s tistimi, določenimi v standardu IEC 60793-2-50 kot vlakna razreda B.
Principi tega standarda se lahko uporabljajo za kabelske inštalacije z razvejilnimi elementi (delilniki) in v določenem razponu valovne dolžine v situacijah, kjer so razmeščene pasivne valovnodolžinske selektivne komponente, kot so naprave WDM, CWDM in DWDM.
Ta standard ni namenjen za uporabo pri kabelski inštalaciji z aktivnimi napravami, kot so ojačevalniki optičnih vlaken ali dinamični kanalni stabilizatorji.

General Information

• Status: Published
• Publication Date: 18-Sep-2014
• Withdrawal Date: 31-Jul-2017
• ICS: 33.180.01 - Fibre optic systems in general
• Technical Committee: CLC/SR 86C - Fibre optic systems and active devices
• Drafting Committee: IEC/SC 86C - IEC_SC_86C
• Current Stage: 6060 - Document made available - Publishing
• Start Date: 19-Sep-2014
• Completion Date: 19-Sep-2014
• Ref Project: SIST EN 61280-4-2:2014 - Fibre-optic communication subsystem test procedures - Part 4-2: Installed cable plant- Single-mode attenuation and optical return loss measurement

Relations

• Replaces: EN 61280-4-2:1999 - Fibre optic communication subsystem basic test procedures - Part 4-2: Fibre optic cable plant - Single-mode fibre optic cable plant attenuation
• Effective Date: 28-Jan-2023
• Replaced By: EN IEC 61280-4-2:2024 - Fibre-optic communication subsystem test procedures - Part 4-2: Installed cabling plant - Single-mode attenuation and optical return loss measurements
• Effective Date: 23-Jan-2023

EN 61280-4-2:2014 - Fibre‑optic communication subsystem test procedures (Single‑mode attenuation & ORL)

Overview

EN 61280-4-2:2014 (IEC 61280-4-2:2014) defines test procedures for the measurement of attenuation and optical return loss of installed optical fibre cable plant using single‑mode fibre. It covers installed cabling that may include single‑mode fibres (including IEC 60793‑2‑50 Class B types), connectors, adapters, splices and other passive devices across environments such as residential, commercial, industrial, data centres and outside plant. The standard applies to passive cable plants and to situations with passive wavelength‑selective components (WDM, CWDM, DWDM) but excludes cable plants containing active devices (e.g., fibre amplifiers).

This second edition updates OTDR measurement guidance, adds optical return loss (ORL) measurements, and includes informative annexes on measurement uncertainties, OTDR configuration, test cord attenuation verification and spectral attenuation measurement.

Key technical topics and requirements

• Measurement scope: Attenuation and optical return loss (ORL) for installed single‑mode cable plant including passive components.
• Test methods: Multiple reference and test procedures are specified (e.g., one‑cord, two‑cord, three‑cord reference methods), OTDR‑based measurements and continuous‑wave ORL methods (Method A).
• Apparatus & configuration: Requirements for light sources, power meters, OTDRs, launch/tail/substitution cords, ORL test sets, adapters and connector inspection/cleaning equipment.
• Uncertainty and verification: Guidance on measurement uncertainties, test cord care and verification, and procedures to reduce errors (reflections, mode‑field variations, spectral characteristics).
• Documentation & calculations: Defined calculation methods for attenuation, OTDR trace interpretation, ORL results and required test reporting details.
• Applicability: Includes notes on using the methods with branching devices (splitters) and wavelength‑selective passive components.

Practical applications - who uses this standard

• Network installers and contractors - acceptance testing and handover verification of installed single‑mode links.
• Telecommunications service providers & network operators - commissioning, troubleshooting and SLA verification for fibre links.
• Data centre and enterprise cabling teams - validation of backbone and inter‑rack single‑mode cabling.
• Test laboratories and certifiers - standardized procedures for formal measurement, reporting and conformity assessment.
• Equipment manufacturers - aligning test fixtures, adapters and test equipment to recognized measurement methods.

