IEC 60794-1-23:2019

IEC 60794-1-23 ®
Edition 2.0 2019-10
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Optical fibre cables –
Part 1-23: Generic specification – Basic optical cable test procedures – Cable
element test methods
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IEC 60794-1-23 ®
Edition 2.0 2019-10
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Optical fibre cables –
Part 1-23: Generic specification – Basic optical cable test procedures – Cable

element test methods
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 33.180.10 ISBN 978-2-8322-7513-9

– 2 – IEC 60794-1-23:2019 RLV © IEC 2019
CONTENTS
FOREWORD . 5
1 Scope and object . 7
2 Normative references . 7
3 Terms and definitions . 8
4 General requirements . 8
5 Method G1: Bend test for optical cable elements . 8
5.1 Object . 8
5.2 Sample . 8
5.3 Apparatus . 8
5.4 Procedure . 8
5.5 Requirements . 8
5.6 Details to be specified . 8
6 Method G2: Ribbon dimensions and geometry – Visual method . 9
6.1 Object . 9
6.2 Sample . 9
6.3 Apparatus . 9
6.4 Procedure . 9
6.4.1 General . 9
6.4.2 Method 1 . 9
6.4.3 Method 2 . 9
6.5 Requirements . 9
6.6 Details to be specified . 10
6.7 Definitions of ribbon dimensions and geometry . 10
6.7.1 General . 10
6.7.2 Width and height. 10
6.7.3 Basis line . 10
6.7.4 Fibre alignment . 10
7 Method G3: Ribbon dimensions – Aperture gauge . 11
7.1 Object . 11
7.2 Sample . 11
7.3 Apparatus . 11
7.4 Procedure . 12
7.5 Requirement . 12
7.6 Details to be specified . 12
8 Method G4: Ribbon dimensions – Dial gauge (Test deleted obsoleted method) . 12
9 Method G5: Ribbon tear (separability) . 12
9.1 Object . 12
9.2 Sample . 12
9.3 Apparatus . 13
9.4 Procedure . 13
9.5 Requirements . 14
9.6 Details to be specified . 14
10 Method G6: Ribbon torsion . 14
10.1 Object . 14
10.2 Sample . 14

10.3 Apparatus . 14
10.4 Procedure . 15
10.5 Requirements . 15
10.6 Details to be specified . 15
11 Method G7: Tube kinking . 16
11.1 Object . 16
11.2 Sample . 16
11.3 Apparatus . 16
11.4 Procedure . 17
11.5 Requirements . 17
11.6 Details to be specified . 17
12 Method G8: Ribbon residual twist test . 18
12.1 Object . 18
12.2 Sample . 18
12.3 Apparatus . 18
12.4 Procedure . 18
12.5 Requirements . 19
12.6 Details to be specified . 19
13 Method G9: Bleeding and evaporation . 19
13.1 Object . 19
13.2 Sample . 19
13.3 Apparatus . 19
13.4 Procedure . 20
13.5 Requirements . 20
13.6 Details to be specified . 21
14 Method G10A: Stripping force stability of cabled optical fibres . 21
14.1 Object . 21
14.2 Sample . 21
14.2.1 Sample length . 21
14.2.2 Sample preparation . 21
14.3 Apparatus . 21
14.4 Procedure . 21
14.5 Requirements . 21
14.6 Details to be specified . 22
15 Method G10B: Strippability of optical fibre ribbons . 22
15.1 Object . 22
15.2 Sample . 22
15.3 Apparatus . 22
15.3.1 General . 22
15.3.2 Stripping tool . 22
15.3.3 Motor and slide (if used) . 23
15.4 Positioning and holding equipment . 23
15.5 Alcohol wipe . 23
15.6 Procedure . 23
15.7 Requirements . 24
15.8 Details to be specified . 24
16 Method G10C: Strippability of buffered optical fibres . 24
16.1 Object . 24

– 4 – IEC 60794-1-23:2019 RLV © IEC 2019
16.2 Sample . 24
16.3 Apparatus . 24
16.4 Procedure . 24
16.5 Requirements . 25
16.6 Details to be specified . 25
17 Method G11A: Tensile strength and elongation of buffer tubes and micro tubes at
break . 25
17.1 Object . 25
17.2 Sample . 25
17.2.1 General . 25
17.2.2 Preparation and conditioning of test pieces . 25
17.2.3 Determination of cross-sectional area . 28
17.2.4 Ageing treatment . 29
17.3 Apparatus . 29
17.4 Procedure . 30
17.5 Requirements . 31
18 Method G11B: Elongation of buffer tubes and micro tubes at low temperature . 31
18.1 Object . 31
18.2 Sample . 31
18.2.1 General . 31
18.2.2 Preparation of test pieces . 31
18.3 Apparatus . 32
18.4 Procedure . 32
18.5 Requirements . 33
18.6 Details to be specified . 33
Bibliography . 34

