IEC 60794-1-212:2024

IEC 60794-1-212 ®
Edition 1.0 2024-04
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Optical fibre cables –
Part 1-212: Generic specification – Basic optical cable test procedures –
Environmental test methods – Temperature cycling with cable elements fixed at
both ends, Method F12
Câbles à fibres optiques –
Partie 1-212: Spécification générique – Procédures fondamentales d’essais des
câbles optiques – Méthodes d’essais d’environnement – Cycle de température
avec éléments de câble fixés aux deux extrémités, Méthode F12
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IEC 60794-1-212 ®
Edition 1.0 2024-04
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Optical fibre cables –
Part 1-212: Generic specification – Basic optical cable test procedures –

Environmental test methods – Temperature cycling with cable elements fixed at

both ends, Method F12
Câbles à fibres optiques –
Partie 1-212: Spécification générique – Procédures fondamentales d’essais des

câbles optiques – Méthodes d’essais d’environnement – Cycle de température

avec éléments de câble fixés aux deux extrémités, Méthode F12

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 33.180.10  ISBN 978-2-8322-8677-7

– 2 – IEC 60794-1-212:2024 © IEC 2024
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Method F12 – Temperature cycling with cable elements fixed at both ends. 7
4.1 Sample . 7
4.2 Apparatus . 7
4.3 Procedure . 7
4.3.1 Preparation of cable sample and DUT. 7
4.3.2 Preparation of test . 7
4.3.3 Preconditioning . 8
4.3.4 Temperature cycling . 8
4.3.5 Requirements . 10
4.4 Details to be specified . 10
4.5 Details to be reported . 10
Bibliography . 11

Figure 1 – Preparation of the cable sample, DUT and test set-up . 8
Figure 2 – Cycle procedure . 10

Table 1 – Minimum soak time t . 9
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
OPTICAL FIBRE CABLES –
Part 1-212: Generic specification – Basic optical cable test procedures –
Environmental test methods – Temperature cycling with cable elements
fixed at both ends, method F12

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
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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) IEC draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). IEC takes no position concerning the evidence, validity or applicability of any claimed patent rights in
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the latest information, which may be obtained from the patent database available at https://patents.iec.ch. IEC
shall not be held responsible for identifying any or all such patent rights.
IEC 60794-1-212 has been prepared by subcommittee 86A: Fibres and cables, of IEC technical
committee 86: Fibre optics. It is an International Standard.
This document partially cancels and replaces IEC 60794-1-22:2017. This edition constitutes a
technical revision.
This edition includes the following significant technical changes with respect to
IEC 60794-1-22:2017:
a) the description of the test method has been changed to “with cable elements fixed at both
ends”;
b) subclauses have been added to the procedure clause;

– 4 – IEC 60794-1-212:2024 © IEC 2024
c) the preparation of cable sample and test set-up has been arranged in a logical way;
d) Figure 1 has been added for illustration of the preparation of cable sample, DUT and test
set-up;
e) the temperature chamber temperature tolerance has been changed to ± 3 °C as done in
IEC 60794-1-22, method F1;
f) all required steps have been added to the subclause for temperature cycling as well as the
table for the minimum soak time and the figure for the cycle procedure, and removed the
reference to IEC 60794-1-22, method F1;
g) the maximum change in attenuation has been added to the details to be specified;
h) a new subclause 4.5 has been added for details to be reported.
The text of this International Standard is based on the following documents:
Draft Report on voting
86A/2357/CDV 86A/2409/RVC
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.
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/publications.
A list of all parts in the IEC 60794 series, published under the general title Optical fibre cables,
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, or
• revised.
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.

INTRODUCTION
This document defines the test method F12 to measure the attenuation behaviour (change in
attenuation) when an optical fibre cable with cable elements fixed at both ends is subjected to
temperature cycling. This test assesses the attenuation behaviour of a cable under a no-end
movement condition intended for termination with, for example, connectors or passive
components.
This document cancels and replaces method F12 of IEC 60794-1-22:2017, which will be
withdrawn. It includes an editorial revision, based on the new structure and numbering system
for optical fibre cable test methods. Additionally, technical changes were implemented. The
environmental tests contained in IEC 60794-1-22:2017 will be individually numbered in the
IEC 60794-1-2xx series. Each test method is now considered to be an individual document
rather than part of a multi-test method compendium. Full cross-reference details are given in
IEC 60794-1-2.
The main performance of a terminated cable is the optical transmission performance during
environmental variations (i.e. during temperature changes). Therefore, the test method F12 is
recommended to be performed for cables intended to be terminated with connectors. Moreover
this method can be optionally used as an indicator for cables terminated with hardened
connectors or fixed into a module and the fibres terminated with connectors.
IEC TR 62959 provides information on cable shrinkage characterisation of optical fibre cables
that consist of standard glass optical fibres for telecommunication applications. The
characterisation is directed to the effects of cable shrinkage or cable element shrinkage on the
termination of cables. Recommended test methods for the evaluation of cable shrinkage are
provided and classification using a “grading” system are given as guidance.