Related standards (normative references)

• IEC/EN 60793‑2‑50 (single‑mode fibre specifications)
• IEC 61300 series (connector inspection, return loss tests)
• IEC 61746‑1 (OTDR calibration)
• IEC 61280‑1‑3 and IEC 61315 (power meter calibration)
• IEC 61755 series (reflectance test methods)

SIST EN 61280‑4‑2:2014 is essential where reliable, repeatable measurement of attenuation and optical return loss for installed single‑mode fibre cable plant is required - ensuring interoperability, performance verification and consistent test reporting.

Standards Content (Sample)

SLOVENSKI STANDARD
01-december-2014
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SIST EN 61280-4-2:2001
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.DEHOVNDLQãWDODFLMD0HULWYHVODEOMHQMDYHQRURGQLKYODNQLKLQRSWLþQLKSRYUDWQLK
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Fibre-optic communication subsystem test procedures - Part 4-2: Installed cable plant-
Single-mode attenuation and optical return loss measurement
Procédures d’essai des sous-systèmes de télécommunication à fibres optiques - Partie 4
-2: Installations câblées - Mesure de l'affaiblissement de réflexion optique et de
l'affaiblissement des fibres unimodales
Ta slovenski standard je istoveten z: EN 61280-4-2:2014
ICS:
33.180.01 6LVWHPL]RSWLþQLPLYODNQLQD Fibre optic systems in
VSORãQR general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN 61280-4-2

NORME EUROPÉENNE
EUROPÄISCHE NORM
September 2014
ICS 33.180.01 Supersedes EN 61280-4-2:1999
English Version
Fibre-optic communication subsystem test procedures - Part 4-2:
Installed cable plant - Single-mode attenuation and optical return
loss measurement
(IEC 61280-4-2:2014)
Procédures d'essai des sous-systèmes de Prüfverfahren für Lichtwellenleiter-
télécommunication à fibres optiques - Partie 4-2: Kommunikationsuntersysteme - Teil 4-2: Installierte
Installations câblées - Mesure de l'affaiblissement de Kabelanlagen - Einmoden-Dämpfungs- und optische
réflexion optique et de l'affaiblissement des fibres Rückflussdämpfungsmessung
unimodales (IEC 61280-4-2:2014)
(CEI 61280-4-2:2014)
This European Standard was approved by CENELEC on 2014-08-01. 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, 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: Avenue Marnix 17, B-1000 Brussels
© 2014 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN 61280-4-2:2014 E
Foreword
The text of document 86C/1238/FDIS, future edition 2 of IEC 61280-4-2, 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 61280-4-2:2014.
The following dates are fixed:
• latest date by which the document has (dop) 2015-05-01
to be implemented at national level by
publication of an identical national
standard or by endorsement
(dow) 2017-08-01
• latest date by which the national
standards conflicting with the
document have to be withdrawn
This document supersedes EN 61280-4-2:1999.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC [and/or CEN] shall not be held responsible for identifying any or all such patent
rights.
Endorsement notice
The text of the International Standard IEC 61280-4-2:2014 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 60793-2 NOTE Harmonized as EN 60793-2.
IEC 61280-1-3 NOTE Harmonized as EN 61280-1-3.
IEC 61753-1 NOTE Harmonized as EN 61753-1.
IEC 61755-2-1 NOTE Harmonized as EN 61755-2-1.
IEC 61755-2-2 NOTE Harmonized as EN 61755-2-2.
1)
IEC 61755-2-4 NOTE Harmonized as EN 61755-2-4 .
1)
IEC 61755-2-5 NOTE Harmonized as EN 61755-2-5 .

