1、BRITISH STANDARD BS EN 60793-1-40: 2003 Optical fibres Part 1-40: Measurement methods and test procedures Attenuation The European Standard EN 60793-1-40:2003 has the status of a British Standard ICS 33.180.10 BS EN 60793-1-40:2003 This British Standard was published under the authority of the Stand
2、ards Policy and Strategy Committee on 6 February 2004 BSI 6 February 2004 ISBN 0 580 43350 1 National foreword This British Standard is the official English language version of EN 60793-1-40:2003. It was derived by CENELEC from IEC 60793-1-40:2001. It partially supersedes BS EN 188000:1994 which wil
3、l be withdrawn on publication of the full BS EN 60793-1 series. The CENELEC common modifications have been implemented at the appropriate places in the text and are indicated by tags (). The UK participation in its preparation was entrusted by Technical Committee GEL/86, Fibre optics, to Subcommitte
4、e GEL/86/1, Optical fibres and cables, which has the responsibility to: A list of organizations represented on this subcommittee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may
5、 be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online. This publication does not purport to include all the necessary provisions of a contract. Users a
6、re responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, an
7、d keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 31 and a back cover. The BSI copyright notice displayed in this docume
8、nt indicates when the document was last issued. Amendments issued since publication Amd. No. Date CommentsEUROPEAN STANDARD EN 60793-1-40 NORME EUROPENNE EUROPISCHE NORM December 2003 CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Euro
9、pisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B - 1050 Brussels 2003 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 60793-1-40:2003 E ICS 33.180.10 Partly supersedes EN 188000:1992English v
10、ersion Optical fibres Part 1-40: Measurement methods and test procedures Attenuation (IEC 60793-1-40:2001, modified) Fibres optiques Partie 1-40: Mthodes de mesure et procdures dessai Affaiblissement (CEI 60793-1-40:2001, modifie) Lichtwellenleiter Teil 1-40: Messmethoden und Prfverfahren Dmpfung (I
11、EC 60793-1-40:2001, modifiziert) This European Standard was approved by CENELEC on 2003-11-01. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-t
12、o-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CENELEC member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation u
13、nder the responsibility of a CENELEC member into its own language and notified to the Central Secretariat has the same status as the official versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary
14、, Iceland, Ireland, Italy, Lithuania, Luxembourg, Malta, Netherlands, Norway, Portugal, Slovakia, Spain, Sweden, Switzerland and United Kingdom. Foreword The text of document 86A/669/FDIS, future edition 1 of IEC 60793-1-40, prepared by SC 86A, Fibres and cables, of IEC TC 86, Fibre optics, was subm
15、itted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN 60793-1-40 on 2001-10-01. A draft amendment, prepared by the Technical Committee CENELEC CENELEC TC 86A, Optical fibres and optical fibre cables, was submitted to the Unique Acceptance Procedure and was approved by CENELEC for
16、inclusion into EN 60793-1-40 on 2003-11-01. This European Standard supersedes subclause 4.5 (test method 301), subclause 4.6 (test method 302) and subclause 4.7 (test method 303) of EN 188000:1992. The following dates were fixed: latest date by which the EN has to be implemented at national level by
17、 publication of an identical national standard or by endorsement (dop) 2004-11-01 latest date by which the national standards conflicting with the EN have to be withdrawn (dow) 2006-11-01 Annexes designated “normative“ are part of the body of the standard. In this standard, Annexes A, B, C, D and ZA
18、 are normative. Annex ZA has been added by CENELEC. Compared to IEC 60793-1:1989 and IEC 60793-2:1992, IEC/SC 86A has adopted a revised structure of the new IEC 60793 series: The individual measurement methods and test procedures for optical fibres are published as “Part 1-XX“; the product standards
19、 are published as “Part 2-XX“. The general relationship between the new series of EN 60793 and the superseded European Standards of the EN 188000 series is as follows: EN Title supersedes EN 60793-1-XX Optical fibres - Part 1-XX: Measurement methods and test procedures Individual subclauses of EN 18
