IEC 60793-2-20:2007

IEC 60793-2-20
Edition 2.0 2007-10
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Optical fibres –
Part 2-20: Product specifications – Sectional specification for category A2
multimode fibres
Fibres optiques –
Partie 2-20: Spécifications de produits – Spécification intermédiaire pour les
fibres multimodales de catégorie A2

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IEC 60793-2-20
Edition 2.0 2007-10
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Optical fibres –
Part 2-20: Product specifications – Sectional specification for category A2
multimode fibres
Fibres optiques –
Partie 2-20: Spécifications de produits – Spécification intermédiaire pour les
fibres multimodales de catégorie A2

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
N
CODE PRIX
ICS 33.180.10 ISBN 2-8318-9333-X

– 2 – 60793-2-20 © IEC:2007
CONTENTS
FOREWORD.0H3

1 Scope.1H5
2 Normative references .2H5
3 Specifications .3H6
3.1 General .4H6
3.2 Dimensional requirements .5H6
3.3 Mechanical requirements.6H7
3.4 Transmission requirements .7H7
3.5 Environmental requirements .8H8

Annex A (normative) Family specifications for A2a multimode fibres .9H9
Annex B (normative) Family specifications for A2b multimode fibres .10H11
Annex C (normative) Family specifications for A2c multimode fibres .11H13

Bibliography.12H15

Table 1 – Relevant dimensional attributes and measurement methods.13H6
Table 2 – Requirements common to category A2 fibres.14H7
Table 3 – Additional attributes required in the family specifications.15H7
Table 4 – Relevant mechanical attributes and test methods .16H7
Table 5 – Requirements common to category A2 fibres.17H7
Table 6 – Relevant transmission attributes and measurement methods.18H8
Table 7 – Requirements common to fibres of category A2.19H8
Table 8 – Relevant environmental attributes and test methods.20H8
Table A.1 –Dimensional requirements specific to A2a fibres .21H9
Table A.2 – Mechanical requirements specific to A2a fibres.22H9
Table A.3 – Transmission requirements specific to A2a fibres.23H9
Table A.4.1 – Environmental exposure tests .24H10
Table A.4.2 – Attributes measured .25H10
Table B.1 – Dimensional requirements specific to A2b fibres .26H11
Table B.2 – Mechanical requirements specific to A2b fibres.27H11
Table B.3 – Transmission requirements specific to A2b fibres.28H11
Table B.4.1 – Environmental exposure tests .29H12
Table B.4.2 – Attributes measured .30H12
Table C.1 – Dimensional requirements specific to A2c fibres .31H13
Table C.2 – Mechanical requirements specific to A2c fibres.32H13
Table C.3 – Transmission requirements specific to A2c fibres.33H13
Table C.4.1 – Environmental exposure tests .34H14
Table C.4.2 – Attributes measured.35H14

60793-2-20 © IEC:2007 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
OPTICAL FIBRES −
Part 2-20: Product specifications –
Sectional specification for category A2 multimode fibres

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
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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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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 60793-2-20 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 2002. It constitutes a
technical revision.
The main changes from the previous edition are:
– the addition of tensile strength requirement;
– the removal of water immersion requirement;
– the addition of environmental requirements.

– 4 – 60793-2-20 © IEC:2007
The text of this standard is based on the following documents:
CDV Result of voting
86A/1129/CDV 86A/1151/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 of 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 maintenance result 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.
60793-2-20 © IEC:2007 – 5 –
OPTICAL FIBRES −
Part 2-20: Product specifications –
Sectional specification for category A2 multimode fibres