1)
To be published.
- 3 - EN 61280-4-2:2014
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
NOTE 1 When 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 60793-2-50 -  Optical fibres -- Part 2-50: Product EN 60793-2-50 -
specifications - Sectional specification for
class B single-mode fibres
IEC 60825-2 -  Safety of laser products -- Part 2: Safety of EN 60825-2 -
optical fibre communication systems (OFCS)
IEC 60874-14-2 -  Connectors for optical fibres and cables - - -
Part 14-2: Detail specification for fibre optic
connector type SC-PC tuned terminated to
single-mode fibre type B1
IEC 61300-3-6 -  Fibre optic interconnecting devices and EN 61300-3-6 -
passive components - Basic test and
measurement procedures -- Part 3-6:
Examinations and measurements - Return
loss
IEC 61300-3-35 -  Fibre optic interconnecting devices and EN 61300-3-35 -
passive components - Basic test and
measurement procedures -- Part 3-35:
Examinations and measurements - Visual
inspection of fibre optic connectors and
fibre-stub transceivers
IEC 61315 -  Calibration of fibre-optic power meters EN 61315 -
IEC 61746-1 2009 Calibration of Optical Time-Domain EN 61746-1 2011
Reflectometers (OTDR) -- Part 1: OTDR for
single-mode fibres
IEC/TR 62627-01 -  Fibre optic interconnecting devices and - -
passive components - Part 01: Fibre optic
connector cleaning methods
IEC 61280-4-2 ®
Edition 2.0 2014-06
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Fibre-optic communication subsystem test procedures –

Part 4-2: Installed cable plant – Single-mode attenuation and optical return

loss measurement
Procédures d’essai des sous-systèmes de télécommunication à

fibres optiques –
Partie 4-2: Installations câblées – Mesure de l'affaiblissement de réflexion

optique et de l'affaiblissement des fibres unimodales

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX XC
ICS 33.180.01 ISBN 978-2-8322-1665-1

– 2 – IEC 61280-4-2:2014  IEC 2014
CONTENTS
FOREWORD . 7
INTRODUCTION . 9
1 Scope . 10
2 Normative references . 10
3 Terms, definitions, graphical symbols and abbreviations . 11
3.1 Terms and definitions . 11
3.2 Graphical symbols . 13
3.3 Abbreviations . 14
4 Measurement methods . 15
4.1 General . 15
4.2 Cabling configurations and applicable test methods . 16
4.2.1 Cabling configurations and applicable test methods for attenuation
measurements . 16
4.2.2 Cabling configurations and applicable test methods for optical return

loss measurements . 18
4.3 Overview of uncertainties . 18
4.3.1 General . 18
4.3.2 Test cords . 18
4.3.3 Reflections from other interfaces . 18
4.3.4 Optical source . 18
4.3.5 Output power reference . 19
4.3.6 Received power reference . 19
4.3.7 Mode field diameter variation . 19
4.3.8 Bi-directional measurements . 19
5 Apparatus . 19
5.1 General . 19
5.2 Light source . 19
5.2.1 Stability . 19
5.2.2 Spectral characteristics . 20
5.2.3 Launch cord . 20
5.3 Receive or tail cord . 20
5.4 Substitution cord . 21
5.5 Power meter – LSPM methods only. 21
5.6 OTDR apparatus . 21
5.7 Return loss test set . 22
5.8 Connector end-face cleaning and inspection equipment . 22
5.9 Adapters . 22
6 Procedures . 22
6.1 General . 22
6.2 Common procedures . 23
6.2.1 Care of the test cords . 23
6.2.2 Make reference measurements (LSPM and OCWR methods only) . 23
6.2.3 Inspect and clean the ends of the fibres in the cabling . 23
6.2.4 Make the measurements . 23
6.2.5 Make the calculations . 23
6.3 Calibration . 23

