IEC 61300-3-25:2016

IEC 61300-3-25 ®
Edition 3.0 2016-08
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Fibre optic interconnecting devices and passive components – Basic test and
measurement procedures –
Part 3-25: Examinations and measurements – Concentricity of non-angled
ferrules and non-angled ferrules with fibre installed

Dispositifs d'interconnexion et composants passifs fibroniques – Procédures
fondamentales d'essais et de mesures –
Partie 3-25: Examens et mesures – Concentricité des férules sans angle et des
férules sans angle avec fibre montée

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.

Droits de reproduction réservés. Sauf indication contraire, aucune partie de cette publication ne peut être reproduite
ni utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie
et les microfilms, sans l'accord écrit de l'IEC ou du Comité national de l'IEC du pays du demandeur. Si vous avez des
questions sur le copyright de l'IEC ou si vous désirez obtenir des droits supplémentaires sur cette publication, utilisez
les coordonnées ci-après ou contactez le Comité national de l'IEC de votre pays de résidence.

IEC Central Office Tel.: +41 22 919 02 11
3, rue de Varembé Fax: +41 22 919 03 00
CH-1211 Geneva 20 info@iec.ch
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 15 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

CISPR.
IEC Just Published - webstore.iec.ch/justpublished

Stay up to date on all new IEC publications. Just Published IEC Customer Service Centre - webstore.iec.ch/csc
details all new publications released. Available online and If you wish to give us your feedback on this publication or
also once a month by email. need further assistance, please contact the Customer Service
Centre: csc@iec.ch.
A propos de l'IEC
La Commission Electrotechnique Internationale (IEC) est la première organisation mondiale qui élabore et publie des
Normes internationales pour tout ce qui a trait à l'électricité, à l'électronique et aux technologies apparentées.

A propos des publications IEC
Le contenu technique des publications IEC est constamment revu. Veuillez vous assurer que vous possédez l’édition la
plus récente, un corrigendum ou amendement peut avoir été publié.

Catalogue IEC - webstore.iec.ch/catalogue Electropedia - www.electropedia.org
Application autonome pour consulter tous les renseignements
Le premier dictionnaire en ligne de termes électroniques et
bibliographiques sur les Normes internationales,
électriques. Il contient 20 000 termes et définitions en anglais
Spécifications techniques, Rapports techniques et autres
et en français, ainsi que les termes équivalents dans 15
documents de l'IEC. Disponible pour PC, Mac OS, tablettes
langues additionnelles. Egalement appelé Vocabulaire
Android et iPad.
Electrotechnique International (IEV) en ligne.

Recherche de publications IEC - www.iec.ch/searchpub
Glossaire IEC - std.iec.ch/glossary
La recherche avancée permet de trouver des publications IEC 65 000 entrées terminologiques électrotechniques, en anglais
en utilisant différents critères (numéro de référence, texte, et en français, extraites des articles Termes et Définitions des
comité d’études,…). Elle donne aussi des informations sur les publications IEC parues depuis 2002. Plus certaines entrées
projets et les publications remplacées ou retirées. antérieures extraites des publications des CE 37, 77, 86 et

CISPR de l'IEC.
IEC Just Published - webstore.iec.ch/justpublished

Service Clients - webstore.iec.ch/csc
Restez informé sur les nouvelles publications IEC. Just
Published détaille les nouvelles publications parues. Si vous désirez nous donner des commentaires sur cette
Disponible en ligne et aussi une fois par mois par email. publication ou si vous avez des questions contactez-nous:
csc@iec.ch.
IEC 61300-3-25 ®
Edition 3.0 2016-08
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Fibre optic interconnecting devices and passive components – Basic test and

measurement procedures –
Part 3-25: Examinations and measurements – Concentricity of non-angled

ferrules and non-angled ferrules with fibre installed

Dispositifs d'interconnexion et composants passifs fibroniques – Procédures

fondamentales d'essais et de mesures –

Partie 3-25: Examens et mesures – Concentricité des férules sans angle et des

férules sans angle avec fibre montée

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 33.180.20 ISBN 978-2-8322-3618-5