Figure 1 – Cross-sectional drawing illustrating fibre ribbon geometry . 10
Figure 2 – Aperture gauge . 11
Figure 3 – Sample preparation for ribbon separability test. 13
Figure 4 – Separability procedure . 14
Figure 5 – Torsion test . 15
Figure 6 – Tube kinking test . 16
Figure 7 – Bleeding and evaporation test set-up . 20
Figure 8 – Dumb-bell test piece . 27
Figure 9 – Small dumb-bell test piece . 28
Figure 10 – Punch end showing groove . 28
Figure 11 – Test pieces cut by grooved punch . 28
Figure 12 – Machine for preparing test pieces . 30

Table 1 – Examples of test apparatus dimensions for tube kinking . 17
Table 2 – Condition of stripped samples . 23

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
OPTICAL FIBRE CABLES
Part 1-23: Generic specification – Basic optical
cable test procedures – Cable element test methods

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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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) 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.
This redline version of the official IEC Standard allows the user to identify the changes
made to the previous edition. A vertical bar appears in the margin wherever a change has
been made. Additions are in green text, deletions are in strikethrough red text.

– 6 – IEC 60794-1-23:2019 RLV © IEC 2019
International Standard IEC 60794-1-23 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 2012. It constitutes a
technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) addition of a new test method G9: Bleeding and evaporation (formerly known as
method E15 in IEC 60794-1-21:2015);
b) addition of a new test method G10A: Stripping force stability of cabled optical fibres
(formerly known as method E5A in IEC 60794-1-21:2015);
c) addition of a new test method G10B: Strippability of optical fibre ribbons (formerly known
as method E5B in IEC 60794-1-21:2015);
d) addition of a new test method G10C: Strippability of buffered optical fibres (formerly known
as method E5C in IEC 60794-1-21:2015);
e) addition of a new test method G11A: Tensile strength and elongation of buffer tubes
(included in IEC 60811-501);
f) addition of a new test method G11B: Elongation of buffer tubes at low temperature (included
in IEC 60811-505);
g) clarification of the sample preparation procedure in method G5: Ribbon tear (separability);
The text of this International Standard is based on the following documents:
CDV Report on voting
86A/1912/CDV 86A/1945/RVC
Full information on the voting for the approval of this International Standard 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 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 "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.
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 FIBRE CABLES
Part 1-23: Generic specification – Basic optical
cable test procedures – Cable element test methods

1 Scope and object
This part of IEC 60794 describes test procedures to be used in establishing uniform
requirements for the geometrical, material, mechanical, environmental properties of optical fibre
cable elements.
This document applies to optical fibre cables for use with telecommunication equipment and
devices employing similar techniques, and to cables having a combination of both optical fibres
and electrical conductors.
The object of this part of IEC 60794 is to define test procedures to be used in establishing
uniform requirements for the geometrical, material, mechanical, environmental properties of
optical fibre cable elements.
Throughout the document, the wording "optical cable" may can also include optical fibre units,
microduct fibre units, etc.
General requirements and definitions are given in IEC 60794-1-20 and a complete reference
guide to test method of all types in the IEC 60794-1-2.
NOTE The environmental testing of optical fibre ribbon would be valuable for some applications. Useful information
about suitable test methods can be found in the optical fibre standards IEC 60793-1-50,
IEC 60793-1-51, IEC 60793-1-52, and IEC 60793-1-53.
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
IEC 60794-1-31:2018, Optical fibre cables – Part 1-31: Generic specification – Optical cable
elements – Optical fibre ribbon
IEC 60793-1-32:2018, Optical fibres – Part 1-32: Measurement methods and test procedures –
Coating strippability
IEC 60793-1-40, Optical fibres – Part 1-40: Measurement methods and test procedures –
Attenuation measurement methods
IEC 60794-3:2001, Optical fibre cables – Part 3: Sectional specification – Outdoor cables
IEC 60793-1-46, Optical fibres – Part 1-46: Measurement methods and test procedures –
Monitoring of changes in optical transmittance