1 Scope
This part of IEC 60793-2 is applicable to optical fibres type A2a, A2b, and A2c. These fibres
are used or can be incorporated in information transmission equipment and optical fibre
cables (typically up to 2 km).
Three types of requirements apply to these fibres:
– general requirements as defined in IEC 60793-2;
– specific requirements common to the category A2 multimodal fibres covered in this
standard and which are given in Clause 3;
– particular requirements applicable to individual fibre types or specific applications, which
are defined in the normative family specification annexes.
2 Normative references
The following referenced documents are indispensable for the application 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 60793-1-20, Optical fibres – Part 1-20: Measurement methods and test procedures –
Fibre geometry
IEC 60793-1-21, Optical fibres – Part 1-21: Measurement methods and test procedures –
Coating geometry
IEC 60793-1-22, Optical fibres – Part 1-22: Measurement methods and test procedures –
Length measurement
IEC 60793-1-30, Optical fibres – Part 1-30: Measurement methods and test procedures –
Fibre proof test
IEC 60793-1-31, Optical fibres – Part 1-31: Measurement methods and test procedures –
Tensile strength
IEC 60793-1-40, Optical fibres – Part 1-40: Measurement methods and test procedures –
Attenuation
IEC 60793-1-41, Optical fibres – Part 1-41: Measurement methods and test procedures –
Bandwidth
IEC 60793-1-43, Optical fibres – Part 1-43: Measurement methods and test procedures –
Numerical aperture
IEC 60793-1-46, Optical fibres – Part 1-46: Measurement methods and test procedures –
Monitoring of changes in optical transmittance

– 6 – 60793-2-20 © IEC:2007
IEC 60793-1-50, Optical fibres – Part 1-50: Measurement methods and test procedures –
Damp heat (steady state)
IEC 60793-1-51, Optical fibres – Part 1-51: Measurement methods and test procedures – Dry
heat
IEC 60793-1-52, Optical fibres – Part 1-52: Measurement methods and test procedures –
Change of temperature
IEC 60793-2:2003, Optical fibres − Part 2: Product specifications – General
IEC 62048, Optical fibres – Reliability – Power law theory
3 Specifications
3.1 General
The fibre shall consist of a glass core and a glass cladding in accordance with 4.2 of
IEC 60793-2.
The term “glass” refers to material usually consisting of non-metallic oxides. The composition
of some fibres may be all glass, or glass and glass/hard polymeric composites.
3.2 Dimensional requirements
Relevant dimensional attributes and measurement methods are indicated in Table 1.
Requirements common to all fibres in category A2 appear in Table 2.
Table 3 lists additional attributes that shall be specified by each family specification.
Table 1 – Relevant dimensional attributes and measurement methods
Attribute Measurement
method
Cladding diameter IEC 60793-1-20
Core diameter IEC 60793-1-20
Core non-circularity IEC 60793-1-20
Core-cladding concentricity IEC 60793-1-20
error
Coating diameter IEC 60793-1-21
Fibre length IEC 60793-1-22
60793-2-20 © IEC:2007 – 7 –
Table 2 – Requirements common to category A2 fibres
Attribute Unit Limits
Core non-circularity % ≤4
a
Coating diameter
μm
b
Fibre length km
a
The diameter of the coating is dependent on

the cable structure and applications.
b
Length requirements vary and should be

agreed between supplier and customer.

Table 3 – Additional attributes required in the family specifications
Attributes
Cladding diameter
Core diameter
3.3 Mechanical requirements
Relevant mechanical attributes and test methods are indicated in Table 4.
Requirements common to all fibres in category A2 are given in Table 5.
Table 4 – Relevant mechanical attributes and test methods
Attribute Test method
Tensile strength IEC 60793-1-31
(0,5 m sample length)
Strain rate 3 % to 5 % / minute
Proof test IEC 60793-1-30
Table 5 – Requirements common to category A2 fibres
Attribute Unit Limit
a
Proof stress level GPa
≥ 0,345
a
For the relation between different units, see
4.4 of IEC 62048.
3.4 Transmission requirements
Relevant transmission attributes and measurement methods are given in Table 6.
Requirements common to all fibres in category A2 are given in Table 7.