– 2 – IEC 61300-3-25:2016 © IEC 2016
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references. 5
3 General description . 5
3.1 General . 5
3.2 Method A: ferrule surface reference method (reference test method) . 6
3.3 Method B: core centre reference method on a ferrule with fibre installed . 6
4 Apparatus . 6
4.1 Method A . 6
4.2 Method B . 6
5 Procedure . 6
5.1 Method A-1 . 6
5.2 Method A-2 . 7
5.3 Method B . 8
6 Details to be specified . 9
6.1 Method A . 9
6.2 Method B . 9
Bibliography . 10

Figure 1 – Definition of concentricity . 5
Figure 2 – Set-up example for concentricity measurement (method A-1) of ferrules
with fibre installed . 7
Figure 3 – Set-up example for concentricity measurement (method A-2) of bare
ferrules . 8
Figure 4 – Set-up example for concentricity measurement (method B) of ferrules with
fibre installed . 9

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
FIBRE OPTIC INTERCONNECTING DEVICES AND PASSIVE
COMPONENTS – BASIC TEST AND MEASUREMENT PROCEDURES –

Part 3-25: Examinations and measurements – Concentricity of
non-angled ferrules and non-angled ferrules with fibre installed

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 61300-3-25 has been prepared by subcommittee 86B: Fibre optic
interconnecting devices and passive components, of IEC technical committee 86: Fibre optics.
This third edition cancels and replaces the second edition published in 2013 and constitutes a
technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) deletion of method C due to potential damage of ferrule end face by the spindle. Method C
is the ferrule bore reference method for bare ferrules according to IEC 61300-3-25:2013;
b) separation of original method A into method A-1 and method A-2 relating to the two
different types of ferrule (with/without fibre fitted);
c) integration of the content of Annexes A and B into the test procedure.

– 4 – IEC 61300-3-25:2016 © IEC 2016
The text of this standard is based on the following documents:
CDV Report on voting
86B/3900/CDV 86B/3956A/RVC
Full information on the voting for the approval of this document 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.
A list of all parts in the IEC 61300 series, published under the general title, Fibre optic
interconnecting devices and passive components – Basic test and measurement procedures,
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.
FIBRE OPTIC INTERCONNECTING DEVICES AND PASSIVE
COMPONENTS – BASIC TEST AND MEASUREMENT PROCEDURES –

Part 3-25: Examinations and measurements – Concentricity of
non-angled ferrules and non-angled ferrules with fibre installed

1 Scope
This part of IEC 61300 describes the procedure to determine the concentricity of the axis of
the bore in a non-angled ferrule with the axis of the ferrule, and in the case of non-angled
ferrules with fibre installed, to determine the concentricity of the axis of the fibre core with the
axis of the ferrule.
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.
There are no normative references in this document.
3 General description
3.1 General
This procedure describes the measurement of concentricity of ferrules and ferrules with
assembled fibres. Concentricity is defined as twice the distance between the axis of the
ferrule and the axis of the inner diameter of the ferrule (ferrule bore), or in the case of ferrules
with fibre installed, twice the distance between the axis of the ferrule and the axis of the core
of the installed fibre (see Figure 1). When concentricity measurements are made on a ferrule
with fibre installed the results will be affected by the geometry of the fibre, and by the fit of the
fibre in the ferrule inner diameter. Imperfections of the cylindricity and circularity of the
outside diameter of the ferrule will influence the measurement results.
Axis of ferrule
Axis of fibre core or ferrule bore
Concentricity
C
Fibre core
or ferrule bore
Ferrule
IEC
Figure 1 – Definition of concentricity
Two methods of concentricity measurement are described in 3.2 and 3.3.

