Unknown BRITISH STANDARD BS EN 60793 1 46 2002 Optical fibres — Part 1 46 Measurement methods and test procedures — Monitoring of changes in optical transmittance The European Standard EN 60793 1 46 2[.]
BRITISH STANDARD Optical fibres — Part 1-46: Measurement methods and test procedures — Monitoring of changes in optical transmittance The European Standard EN 60793-1-46:2002 has the status of a British Standard ICS 33.180.10 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW BS EN 60793-1-46: 2002 BS EN 60793-1-46:2002 National foreword This British Standard is the official English language version of EN 60793-1-46:2002 It is identical with IEC 60793-1-46:2001 It partly supersedes BS EN 188000:1994 which will be withdrawn upon publication of the full BS EN 60793-1 series of standards The UK participation in its preparation was entrusted by Technical Committee GEL/86, Fibre optics, to Subcommittee GEL/86/1, Optical fibres and cables, which has the responsibility to: — aid enquirers to understand the text; — present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; — monitor related international and European developments and promulgate them in the UK A list of organizations represented on this subcommittee can be obtained on request to its secretary From January 1997, all IEC publications have the number 60000 added to the old number For instance, IEC 27-1 has been renumbered as IEC 60027-1 For a period of time during the change over from one numbering system to the other, publications may contain identifiers from both systems Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue A British Standard does not purport to include all the necessary provisions of a contract Users of British Standards are responsible for their correct application Compliance with a British Standard does not of itself confer immunity from legal obligations This British Standard, having been prepared under the direction of the Electrotechnical Sector Policy and Strategy Committee, was published under the authority of the Standards Policy and Strategy Committee on 23 May 2002 Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages to 12, an inside back cover and a back cover The BSI copyright date displayed in this document indicates when the document was last issued Amendments issued since publication Amd No © BSI 23 May 2002 ISBN 580 39705 X Date Comments EUROPEAN STANDARD EN 60793-1-46 NORME EUROPÉENNE EUROPÄISCHE NORM February 2002 ICS 33.180.10 Partly supersedes EN 188000:1992 English version Optical fibres Part 1-46: Measurement methods and test procedures Monitoring of changes in optical transmittance (IEC 60793-1-46:2001) Fibres optiques Partie 1-46: Méthodes de mesure et procédures d'essai Contrôle des variations du facteur de transmission optique (CEI 60793-1-46:2001) Lichtwellenleiter Teil 1-46: Messmethoden und Prüfverfahren Überwachung der optischen Übertragungsänderungen (IEC 60793-1-46:2001) This European Standard was approved by CENELEC on 2001-07-03 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-to-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 under 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, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom CENELEC European Committee for Electrotechnical Standardization Comité Européen de Normalisation Electrotechnique Europäisches Komitee für Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B - 1050 Brussels © 2002 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members Ref No EN 60793-1-46:2002 E Page EN 60793−1−46:2002 EN 69703-1-642:200 Foreword The text of document 86A/675/FDIS, future edition of IEC 60793-1-46, prepared by SC 86A, Fibres and cables, of IEC TC 86, Fibre optics, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN 60793-1-46 on 2001-07-03 This European Standard supersedes subclause 4.27 (test method 316) and subclause 4.28 (test method 317) of EN 188000:1992 The following dates were fixed: – latest date by which the EN has to be implemented at national level by publication of an identical national standard or by endorsement (dop) 2002-09-01 – latest date by which the national standards conflicting with the EN have to be withdrawn (dow) 2004-07-01 Annexes designated "normative" are part of the body of the standard In this standard, annexes A, B and ZA 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 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 EN 60793-1-XX EN 60793-2-XX Title Optical fibres Part 1-XX: Measurement methods and test procedures Optical fibres Part 2-XX: Product specifications supersedes Individual subclauses of EN 188000:1992 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 procedures – 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 - 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 – Under consideration Part 1-49: Measurement methods and test procedures – Under consideration Endorsement notice The text of the International Standard IEC 60793-1-46:2001 was approved by CENELEC as a European Standard without any modification © BSI 23 May 