– 8 – 60793-2-20 © IEC:2007
Table 6 – Relevant transmission attributes and measurement methods
Attribute Test
a
Attenuation coefficient IEC 60793-1-40
Optical continuity IEC 60794-1-40 or
IEC 60793-1-46
a
Modal bandwidth IEC 60793-1-41
a
IEC 60793-1-43
Numerical aperture
Theoretical numerical aperture IEC 60793-1-20
Change of optical transmission IEC 60793-1-46
a
When measuring attenuation and modal bandwidth and numerical
aperture, the appropriate launching conditions should be applied -
as specified in Annex A of the specified part of IEC 60793-1. The
testing length shall be agreed between customer and supplier

Table 7 – Requirements common to fibres of category A2
Attribute Unit Limit
a
Attenuation coefficient at λ nm dB/km
≤10
Y
a
Modal bandwidth at λ nm ≥10
Y MHz·km
Theoretical numerical aperture Unitless 0,23 ± 0,03 or
0,26 ± 0,03
a
The wavelength, λ , shall be agreed between supplier and customer.
Y
3.5 Environmental requirements
Relevant environmental attributes and test methods are given in Table 8.
Table 8 – Relevant environmental attributes and test methods
Attribute Test method
Damp heat tests IEC 60793-1-50
Dry heat tests IEC 60793-1-51
Change of temperature tests IEC 60793-1-52

60793-2-20 © IEC:2007 – 9 –
Annex A
(normative)
Family specifications for A2a multimode fibres

The following clauses and tables contain the particular requirements applicable to A2a fibres.
Common requirements, repeated here for ease of reference from the sectional specification,
are noted by an entry in the “Reference” column. Relevant notes from the sectional
SS
specification are not repeated but indicated with a superscript “ ”.
A.1 Dimensional requirements
Table A.1 contains dimensional requirements specific to A2a fibres.
Table A.1 – Dimensional requirements specific to A2a fibres
Attribute Unit Limit Reference
Cladding diameter
μm 140 ± 10
Core diameter μm 100 ± 4
Core non-circularity % ≤4 3.2
Coating diameter [See 3.2] 3.2
μm
Fibre length km [See 3.2] 3.2
A.2 Mechanical requirements
Table A.2 contains mechanical requirements specific to A2a fibres.
Table A.2 – Mechanical requirements specific to A2a fibres
Attribute Unit Limit Reference

SS
Proof stress level GPa 3.3
≥0,345
A.3 Transmission requirements
Table A.3 contains transmission requirements specific to A2a fibres.
Table A.3 – Transmission requirements specific to A2a fibres
Attribute Unit Limit Reference

SS
dB/km 3.4
Attenuation coefficient at λ nm ≤10
Y
SS
3.4
Modal bandwidth at λ nm MHz·km ≥10
Y
Theoretical numerical aperture Unitless 3.4
0,23 ± 0,03 or
0,26 ± 0,03
– 10 – 60793-2-20 © IEC:2007
A.4 Environmental requirements
Tables A.4.1 and A.4.2 contain environmental exposure tests and measurement methods
specific to A2a fibres. Test and measurements shall be documented in two forms:
• relevant environmental attributes, test methods and test conditions are given in Table
A.4.1;
• measurements of a particular mechanical and transmission attribute that may change
during exposure to the environmental test are listed in Table A.4.2.

Table A.4.1 – Environmental exposure tests
Environment Test method Test condition
Damp heat IEC 60793-1-50 +70 °C, 85 % RH,
30 days
Dry heat IEC 60793-1-51 +70 °C,
30 days
Change of temperature IEC 60793-1-52 T : -20 °C, T :+70 °C
a b
Table A.4.2 – Attributes measured
Attributes Unit Limits Reference
Change in optical transmission  dB/km
≤ 2
at attenuation coefficient at
SS
λ nm
Y
Tensile strength GPa at 15 % and 50 % 15 % - 2,20 3.2
Weibull Probability Levels 50 % - 2,41

These tests are normally conducted periodically as type-tests for a fibre design. Unless
otherwise indicated, the recovery period allowed between the completion of the environmental
exposure and measuring the attributes shall be as stated in the particular environmental test
method.
60793-2-20 © IEC:2007 – 11 –
Annex B
(normative)
Family specifications for A2b multimode fibres