20、8000:1992 EN 60793-2-XX Optical fibres - Part 2-XX: Product specifications EN 188100:1995 EN 188101:1995 EN 188102:1995 EN 188200:1995 EN 188201:1995 EN 188202:1995 EN 60793-1-4X consists of the following parts, under the general title: Optical fibres: - Part 1-40: Measurement methods and test proce
21、dures Attenuation - Part 1-41: Measurement methods and test procedures Bandwidth - Part 1-42: Measurement methods and test procedures Chromatic dispersion - Part 1-43: Measurement methods and test procedures Numerical aperture - Part 1-44: Measurement methods and test procedures Cut-off wavelength -
22、 Part 1-45: Measurement methods and test procedures Mode field diameter - Part 1-46: Measurement methods and test procedures Monitoring of changes in optical transmittance - Part 1-47: Measurement methods and test procedures Macrobending loss - Part 1-48: Measurement methods and test procedures Pola
23、rization mode dispersion - Part 1-49: Measurement methods and test procedures Differential mode delay _ Page2 EN60793140:2003Endorsement notice The text of the International Standard IEC 60793-1-40:2001 was approved by CENELEC as a European Standard with agreed common modifications. Page3 EN60793140
24、:2003 CONTENTS INTRODUCTION.6 1 Scope 7 2 Normative references.7 3 Definitions8 4 Calibration requirements 9 5 Reference test method .9 6 Apparatus 9 7 Sampling and specimens9 7.1 Specimen length9 7.2 Specimen end face9 8 Procedure 9 9 Calculations .9 9.1 Methods A and B .9 9.2 Method C10 9.3 Method
25、 D10 10 Results .10 10.1 Information available with each measurement .10 10.2 Information available upon request .10 11 Specification information .10 Annex A (normative) Requirements specific to method A Cut-back 11 Annex B (normative) Requirements specific to method B Insertion loss18 Annex C (norm
26、ative) Requirements specific to method C Backscattering .19 Annex D (normative) Requirements specific to method D .29 Annex ZA (normative) Normative references to international publications with their corresponding European publication.31 Figure A.1 Arrangement of equipment to make loss measurement
27、at one specified wavelength11 Figure A.2 Arrangement of equipment used to obtain loss spectrum .12 Figure A.3 General launch arrangement .13 Figure A.4 Limited phase space launch optics 16 Figure A.5 Lens system17 Figure A.6 Launch fibre 17 Figure A.7 Mode scrambler (for A4 fibre) 17 Figure B.1 Cali
28、bration of insertion loss measurement set19 Figure B.2 Measurement of insertion loss .19 Figure C.1 Block diagram of an OTDR20 Page4 EN60793140:2003 Figure C.2 Schematic OTDR trace for a “uniform“ specimen preceded by a dead-zone fibre23 Figure C.3 Schematic OTDR trace for a “uniform“ specimen not p
29、receded by a dead-zone fibre23 Figure C.4 Schematic OTDR trace showing apparent loss due to point discontinuities, one reflective and one non-reflective25 Figure C.5 Schematic of an expanded OTDR trace showing two point discontinuities, one with apparent gain, and another with no apparent loss or ga
30、in .26 Table A.1 Mandrel sizes examples 15 Table A.2 Launch conditions for A2 to A4 fibres16 Page5 EN60793140:2003 INTRODUCTION Publications in the IEC 60793-1 series concern measurement methods and test procedures as they apply to optical fibres. Within the same series several different areas are g
31、rouped, as follows: parts 1-10 to 1-19: General parts 1-20 to 1-29: Measurement methods and test procedures for dimensions parts 1-30 to 1-39: Measurement methods and test procedures for mechanical charac- teristics parts 1-40 to 1-49: Measurement methods and test procedures for transmission and opt
32、ical characteristics parts 1-50 to 1-59: Measurement methods and test procedures for environmental charac- teristics. Page6 EN60793140:2003 OPTICAL FIBRES Part 1-40: Measurement methods and test procedures Attenuation 1 Scope This part of IEC 60793 establishes uniform requirements for measuring the
33、attenuation of optical fibre, thereby assisting in the inspection of fibres and cables for commercial purposes. Four methods are described for measuring attenuation, one of which being that for modelling spectral attenuation: method A: cut-back; method B: insertion loss; method C: backscattering; me
34、thod D: modelling spectral attenuation. Methods A to C apply to the measurement of attenuation for all categories of the following fibres: class A multimode fibres; class B single-mode fibres. Method C, backscattering, also covers the location, losses and characterization of point discontinuities. T