– 8 – IEC 60794-1-23:2019 RLV © IEC 2019
IEC 60811-401, Electric and optical fibre cables – Test methods for non-metallic materials –
Part 401: Miscellaneous tests – Thermal ageing methods – Ageing in an air oven
3 Terms and definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
4 General requirements
IEC 60794-1-2 is the reference guide to test methods of all types. It shall be considered for
general requirements and definitions.
5 Method G1: Bend test for optical cable elements
5.1 Object
The purpose of this test is to characterize cable elements for splicing purposes by determining
the attenuation increase of an optical cable element (fibre, ribbon, core tube, breakout unit, etc.)
element when bent within a splice closure or similar device.
5.2 Sample
The length of the sample of optical cable element shall be sufficient to carry out the testing
specified.
5.3 Apparatus
The apparatus consists of
a) a mandrel having a smooth surface with diameter as stated in the detail specification, and
b) an attenuation measuring apparatus for the determination of attenuation change (see
according to the test methods of IEC 60793-1-40 and IEC 60793-1-46).
5.4 Procedure
The element to be tested shall be loosely wound on the mandrel at minimal tension; the number
of turns shall be stated in the detail specification.
In order to measure the attenuation increase caused by bending, allowance should be made for
the intrinsic attenuation of the fibre.
5.5 Requirements
Any increase in attenuation shall comply with the limits shown in the detail specification.
5.6 Details to be specified
The detail specification shall include the following:
a) optical test wavelength;
b) diameter of the mandrel;
c) number of turns;
d) apparatus and attenuation measuring technique;
e) temperature at which the evaluation shall be performed if different from room temperature.
6 Method G2: Ribbon dimensions and geometry – Visual method
6.1 Object
The purpose of this test is to determine the geometry of an optical fibre ribbon as defined by
the parameters of width, height and fibre alignment, for the purpose of type testing to assume
proper manufacturing process control. This test is not necessarily suitable for final product
inspection and, unless otherwise specified, shall not be used for that purpose.
6.2 Sample
The number of samples to be tested shall be specified in the detail specification. The selected
samples shall be statistically independent and representative of the ribbon population tested.
6.3 Apparatus
The apparatus consists of a microscope or profile projector with appropriate magnification.
6.4 Procedure
6.4.1 General
Either of the two following procedures methods described in 6.4.2 and 6.4.3 may be used.
For the specified number of samples, all dimensions shall be measured as average as well as
maximum and minimum values.
NOTE Care should be taken that the preparation of the sample does not change the structure
of the fibre ribbon and represents an undisturbed image of the fibre cladding and ribbon cross-
section.
6.4.2 Method 1
The sample is prepared by cutting it perpendicular to the axis of the ribbon and placing it in a
curable resin or in a tool which holds the ribbon. If necessary, the sample shall be ground and
polished to prepare a smooth perpendicular end face. The prepared sample is secured with its
end face perpendicular to the optical path and measured by means of a microscope or profile
projector.
6.4.3 Method 2
Place the ribbon in a ribbon fibre holder and remove 20 mm to 25 mm of the fibre coating and
matrix material with the ribbon hot sheath stripping tool and wipe the stripped portion of the
fibres clean with an alcohol-moistened pad. Adjust the position of the ribbon in the ribbon fibre
holder and cleave the fibres at a distance of 250 µm to 500 µm from the stripped edge of the
ribbon. Cut and polish the other end of the ribbon, and illuminate it with a collimated light source.
Align and measure the cleaved end of the ribbon under microscope.
NOTE Care should be taken that the preparation of the sample does not change the structure of the fibre ribbon
and represents an undisturbed image of the fibre cladding and ribbon cross-section.
6.5 Requirements
Unless otherwise specified in the detail specification, the width, height and fibre alignment shall
be in accordance with IEC 60794-3:2001, Table 1 IEC 60794-1-31:2018.

– 10 – IEC 60794-1-23:2019 RLV © IEC 2019
6.6 Details to be specified
The detail specification shall include the following:
a) permissible maximum and minimum values;
b) limits for average values;
c) number of samples tested.
6.7 Definitions of ribbon dimensions and geometry
6.7.1 General
The following definitions apply to a fibre ribbon cross-section as shown in Figure 1. The figure
illustrates an example for a 4-fibre ribbon, where a is the diameter of a coloured fibre.
NOTE In consideration of the precision of fibre geometric attributes and the relatively larger precision of ribbon
geometry requirements, it is acceptable for glass core/glass cladding fibres to use the edge of the cladding for the
measurements of 6.7.3 and 6.7.4 in lieu of the fibre centres. In this case, the measurements shall can be made on
the same side of all fibres (e.g. top or bottom, left or right side).