IEC 61280-4-2:2014  IEC 2014 – 3 –
6.4 Safety . 24
7 Calculations . 24
8 Documentation . 24
8.1 Information for each test . 24
8.2 Information to be made available . 24
Annex A (normative) One-cord reference method . 25
A.1 Applicability of test method . 25
A.2 Apparatus . 25
A.3 Procedure . 25
A.4 Calculation . 26
A.5 Components of reported attenuation . 26
Annex B (normative) Three-cord reference method . 27
B.1 Applicability of test method . 27
B.2 Apparatus . 27
B.3 Procedure . 27
B.4 Calculations . 28
B.5 Components of reported attenuation . 28
Annex C (normative) Two-cord reference method . 29
C.1 Applicability of test method . 29
C.2 Apparatus . 29
C.3 Procedure . 29
C.4 Calculations . 31
C.5 Components of reported attenuation . 31
Annex D (normative) Optical time domain reflectometer . 32
D.1 Applicability of test method . 32
D.2 Apparatus . 32
D.2.1 General . 32
D.2.2 OTDR . 32
D.2.3 Test cords . 32
D.3 Procedure (test method) . 33
D.4 Calculation of attenuation . 34
D.4.1 General . 34
D.4.2 Connection location . 34
D.4.3 Definition of the power levels F and F . 35
1 2
D.4.4 Alternative calculation. 36
D.5 Calculation of optical return loss . 37
D.6 Calculation of reflectance for discrete components . 39
D.7 OTDR uncertainties . 40
Annex E (normative) Continuous wave optical return loss measurement – Method A . 41
E.1 Applicability of test method . 41
E.2 Apparatus . 41
E.2.1 General . 41
E.2.2 Light source . 41
E.2.3 Branching device or coupler . 41
E.2.4 Power meters . 42
E.2.5 Connector interface . 42
E.2.6 Low reflection termination . 42
E.3 Procedure . 42

– 4 – IEC 61280-4-2:2014  IEC 2014
E.3.1 Test set characterization. 42
E.3.2 Measurement procedure . 44
E.3.3 Calculations . 44
E.3.4 Measurement uncertainty. 45
Annex F (normative) Continuous wave optical return loss measurement – Method B. 46
F.1 Applicability of test method . 46
F.2 Apparatus . 46
F.2.1 General requirements . 46
F.2.2 Known reflectance termination . 46
F.3 Procedure . 46
F.3.1 Set-up characterization . 46
F.3.2 Measurement procedure . 47
F.3.3 Calculation . 48
F.3.4 Measurement uncertainty. 48
Annex G (informative) Measurement uncertainty examples . 49
G.1 Reduction of uncertainty by using reference grade terminations and related
issues . 49
G.1.1 Motivations for using reference grade terminations on test cords . 49
G.1.2 Adjusting acceptance limits to allow for different expected losses when
using reference grade and standard grade connectors . 49
G.2 Estimation of the measurement uncertainties . 51
G.2.1 Measurement uncertainty. 51
G.2.2 Uncertainty due to the instrument . 51
G.2.3 Uncertainty due to the source . 51
G.2.4 Uncertainty due to the device under test . 52
G.2.5 Example of uncertainty accumulation using a single power meter . 53
G.2.6 Example of uncertainty accumulation using two power meters . 54
Annex H (informative) OTDR configuration information . 55
H.1 Introductory remarks . 55
H.2 Fundamental parameters that define the operational capability of an OTDR . 56
H.2.1 Dynamic range . 56
H.2.2 Pulse width . 56
H.2.3 Averaging time . 56
H.2.4 Dead zone . 56
H.3 Other parameters . 56
H.3.1 Index of refraction . 56
H.3.2 Measurement range . 57
H.3.3 Distance sampling . 57
H.4 Other measurement configurations . 57
H.4.1 General . 57
H.4.2 Macro bend attenuation measurement . 57
H.4.3 Splice attenuation measurement . 58
H.4.4 Measurement with high reflection connectors or short length cabling . 58
H.4.5 Ghost . 60
H.5 More on the measurement method . 61
H.6 Bidirectional measurement . 62
H.7 OTDR bi-directional trace analysis . 63
H.8 Non recommended practices . 64
H.8.1 Measurement without tail cord . 64

IEC 61280-4-2:2014  IEC 2014 – 5 –
H.8.2 Cursor measurement . 64
Annex I (informative) Test cord attenuation verification . 65
I.1 Introductory remarks . 65
I.2 Apparatus . 65
I.3 Procedure . 65
I.3.1 General . 65
I.3.2 Test cord verification for the one-cord and two-cord reference test
methods when using non-pinned/unpinned and non-plug/socket style
connectors . 66
I.3.3 Test cord verification for the one-cord and two-cord reference test
methods using pinned/unpinned or plug/socket style connectors . 67
I.3.4 Test cord verification for the three-cord reference test method using
non-pinned/unpinned and non-plug/socket style connectors. 68
I.3.5 Test cord verification for the three-cord reference test method using
pinned/unpinned or plug/socket style connectors . 70
Annex J (informative) Spectral attenuation measurement . 72
J.1 Applicability of test method . 72
J.2 Apparatus . 72
J.2.1 Broadband light source . 72
J.2.2 Optical spectrum analyser . 72
J.3 Procedure . 72
J.3.1 Reference scan . 72
J.3.2 Measurement scan . 73
J.4 Calculations . 73
Bibliography . 74

