IEC 60793-1-50:2014

IEC 60793-1-50 ®
Edition 2.0 2014-09
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Optical fibres –
Part 1-50: Measurement methods and test procedures – Damp heat (steady
state) tests
Fibres optiques –
Partie 1-50: Méthodes de mesure et procédures d'essai – Essais de chaleur
humide (état continu)
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IEC 60793-1-50 ®
Edition 2.0 2014-09
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Optical fibres –
Part 1-50: Measurement methods and test procedures – Damp heat (steady

state) tests
Fibres optiques –
Partie 1-50: Méthodes de mesure et procédures d'essai – Essais de chaleur

humide (état continu)
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX H
ICS 33.180.10 ISBN 978-2-8322-1853-2

– 2 – IEC 60793-1-50:2014  IEC 2014
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references . 5
3 Apparatus . 6
3.1 Chamber . 6
3.2 Humidifier . 6
3.3 Other apparatus . 6
4 Sampling and specimens . 6
5 Procedure . 6
5.1 General . 6
5.2 Optical measurements . 6
5.3 Mechanical measurements . 7
5.4 Preconditioning . 7
5.5 Conditioning . 7
5.6 Recovery . 7
6 Pass/fail criteria . 7
7 Results . 7
7.1 Information to be provided with each test . 7
7.2 Information to be available upon request . 8
8 Specification information . 8

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
OPTICAL FIBRES –
Part 1-50: Measurement methods and test procedures –
Damp heat (steady state) tests

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
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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 60793-1-50 has been prepared by subcommittee 86A: Fibres and
cables, of IEC technical committee 86: Fibre optics.
This second edition cancels and replaces the first edition, published in 2001, and constitutes
a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
– harmonization of the content with sectional specifications of relevant fibre types;
– extension of the applicability of the standard to class C single-mode fibres.

– 4 – IEC 60793-1-50:2014  IEC 2014
The text of this standard is based on the following documents:
CDV Report on voting
86A/1526/CDV 86A/1572/RVC
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 60793 series, published under the general title Optical fibres, 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.
OPTICAL FIBRES –
Part 1-50: Measurement methods and test procedures –
Damp heat (steady state) tests

1 Scope
This part of IEC 60793 provides a practical method for evaluating fibre performance in a
defined environment.
The purpose of this standard is to determine the suitability of optical fibre sub-category A1a to
A1d multimode fibres and class B and C single-mode fibres to withstand the environmental
condition of high humidity and high temperature which may occur in actual use, storage
and/or transport. The test is primarily intended to permit the observation of effects of high
humidity at constant temperature over a given period. This procedure is conducted in
accordance with IEC 60068-2-78, Test Cab.
NOTE The applicability of this test to other fibre categories is under study.
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 60068-2-78, Environmental testing – Part 2-78: Tests – Test Cab: Damp heat, steady
state
IEC 60793-1-31, Optical fibres – Part 1-31: Measurement methods and test procedures –
Tensile strength
IEC 60793-1-32, Optical fibres – Part 1-32: Measurement and test procedures – Coating
strippability
IEC 60793-1-33, Optical fibres – Part 1-33: Measurement methods and test procedures –
Stress corrosion susceptibility
IEC 60793-1-40:2001, Optical fibres – Part 1-40: Attenuation measurement methods
IEC 60793-2-10, Optical fibres – Part 2-10: Product specifications – Sectional specification for
category A1 multimode fibres
IEC 60793-2-50, Optical fibres – Part 2-50: Product specifications – Sectional specification for
class B single mode fibres
IEC 60793-2-60, Optical fibres – Part 2-60: Product specifications – Sectional specification for
class C single-mode intraconnection fibres

– 6 – IEC 60793-1-50:2014  IEC 2014
3 Apparatus
3.1 Chamber
The apparatus consists of an environmental chamber in accordance with IEC 60068-2-78,
Test Cab. The chamber shall be capable of housing the specimen and of allowing access for
measurement during conditioning. It shall also be capable of maintaining the specified
temperature and humidity within the specified tolerances. Forced air circulation may be used
to maintain homogeneous conditions. The chamber and accessories shall be constructed and
arranged in such a manner as to avoid condensation dripping on the specimen.
3.2 Humidifier
De-mineralized or de-ionized water is used to obtain the specified humidity. No rust or
corrosion contaminants shall be imposed on the specimen by the test facility. The water
added to the humidifier shall be controlled according to the manufacturer’s instructions.
3.3 Other apparatus
Additional apparatus may be necessary to perform the examinations and measurements (or
as specified in the detail specification).
4 Sampling and specimens
For optical measurements, the length of the specimen shall be at least 1 000 m for fibre sub-
categories A1a to A1d, and at least 2 000 m for fibre class B and C, to allow the required
measurement repeatability. The amount of the specimen outside of the test chamber shall be
minimized, and if it exceeds 10 % of the overall specimen length, this should be reported.
The preparation of the specimen shall have no detrimental effect on the fibre whilst under test
conditions. Unless otherwise defined in the detail specification, it is recommended that the
fibre sample be loosely coiled and dusted with a material such as talcum powder, to allow the
coils to move freely against each other. The specimen may be coiled horizontally or vertically,
with a minimum bend diameter of 150 mm to avoid any macro-bend effects.
A length of the control specimen shall be removed prior to the test to enable the completion of
required mechanical measurements for comparison to measurements made after the test.
This specimen should not be dusted.
5 Procedure
5.1 General
Conduct the procedure in accordance with IEC 60068-2-78, Test Cab, with the temperature,
humidity and exposure time as given below:
Temperature Relative humidity Exposure time
+85 °C 85 % 30 days
5.2 Optical measurements
Attenuation measurement shall be carried out at the wavelength specified in the relevant
specification using either IEC 60793-1-40:2001, Annex B (insertion loss) or IEC 60793-1-
40:2001, Annex C (backscattering) before, during (once the specimen has stabilized at the
specified temperature and relative humidity) and after the test. Attenuation changes shall be
recorded.
Other optical measurements may be required if specified in the relevant product specification
5.3 Mechanical measurements
The fibre coating strip force shall be measured before and after the test, using the method
described in IEC 60793-1-32. The control specimen (see Clause 4) is used to evaluate the
change in strippability.
The tensile strength shall be measured on the aged specimens, according to IEC 60793-1-31.
The stress corrosion susceptibility parameter, dynamic n v
...