Figure 1 – Cross-sectional drawing illustrating fibre ribbon geometry
6.7.2 Width and height
The width w and height h of the ribbon are the dimensions of the minimum rectangular area
enclosing the ribbon cross-section.
6.7.3 Basis line
The basis line is given that line in the cross-section of an optical fibre ribbon as the straight line
crossing the fibre centres of the first fibre (fibre 1) and the last fibre (fibre n) of the fibre ribbon,
as shown in Figure 1 as dotted line. This line is used as the reference plane for the fibre
alignment measurements.
6.7.4 Fibre alignment
6.7.4.1 Horizontal fibre separation
The horizontal separation of fibres is the distance of the orthogonal projection of two fibre
centres on the basis line in the fibre ribbon cross-section.

Two horizontal separation parameters can be distinguished:
a) centre-centre distance d between adjacent fibres;
b) centre-centre distance b between the extreme fibres.
6.7.4.2 Planarity
The planarity p of the fibre ribbon structure is the sum of the maximum positive and absolute
value of the maximum negative vertical separation of the fibres.
The vertical separation of the fibres is the orthogonal distance from the fibre centre to the basis
line. The vertical separation is positive for fibres "above" the basis line and negative for fibres
"below" the basis line.
7 Method G3: Ribbon dimensions – Aperture gauge
7.1 Object
The purpose of this test is to verify the functional performance of a ribbon. In order to ensure
functional performance, the dimensions of edge bonded ribbons may be controlled and verified
for final inspection purposes with an aperture gauge. The intent is to verify that the end portion
of a ribbon can be inserted into and would be reasonably aligned to the guide slots of
commercial stripping tools. This method is under consideration for encapsulated ribbons.
7.2 Sample
Unless otherwise specified in the detail specification, five representative ribbon samples, each
with a minimum length of 50 mm, shall be taken from the ribbon to be tested.
7.3 Apparatus
An aperture gauge, as shown in Figure 2, having an aperture based on the dimensions shown
in IEC 60794-3:2001, Table 1, may shall be used to assess the overall dimensions of a ribbon.
The values for ribbon width (w) and ribbon height (h) of Figure 2 shall be the nominal ribbon
dimensions as established using method G2 in an appropriate quality assessment scheme.

Figure 2 – Aperture gauge
– 12 – IEC 60794-1-23:2019 RLV © IEC 2019
7.4 Procedure
The ribbon sample to be tested is held in the middle, and a 10 mm end portion is inserted
through the aperture gauge.
7.5 Requirement
It must shall be possible for the 10 mm ribbon end portion to be freely inserted through the
aperture gauge without mechanical damage to the sample.
7.6 Details to be specified
The detail specification shall include the following:
a) dimensions of the aperture gauge;
b) number of samples to be tested.
8 Method G4: Ribbon dimensions – Dial gauge (Test deleted obsoleted
method)
9 Method G5: Ribbon tear (separability)
9.1 Object
The purpose of this test is to assure sufficient tear resistance for ribbons where the fibres are
not required to be separable, or to assure sufficient separability of the fibres for ribbons where
the fibres are required to be separated. The intention of this test is to be able to tear by hand
without damage.
9.2 Sample
For an n fibre ribbon, n/2 specimens, each with a minimum length of 100 mm, are taken from
lengths of approximately 1 m each from the fibre ribbon.
The fibres to be tested are separated with a knife or other suitable method on a suitable length
for clamping (see Figure 3) for x samples (x, typically 3 to 5, to be specified in the detail
specification). One fibre is separated from the other fibres in the ribbon. For x more samples,
two fibres are separated from the other fibres in the ribbon, etc. up to n/2 fibres.
A number of samples of fibre ribbon, as specified in the detail specification, typically 3 to 5,
shall be selected from the ribbon or ribbons to be tested. The length of each sample shall be
sufficient to provide the number of test specimens as detailed below.
For an n fibre ribbon, n/2 specimens are taken from each of the samples above. Each specimen
shall be 100 mm minimum length, consistent with Figure 3.
Prepare the n/2 specimens involving increasing numbers of fibres to be separated as a ribbon
unit. That is, a specimen for fibre 1; a specimen for fibres 1 to 2; a specimen for fibres 1 to 3;
etc.
The fibres to be tested are separated with a knife or other suitable method on a suitable length
for clamping, per Figure 3.
For the first sample, the preparation of the test sequence shall be to separate one fibre from
the other fibres in the ribbon in the first specimen. Then, separate a unit of two fibres from the
next specimen. Then, units of three, four, etc. fibres are separated in the other specimens, up
to a unit of n/2 fibres in the last specimen.