35、o date, method D has been demonstrated only on class B fibres. Information common to all three measurements, and to the modelling method, appears in clauses 1 to 8, and information pertaining to each individual method appears in annexes A, B, C, and D, respectively. 2 Normative references The follow
36、ing normative documents contain provisions which, through reference in this text, constitute provisions of this part of IEC 60793. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this part of IEC 60793 a
37、re encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. Members of IEC and ISO maintain registers of currently valid International Standards
38、. IEC 60793-1-22, Optical fibres Part 1-22: Measurement methods and test procedures Length IEC 60793-1-43, Optical fibres Part 1-43: Measurement methods and test procedures Numerical aperture Page7 EN60793140:2003 3 Definitions For the purpose of this part of IEC 60793, the following definitions app
39、ly. NOTE Attenuation is a measure of the decreasing optical power in a fibre at a given wavelength. It depends on the nature and length of the fibre and is also affected by measurement conditions. Uncontrolled launching conditions normally excite higher order lossy modes that produce transient losse
40、s and result in attenuation that is not proportional to the length of the fibre. A controlled, steady-state launching condition yields attenuation that is proportional to the fibres length. Under steady-state conditions, an attenuation coefficient of a fibre can be determined and the attenuation of
41、concatenated fibres added linearly. 3.1 attenuation attenuation of a fibre at wavelength between two cross-sections, 1 and 2, separated by a distance and defined as A () = | 10 log 10) ( ) ( 2 1 P P| (1) where A() is the attenuation, in dB, at wavelength ; P 1 () is the optical power traversing cros
42、s-section 1; P 2 () is the optical power traversing cross-section 2. 3.2 attenuation coefficient attenuation per unit length for a uniform fibre under steady state conditions, it is possible to define the attenuation per unit length or the attenuation coefficient as follows: L A ) ( ) ( =(2) which i
43、s independent of the chosen length of the fibre; where () is the attenuation coefficient; A() is the attenuation at wavelength ; L is the length, in kilometres. 3.3 spectral attenuation modelling technique that predicts the attenuation coefficients across a spectrum of wavelengths from a small numbe
44、r (three to five) of discrete values measured directly 3.4 point discontinuities temporary or permanent local deviation of the continuous OTDR signal in the upward or downward direction NOTE The nature of the deviation can vary with test conditions (e.g. pulse duration, wavelength, and direction of
45、the OTDR signal). Although a point discontinuity can have a length greater than the corresponding displayed pulse duration (including transmitter and receiver effects), the length is usually about equal to the pulse duration. For a correct interpretation, the guidelines in IEC 60793-1-22 should be f
46、ollowed for measuring length. Page8 EN60793140:2003 4 Calibration requirements Under consideration. 5 Reference test method Method A, cut-back, is the reference test method (RTM), which shall be the one used to settle disputes. 6 Apparatus Annexes A, B, C, and D include layout drawings and other equ
47、ipment requirements for each of the methods, respectively. 7 Sampling and specimens 7.1 Specimen length The specimen shall be a known length of fibre on a reel, or within a cable, as specified in the detail specification. 7.2 Specimen end face Prepare a flat end face, orthogonal to the fibre axis, a
48、t the input and output ends of each specimen. 8 Procedure See annexes A, B, C and D for methods A, B, C and D, respectively. 9 Calculations 9.1 Methods A and B Methods A and B, cut-back and insertion loss, respectively, use equations (1) and (2), which appear in 3.1 and 3.2. Page9 EN60793140:2003 9.
49、2 Method C See annex C. 9.3 Method D See annex D. 10 Results 10.1 Information available with each measurement Report the following information with each measurement: date and title of measurement; identification of specimen; optical source wavelength; specimen length; spectral attenuation, dB, or attenuation coefficient, dB