Figure 1 – Connector symbols . 13
Figure 2 – Symbol for cabling under test . 14
Figure 3 – Configuration A – Start and end of measured losses in reference test
method . 16
Figure 4 – Configuration B – Start and end of measured losses in reference test
method . 17
Figure 5 – Configuration C – Start and end of measured losses in reference test
method . 17
Figure 6 – Typical OTDR schematic . 21
Figure 7 – Return loss test set illustration . 22
Figure A.1 − One-cord reference measurement . 26
Figure A.2− One-cord test measurement . 26
Figure B.1 − Three-cord reference measurement . 27
Figure B.2 − Three-cord test measurement . 28
Figure C.1 − Two-cord reference measurement. 30
Figure C.2 − Two-cord test measurement . 30
Figure C.3 – Two-cord test measurement for plug-socket style connectors . 30
Figure D.1 − Test measurement for method D . 34
Figure D.2 − Location of the cabling under test ports . 35
Figure D.3 − Graphic construction of F and F . 36
1 2
Figure D.4 − Graphic construction of F , F , F and F . 37
1 11 21 2
– 6 – IEC 61280-4-2:2014  IEC 2014
Figure D.5 − Graphic representation of OTDR ORL measurement . 38
Figure D.6 − Graphic representation of reflectance measurement . 39
Figure E.1 – Return loss test set illustration . 41
Figure E.2 – Measurement of the system internal attenuation P . 43
ref2
Figure E.3 – Measurement of the system internal attenuation P . 43
ref1
Figure E.4 – Measurement of the system reflected power P . 43
rs
Figure E.5 – Measurement of the input power P . 44
in
Figure E.6 – Measurement of the reflected power . 44
Figure F.1 – Return loss test set illustration . 46
Figure F.2 – Measurement of P with reflections suppressed . 47
rs
Figure F.3 – Measurement of P with reference reflector . 47
ref
Figure F.4 – Measurement of the system reflected power P . 47
rs
Figure F.5 – Measurement of the reflected power . 48
Figure H.1 − Splice and macro bend attenuation measurement . 58
Figure H.2 − Attenuation measurement with high reflection connectors . 59
Figure H.3 − Attenuation measurement of a short length cabling . 60
Figure H.4 − OTDR trace with ghost . 61
Figure H.5 − Cursor positioning. 62
Figure H.6 – Bidirectional OTDR trace display . 63
Figure H.7 – Bi-directional OTDR trace loss analysis . 63
Figure I.1 − Obtaining reference power level P . 66
Figure I.2 − Obtaining power level P . 67
Figure I.3 − Obtaining reference power level P . 67
Figure I.4 − Obtaining power level P . 67
Figure I.5 − Obtaining reference power level P . 68
Figure I.6 − Obtaining power level . 68
Figure I.7 − Obtaining reference power level P . 69
Figure I.8 − Obtaining power level P . 69
Figure I.9 − Obtaining power level P . 70
Figure I.10 − Obtaining reference power level P . 70
Figure I.11 − Obtaining power level P . 71
Figure J.1 − Result of spectral attenuation measurement . 73

Table 1 – Cabling configurations . 16
Table 2 – Test methods and configurations . 17
Table D.1 – Typical launch and tail cord lengths . 33
(see NOTE 1)
Table G.1 – Expected loss for examples . 49
Table G.2 – Example of uncertainty accumulation using a single power meter . 53
Table G.3 – Example of uncertainty accumulation using two power meters . 54
Table H.1 – Example of effective group index of refraction values . 57

IEC 61280-4-2:2014  IEC 2014 – 7 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
FIBRE-OPTIC COMMUNICATION SUBSYSTEM TEST PROCEDURES –