Do the same preparation for all the other samples.
NOTE If n is an odd number, replace n/2 with (n-1)/2 in the above description.
Dimensions in millimetres
Figure 3 – Sample preparation for ribbon separability test
9.3 Apparatus
The apparatus consists of
a) a tensile strength measuring apparatus with suitable clamping devices and suitable force
recording functions, and
b) a microscope with at least 100 × magnification.
9.4 Procedure
The specimen is inserted into the strength measuring apparatus, as shown in Figure 4. The
fibres to be tested are torn at a speed of approximately 100 mm/min to 500 mm/min. The force
to tear the fibres on a minimum length of 50 mm is continuously recorded.
In the case where fibres are required to be separated, the primary coating of the separated
fibre(s) shall be visually inspected by means of a microscope.
The procedure is repeated for the specimens involving separation of fibre 1, fibres 1 to 2, fibres
1 to 3, etc. up through fibres 1 to n/2.

– 14 – IEC 60794-1-23:2019 RLV © IEC 2019

Figure 4 – Separability procedure
9.5 Requirements
The primary requirement is to be able to make the tear without fibre damage (coating damage
or fibre breakage). For ribbons where the fibres are required to be separated, the coloured
primary coating of the separated fibre(s) shall be effectively free from ribbon matrix residues.
Any colour coding of fibres shall remain sufficiently intact within any 25 mm segment to enable
individual fibres to be distinguished from each other.
The minimum or maximum and mean tear forces shall be as specified in the detail specification.
9.6 Details to be specified
The detail specification shall include the following:
a) minimum and mean tear force, in N, when fibres are not required to be separated;
b) maximum and mean tear force, in N, as required by the detail specification, when fibres are
required to be separated;
c) number of samples;
d) type of ribbon (separable or non-separable).
10 Method G6: Ribbon torsion
10.1 Object
The purpose of this test is to verify the mechanical and functional integrity of the fibre ribbon
structure. The test determines the capability of the ribbon to withstand torsion without
delamination, whilst maintaining the fibre separability where required.
10.2 Sample
Unless otherwise specified in the detail specification, five representative samples, each with a
minimum length of 120 mm, are obtained from the ribbon to be tested.
10.3 Apparatus
The testing apparatus, an example of which is in Figure 5, consists of two vertically positioned
clamps to hold the sample while it is twisted under a minimum tension of 1 N. The minimum
length to be tested is 100 mm.

Dimensions in millimetres
Figure 5 – Torsion test
10.4 Procedure
The sample is securely fixed in the apparatus and twisted in increments of 180° ± 5° within a
time of 2 s. The minimum dwell time after each twist increment is 5 s. The incremental twisting
is continued to the value(s) agreed upon between the manufacturer customer and user supplier,
as defined in the detail specification, or until delamination occurs.
10.5 Requirements
The ribbon shall withstand the number of 180° turns until delamination occurs, as given stated
in the detail specification until delamination occurs.
10.6 Details to be specified
The detail specification shall include the following:
a) number of samples;
b) number of turns.
– 16 – IEC 60794-1-23:2019 RLV © IEC 2019
11 Method G7: Tube kinking
11.1 Object
The purpose of this test is to determine the ability of tubes containing optical fibres to withstand
mechanical stresses encountered during cable installation and splicing. The test is carried out
on tubes taken from an optical cable.
11.2 Sample
Tube containing fibres, with a length of at least L + 50 mm, shall be taken from an optical fibre
cable.
Five (5) samples shall be tested, unless otherwise specified.
11.3 Apparatus
The apparatus consists of a testing device as shown in Figure 6.

Key
L length of tube under test
L distance between the tube clamping point of the movable clamp and the tube clamping point of the fixed clamp
at the start of the test
L moving distance (the length of which determines the reduction of the ellipse dimension)
The dimensions of the apparatus are given in Table 1.
NOTE 1 The minimum diameter of the loop is not fixed by a curvature in the test equipment, but only controlled by
the fixed len
...