The following clauses and tables contain the particular requirements applicable to A2b fibres.
Common requirements, repeated here for ease of reference from the sectional specification,
are noted by an entry in the “Reference” column. Relevant notes from the sectional
”
SS
specification are not repeated but indicated with a superscript “ .
B.1 Dimensional requirements
Table B.1 contains dimensional requirements specific to A2b fibres.
Table B.1 – Dimensional requirements specific to A2b fibres
Attribute Unit Limit Reference
Cladding diameter μm 240 ± 10
Core diameter
μm 200 ± 8
Core non-circularity % 3.2
≤4
Coating diameter μm [See 3.2] 3.2
Fibre length km [See 3.2] 3.2
B.2 Mechanical requirements
Table B.2 contains mechanical requirements specific to A2b fibres.
Table B.2 – Mechanical requirements specific to A2b fibres
Attribute Unit Limit Reference

SS
Proof stress level GPa 3.3
≥0,345
B.3 Transmission requirements
Table B.3 contains transmission requirements specific to A2b fibres.
Table B.3 – Transmission requirements specific to A2b fibres
Attribute Unit Limit Reference

SS
Attenuation coefficient at λ nm dB/km ≤10 3.4
Y
SS
Modal bandwidth at λ nm ≥10 3.4
MHz·km
Y
Theoretical numerical aperture Unitless 0,23 ± 0,03 or 3.4
0,26 ± 0,03
– 12 – 60793-2-20 © IEC:2007
B.4 Environmental requirements
Tables B.4.1 and B.4.2 contain environmental exposure tests and measurement methods
specific to A2b fibres. Test and measurements shall be documented in two forms:
• relevant environmental attributes, test methods and test conditions are given in Table
B.4.1;
• measurements of a particular mechanical and transmission attribute that may change
during exposure to the environmental test are listed in Table B.4.2.

Table B.4.1 – Environmental exposure tests
Environment Test method Test condition
Damp heat IEC 60793-1-50 +70 °C, 85 % RH,
30 days
Dry heat IEC 60793-1-51 +70 °C,
30 days
Change of temperature IEC 60793-1-52 T : -20 °C, T :+70 °C
a b
Table B.4.2 – Attributes measured
Attributes Unit Limits Reference
Change in optical transmission  dB/km
≤ 2
at attenuation coefficient at λ
Y
SS
nm
Tensile strength GPa at 15 % and 50 % 15 % - 0,75 3.2
Weibull Probability Levels 50 % - 0,82

These tests are normally conducted periodically as type-tests for a fibre design. Unless
otherwise indicated, the recovery period allowed between the completion of the environmental
exposure and measuring the attributes shall be as stated in the particular environmental test
method.
60793-2-20 © IEC:2007 – 13 –
Annex C
(normative)
Family specifications for A2c multimode fibres

The following clauses and tables contain the particular requirements applicable to A2c fibres.
Common requirements, repeated here for ease of reference from the sectional specification,
are noted by an entry in the “Reference” column. Relevant notes from the sectional
SS
specification are not repeated but indicated with a superscript “ ”.
C.1 Dimensional requirements
Table C.1 contains dimensional requirements specific to A2c fibres.
Table C.1 – Dimensional requirements specific to A2c fibres
Attribute Unit Limit Reference
Cladding diameter μm 280 ± 10
Core diameter
μm 200 ± 8
Core non-circularity % 3.2
≤4
Coating diameter μm [See 3.2] 3.2
Fibre length km [See 3.2] 3.2
C.2 Mechanical requirements
Table C.2 contains mechanical requirements specific to A2c fibres.
Table C.2 – Mechanical requirements specific to A2c fibres
Attribute Unit Limit Reference

SS
Proof stress level GPa 3.3
≥0,345
C.3 Transmission requirements
Table C.3 contains transmission requirements for A2c fibres.
Table C.3 – Transmission requirements specific to A2c fibres
Attribute Unit Limit Ref
SS
Attenuation coefficient at λ nm dB/km ≤10 3.3
Y
SS
Modal bandwidth at λ nm ≥10 3.3
MHz·km
Y
Theoretical numerical aperture Unitless 0,23 ± 0,03 or 3.3
0,26 ± 0,03
– 14 – 60793-2-20 © IEC:2007
C.4 Environmental requirements
Tables C.4.1 and C.4.2 contain environmental exposure tests and measurement methods
specific to A2c fibres. Test and measurements shall be documented in two forms:
• relevant environmental
...