IEC 60794-1-216:2025

IEC 60794-1-216 ®
Edition 1.0 2025-04
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Optical fibre cables –
Part 1-216: Generic specification – Basic optical cable test procedures –
Environmental test methods – Compound flow (drip), Method F16

Câbles à fibres optiques –
Partie 1-216: Spécification générique – Procédures fondamentales d’essais des
câbles optiques – Méthodes d’essais d’environnement – Écoulement
(égouttement) des matériaux de remplissage, méthode F16
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IEC 60794-1-216 ®
Edition 1.0 2025-04
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Optical fibre cables –
Part 1-216: Generic specification – Basic optical cable test procedures –

Environmental test methods – Compound flow (drip), Method F16

Câbles à fibres optiques –
Partie 1-216: Spécification générique – Procédures fondamentales d’essais des

câbles optiques – Méthodes d’essais d’environnement – Écoulement

(égouttement) des matériaux de remplissage, méthode F16

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 33.180.10  ISBN 978-2-8327-0371-7

– 2 – IEC 60794-1-216:2025 © IEC 2025
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 General requirements. 6
5 Sample . 6
5.1 Number and type of samples. 6
5.2 Sample length . 7
5.3 Sample preparation. 7
5.4 Sample termination . 8
6 Apparatus . 8
7 Procedure . 8
8 Requirements . 9
9 Details to be specified . 9
10 Details to be reported . 9

Figure 1 – Preparation of the sample . 7

Table 1 – Values and tolerances for the length of sample . 7

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
OPTICAL FIBRE CABLES –
Part 1-216: Generic specification – Basic optical cable test procedures –
Environmental test methods – Compound flow (drip), Method F16

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
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3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
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6) All users should ensure that they have the latest edition of this publication.
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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
respect thereof. As of the date of publication of this document, IEC had not received notice of (a) patent(s), which
may be required to implement this document. However, implementers are cautioned that this may not represent
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 60794-1-216 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 the second edition of 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) Addition of new Clause 10.
– 4 – IEC 60794-1-216:2025 © IEC 2025
The text of this International Standard is based on the following documents:
Draft Report on voting
86A/2544/FDIS 86A/2555/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.
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.
INTRODUCTION
This document cancels and replaces Method F16 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 numbering of this test method continues the F-series numbering sequence of
IEC 60794-1-22:2017.
– 6 – IEC 60794-1-216:2025 © IEC 2025
OPTICAL FIBRE CABLES –
Part 1-216: Generic specification – Basic optical cable test procedures –
Environmental test methods – Compound flow (drip), Method F16

1 Scope
This part of IEC 60794 defines test procedures to ensure the filling and flooding compounds
will not flow from a filled or flooded fibre optic cable, at stated temperatures.
NOTE The environmental testing of optical cable would be valuable for some applications. Useful information about
suitable test methods can be found in the optical fibre standards IEC 60794-1-2.
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 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 60794-1-2 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
4 General requirements
IEC 60794-1-2 is the reference guide to test methods of all types.
5 Sample
5.1 Number and type of samples
Unless otherwise specified in the detail specification, prepare two cable samples for testing
from each cable sample to be evaluated. Each cable sample shall be representative of the cable
type specified by the detail specification.

5.2 Sample length
Unless otherwise specified in the detail specification, each sample shall be 200 mm ± 5 mm in
length.
5.3 Sample preparation
Prepare each cable sample as follows, making any modifications as required in 5.4.
a) Remove a 100 mm ± 2,5 mm section of the outer sheathing material from one end.
b) Remove all cable elements (e.g. armour, screens, inner sheaths, helically applied strength
elements, water blocking tapes, other core wraps, etc.), leaving only the buffer tubes and
fillers used to maintain cable roundness for a length of 80 mm ± 2,5 mm from the same
cable end. Do not disturb the remainder of the cable (e.g. the final buffer tubes which contain
the optical fibres or fillers used for roundness). Unless otherwise stated, the sample should
be prepared as shown in Figure 1 and Table 1

Key
l remove outer sheathing material
l remove all remaining non-intrinsic cable elements
l sample length
Figure 1 – Preparation of the sample
Table 1 – Values and tolerances for the length of sample
l l l
1 2 3
Length
100 80 200
(mm)
Tolerance
±2,5 ±2,5 ±5
(mm)
c) Remove loosely adhered quantities of filling or flooding material disturbed in 5.3 a) or 5.3
b) but ensure that the sample remains essentially coated by the filling or flooding material
(i.e. do not wipe clean).
d) For cable designs containing components such as fibre bundles or ribbons which might
move under their own weight during the test, secure such components at the unprepared
end of the sample in a manner which does not disturb the remainder of the sample. Such
components can be secured by clamps, epoxy plugs or other means meeting the objectives
of the procedure.
e) When permitted by the detail specification, the upper ends of buffer tubes or loose tubes
may be sealed to simulate long length cable sections.

– 8 – IEC 60794-1-216:2025 © IEC 2025
5.4 Sample termination
If allowed by the detail specification, terminate the lower end of the cable sample according to
the manufacturer's recommendations for terminating the cable in actual use. Parts of item 5.3
procedure can be affected by this termination, but the objective of item 5.3 is to be followed.
6 Apparatus
The following apparatus and equipment are required to perform this test.
a) Chamber
A temperature chamber large enough to hold the samples in a vertical position, with
sufficient thermal capacity to maintain the specified temperatures for the duration of the
test. If the temperature chamber is of a circulating air type, the air shall not blow directly on
the test samples. The chamber shall be capable of operating to within ±3 °C of the specified
test temperature. It is necessary to install arrangements inside the chamber to hang the
sample. In order to avoid the concentration of thermal energy at the point of connection to
the sample, it is necessary to use clamps that are designed to not cause thermal
concentration.
b) Container
A non-hygroscopic container to catch dripping material.
c) Analytical balance
7 Procedure
The following steps shall be taken.
a) Preheat the chamber to the temperature specified in the detail specification.
b) Hang each prepared sample in the chamber, which is suspended in a vertical position with
the prepared end down. Place a pre-weighed clean collection container directly under (but
not contacting) the suspended sample.
c) If permitted by the detail specification, preconditioning may be performed as defined in c)
1) to c) 3); otherwise, continue with d).
1) Stabilize the chamber temperature and, unless otherwise specified in the detail
specification, precondition each sample for a period of 1 h.
2) At the end of the specified preconditioning time, replace the collection container with
another pre-weighed clean collection container. Weigh the preconditioning collection
container to measure the quantity of filling or flooding compound which can have dripped
out of the cable during the preconditioning. A measured quantity greater than the
specified preconditioning limit shall constitute a failure. Unless otherwise specified in
the detail specification, the preconditioning limit shall be 0,5 % of the total cable sample
weight or 0,5 g, whichever is the smaller.
3) Continue testing for 23 h, unless otherwise specified in the detail specification, and
con
...