– 6 – IEC 60794-1-212:2024 © IEC 2024
OPTICAL FIBRE CABLES –
Part 1-212: Generic specification – Basic optical cable test procedures –
Environmental test methods – Temperature cycling with cable elements
fixed at both ends, method F12

1 Scope
This part of the IEC 60794 series defines the test procedure to examine the attenuation
behaviour (change in attenuation) when an optical fibre cable with cable elements fixed at both
ends is subjected to temperature cycling. This test assesses the attenuation behaviour of a
cable under a no-end movement condition intended for termination with, for example,
interconnecting devices or passive components.
NOTE IEC 60794-1-201 (method F1) is a general temperature cycling test for cables.
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 60793-1-46, Optical fibres – Part 1-46: Measurement methods and test procedures –
Monitoring of changes in optical transmittance
IEC 60794-1-1, Optical fibre cables – Part 1-1: Generic specification – General
IEC 60794-1-2, Optical fibre cables – Part 1-2: Generic specification – Basic optical cable test
procedures – General guidance
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60794-1-1 apply.
ISO and IEC maintain terminology databases for use in standardization at the following
addresses:
• IEC Electropedia: available at https://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp
___________
Under preparation. Stage at the time of publication: IEC FDIS 60794-1-201:2024.

4 Method F12 – Temperature cycling with cable elements fixed at both ends
4.1 Sample
The sample shall be taken from a finished cable length. The sample length shall be longer than
the device under test (DUT) to allow for connection to the optical measurement device outside
the temperature chamber and, if necessary, to have sufficient length to permit optical
measurements, as shown in Figure 1. The length of DUT shall be as specified in the relevant
specification. If the length of DUT is not specified, then a length of 10 m should be used.
4.2 Apparatus
The apparatus shall consist of the following:
a) a temperature chamber suitable to accommodate the DUT and to maintain the specified
temperature within ±3 °C;
b) attenuation monitoring equipment according to IEC 60793-1-46.
NOTE One example of a suitable chamber is given in IEC 60068-2-14:2009, Clause 8.
4.3 Procedure
4.3.1 Preparation of cable sample and DUT
The cable sample length shall be longer than the length of the DUT to allow for connection to
the optical measurement device outside the temperature chamber and, if necessary, to have
sufficient length to permit optical measurements. The DUT shall be coiled with a diameter larger
than the minimum bending diameter specified for the cable in service. At both ends of the length
of the DUT, all components of the cable shall be fixed together to avoid any relative movement
between the cable elements at the fixing point, as shown in Figure 1. All cable elements (for
example simplex cable) or at the individual cable units (for example simplex cable units within
a breakout cable) at both ends of the DUT where for example connectors or passive components
are intended to be terminated shall be fixed together. The fixing can be done, for example, by
clamping or adhesive bonding. Such fixing shall not affect the attenuation of the test sample.
4.3.2 Preparation of test
The DUT shall be placed in the temperature chamber, as shown in Figure 1, with a method of
storage that shall not affect the optical fibre with respect to expansion or contraction. The optical
fibre ends (outside the chamber) of the cable sample can be temporarily joint to pigtails. The
deployment of the cable sample outside the chamber shall not affect the results.

– 8 – IEC 60794-1-212:2024 © IEC 2024

Key
1 attenuation measurement device
2 temperature chamber
3 DUT, example shown of a simplex cable
4 all cable elements fixed at the ends of DUT
5 optical fibre of cable sample including the DUT
6 fibre connection (for example splice)
7 optical fibre
L length of DUT
Figure 1 – Preparation of the cable sample, DUT and test set-up
4.3.3 Preconditioning
The cable sample shall be preconditioned at standard atmospheric conditions as defined in
IEC 60794-1-2.
4.3.4 Temperature cycling
The temperature in the temperature chamber shall be at ambient temperature. Throughout this
procedure, the ambient temperature condition is the standard test condition as defined in
IEC 60794-1-2. The temperature cycles shall be carried out as shown in Figure 2 and as follows:
1) the temperature of the chamber shall be decreased to the low temperature T at a rate of
A2
cooling not to exceed 60 °C/h;
2) as soon as the temperature in the chamber has reached stable condition, the DUT shall be
exposed to the low temperature for the appropriate period t (see next bullet point);
3) a minimum soak time is given in Table 1; however, the soak time, t , shall be sufficient to
bring the DUT to equilibrium with the specified temperature;
4) the temperature in the chamber is then increased to the high temperature T at a rate of
B2
heating not to exceed 60 °C/h;
5) as soon as the temperature in the chamber has reached stable condition, the DUT shall be
exposed to the high temperature for the appropriate period t ;
6) the temperature in the chamber shall be decreased to ambient temperature at a rate of
cooling not to exceed 60 °C/h.

This procedure constitutes one cycle. If this is the intermediate step in a series of cycles, no
soak is required, and no measurement shall be taken.
The number of cycles specified in the relevant specification shall be carried out.
At the end of the cycling sequence, hold the DUT at ambient temperature for the appropriate
period t .
The change in attenuation shall be measured at ambient temperature at the start of the first
cycle, at the end of the soak time t at each of the specified temperatures steps (T / T ) in
1 A2 B2
the final cycle, and at ambient temperature at the end of the final cycle.
Table 1 – Minimum soak time t
Minimum soak times for a given sample mass (weight of DUT)
Sample mass Minimum soak time, t
kg h
Under 0,35 0,5
0,36 to 0,7 1
0,8 to 1,5 2
1,6 to 100 4
101 to 250 6
251 to 500 8
Over 501 12
If more than one sample is put into the chamber, the largest sample mass of all single samples should be compared
with the values in the table for the determination of the minimum soak time.
NOTE It is the responsibility of the tester to assure that the soak time is long enough to bring the cable to
equilibrium with the specified temperature.

– 10 – IEC 60794-1-212:2024 © IEC 2024

Key
t soak time
T low temperature
A2
T high temperature
B2
t unit of time
Figure 2 – Cycle procedure
4.3.5 Requirements
The maximum change in attenuation during and after the test shall be as spe
...