Part 4-2: Installed cable plant –
Single-mode attenuation and optical return loss measurement

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,
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International Standard IEC 61280-4-2 has been prepared by subcommittee SC86C: Fibre
optic systems and active devices, of IEC technical committee 86: Fibre optics.
This second edition cancels and replaces the first edition, published in 1999, and constitutes
a technical revision.
The main changes with respect to the previous edition are listed below:
– revision of optical time-domain reflectometer (OTDR) measurements;
– addition of optical return loss (ORL) measurements;
– addition of informative annexes on measurement uncertainties, OTDR configuration, test
cord attenuation verification and spectral attenuation measurement.

– 8 – IEC 61280-4-2:2014  IEC 2014
The text of this standard is based on the following documents:
FDIS Report on voting
86C/1238/FDIS 86C/1261/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts in the IEC 61280 series, published under the general title Fibre-optic
communication subsystem test procedures, can be found on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication 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.
IEC 61280-4-2:2014  IEC 2014 – 9 –
INTRODUCTION
This second edition of IEC 61280-4-2 for testing single-mode cable plant follows on from the
second edition of IEC 61280-4-1, dealing with multimode cable plants.
Cabling design standards such as ISO/IEC 11801 for commercial premises, ISO/IEC 24702
for industrial premises, ISO/IEC 24764 for data centres and ISO/IEC 15018 for residential
cabling contain specifications for this type of cabling. These standards support cabling
lengths of up to 2 km for commercial premises and data centres and up to 10 km for industrial
premises. ISO/IEC 14763-3, which supports these design standards, makes reference to the
test methods of this standard.
Various recommendations from ITU-T have requirements for longer distance applications
including short haul (40 km), long haul (80 km) and ultra long haul (160 km). The testing of
cable plant for these is covered in ITU-T Recommendation G.650.3, which makes reference to
the test methods of this standard.

– 10 – IEC 61280-4-2:2014  IEC 2014
FIBRE-OPTIC COMMUNICATION SUBSYSTEM TEST PROCEDURES –

Part 4-2: Installed cable plant –
Single-mode attenuation and optical return loss measurement

1 Scope
This part of IEC 61280 is applicable to the measurement of attenuation and optical return loss
of installed optical fibre cable plant using single-mode fibre. This cable plant can include
single-mode optical fibres, connectors, adapters, splices and other passive devices. The
cabling may be installed in a variety of environments including residential, commercial,
industrial and data centre premises, as well as outside plant environments.
This standard may be applied to all single-mode fibre types including those designated by
IEC 60793-2-50 as Class B fibres.
The principles of this standard may be applied to cable plants containing branching devices
(splitters) and at specific wavelength ranges in situations where passive wavelength selective
components are deployed, such as WDMs, CWDM and DWDM devices.
This standard is not intended to apply to cable plant that includes active devices such as fibre
amplifiers or dynamic channel equalizers.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and
are indispensable for its application. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 60793-2-50, Optical fibres – Part 2-50: Product specifications – Sectional specification for
class B single-mode fibres
IEC 60825-2, Safety of laser products – Part 2: Safety of optical fibre communication systems
(OFCS)
IEC 60874-14-2, Connectors for optical fibres and cables – Part 14-2: Detail specification for
fibre optic connector type SC-PC tuned terminated to single-mode fibre type B1
IEC 61300-3-6, Fibre optic interconnecting devices and passive components – Basic test and
measurement procedures – Part 3-6: Examinations and measurements – Return loss
IEC 61300-3-35, Fibre optic interconnecting devices and passive components − Basic test
and measurement procedures − Part 3-35: Examinations and measurements − Fibre optic
cylindrical connector endface visual inspection
IEC 61315, Calibration of fibre-optic power meters
IEC 61746-1:2009, Calibration of optical time-domain reflectometers (OTDR) – Part 1: OTDR
for single-mode fibres
IEC 61280-4-2:2014  IEC 2014 – 11 –
IEC TR 62627-01, Fibre optic interconnecting devices and passive components – Fibre optic
connector cleaning methods
3 Terms, definitions, graphical symbols and abbreviations
For the purposes o
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