– 6 – IEC 61300-3-25:2016 © IEC 2016
3.2 Method A: ferrule surface reference method (reference test method)
In Method A, the ferrule is placed in a V-groove or outer diameter (OD) reference mechanism,
and rotated. The displacement of the ferrule inner diameter or fibre core is observed and the
concentricity determined.
3.3 Method B: core centre reference method on a ferrule with fibre installed
Method B uses a roundness measuring instrument to measure concentricity. In this method,
the core axis is fixed at the axis of the measuring instrument, and the concentricity is
determined by measuring, usually with a probe, the displacement of the outer diameter of the
ferrule as the ferrule is rotated.
4 Apparatus
4.1 Method A
The apparatus for method A consists of the following elements:
• V-groove or OD reference mechanism mounted on a micro-manipulator. According to
ISO 2538, the preferred angle for a V-groove is 108°;
• microscope with video camera;
• display;
• light source; a white light is suitable for this procedure;
• signal processor.
4.2 Method B
The apparatus for method B consists of the following elements:
• roundness measuring instrument with microscope including a recorder, X-Y table, chuck
and pickup;
• light source; a white light is suitable for this procedure.
5 Procedure
5.1 Method A-1
The procedure for a ferrule with fibre installed is as follows.
a) Clean the outer surface of the ferrule.
b) Place the ferrule in the V-groove or OD reference mechanism as shown in Figure 2.
c) Illuminate the fibre core from the other end of the fibre.
d) Acquire an image of the illuminated fibre core.
e) Calculate the centre of gravity (COG) with the coordinates x and y of the core-pixels using
the following formula:
x× I(x, y)
 
COGx=
 
∑
I (x,y)≥thresh
total
 
(1)
 y× I(x, y)
COGy=
 
∑
I (x,y)≥thresh
 total 
where
(x,y) is the current pixel location;

I(x,y) is the pixel intensity at this location;
thresh is the threshold (in grey scale value) of the pixel intensity;
total is the number of pixels where pixel intensity (I(x,y)) is equal to or higher than the
threshold.
total= I(x, y)
∑
I (x, y)≥thresh
f) Rotate the ferrule in steps of 60° or less, and repeat steps d) and e), until a complete
rotation is made.
g) Calculate, with the measured positions (σ1 to σn), a circle using the best fit method. The
diameter of the circle equals the maximum displacement C.
Fibre core image at
second position
V-groove or
Fibre core image
OD reference mechanism
before rotation
Microscope
σ
σ
σ
σ
n
Fibre
σ
Ferrule 4
White light
σ
C
Video camera
Fibre core image after rotation (360°)
Signal processor
Display
IEC
Key
σn centre of the fibre core at each position
C maximum displacement of the fibre core image
Figure 2 – Set-up example for concentricity measurement (method A-1)
of ferrules with fibre installed
5.2 Method A-2
The procedure for bare ferrules is as follows.
a) Clean the ferrule bore thoroughly to assure it is free of dirt, burrs or other obstructions.
b) Place the ferrule in the V-groove or OD reference mechanism as shown in Figure 3.
c) Illuminate the bore of the ferrule.
d) Acquire an image of the illuminated ferrule bore.
e) Using high-pass filtering, identify the pixels lying on the edge of the ferrule bore. Find the
centre-coordinates of the bore by calculating the least-square fit of a circle to the edge
pixels. An iterative process shall be used in order to remove all pixels which do not lie
perfectly on the circle.
f) Rotate the ferrule in steps of 60° or less, and repeat steps d) and e), until a complete
rotation is made.
g) Calculate, with the measured positions (σ1 to σn), a circle using the best fit method. The
diameter of the circle equals the maximum displacement C.

– 8 – IEC 61300-3-25:2016 © IEC 2016
Ferrule bore image
V-groove or at second position
Ferrule bore image
OD reference mechanism
before rotation
Microscope
σ
σ
σ
σ
n
σ
White light Ferrule
σ
C
Video camera
Ferrule bore image after rotation (360°)

Signal processor
Display
IEC
Key
...