2002 Page EN 60793−1−46:2002 60793-1-46 © IEC:2001 –3– CONTENTS INTRODUCTION .4 Scope .5 Normative references Reference test method Apparatus 5 Sampling and specimens 6 5.1 Specimen length 5.2 Specimen end face 5.3 Specimen preparation 5.4 Reference specimen Procedure .6 Calculations Results .6 8.1 Information to be provided with each measurement 8.2 Information available upon request Specification information Annex A (normative) Requirements specific to method A – Change in transmittance by transmitted power Annex B (normative) Requirements specific to method B – Change in transmittance by backscattering 11 Annex ZA (normative) Normative references to international publications with their corresponding European publications 12 Figure A.1 – Measurement of change in optical transmittance using reference specimen Figure A.2 – Measurement of change in optical transmittance using stabilized source © BSI 23 May 2002 Page EN 60793−1−46:2002 60793-1-46 © IEC:2001 –4– 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 grouped, 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 characteristics – parts 1-40 to 1-49: Measurement methods and test procedures for transmission and optical characteristics – parts 1-50 to 1-59: Measurement methods and test procedures for environmental characteristics and test procedures for mechanical © BSI 23 May 2002 Page EN 60793−1−46:2002 60793-1-46 © IEC:2001 –5– OPTICAL FIBRES – Part 1-46: Measurement methods and test procedures – Monitoring of changes in optical transmittance Scope This part of IEC 60793 establishes uniform requirements for the monitoring of changes in optical transmittance, thereby assisting in the inspection of fibres and cables for commercial purposes This standard gives two methods for monitoring the changes in optical transmittance of optical fibres and cables that occur during mechanical or environmental testing, or both It provides a monitor in the change of optical transmission characteristics arising from optical discontinuity, physical defects and modifications of the attenuation slope: – method A: change in transmittance by transmitted power; – method B: change in transmittance by backscattering Methods A and B apply to the monitoring of all categories of the following fibres: – class A: multimode fibres; – class B: single-mode fibres Information common to both measurements is contained in clauses to 8, and information pertaining to each individual method appears in annexes A, and B respectively Normative references The following normative documents contain provisions which, through reference in this text, constitute provisions of this International Standard For dated references, subsequent amendments to, or revisions of, any of these publications not apply However, parties to agreements based on this International Standard are 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 IEC 60793-1-40, Optical fibres – Part 1-40: Measurement methods and test procedures – Attenuation Reference test method Under consideration Apparatus Annexes A and B include layout drawings and other equipment requirements that individually apply for each of the methods, respectively © BSI 23 May 2002 Page EN 60793−1−46:2002 60793-1-46 © IEC:2001 5.1 –6– Sampling and specimens Specimen length The minimum length of the specimen shall be such that the changes in attenuation are compatible with the resolution of the measurement apparatus, and the non-linearities at the beginning and end of it shall not affect the results 5.2 Specimen end face Prepare a flat end face, orthogonal to the fibre axis, at the input and output ends of each specimen 5.3 Specimen preparation Prepare the specimen as described in the appropriate mechanical, environmental, or other test method specified 5.4 Reference specimen In methods where a reference specimen is used, it shall comprise an identical kind of optical fibre or cable to the specimen and shall be linked between the optical divider and detector, as shown in figure A.1 It may be a short length of fibre The condition of the reference specimen shall be constant during the whole test Procedure For individual procedures, see annexes A and B for methods A and B, respectively Calculations For calculation procedures, see the appropriate annex: A and B, respectively 8.1 Results Information to be provided with each measurement Report the following information with each measurement: – date and title of measurement; – identification of specimen; – optical source wavelength, l; – specimen length; – conditions of the environment and measurement equipment; – changes in optical transmittance, D h ; h = 1,2,3, preferably plotted in a graph versus test parameters 8.2 Information available upon request The following information shall be available upon request: – measurement method used: A or B; – type of optical source used and its spectral width (FWHM); © BSI 23 May 2002 Page EN 60793−1−46:2002 60793-1-46 © IEC:2001 –7– – launching technique used; – description of all key equipment; – details of computation technique; – date of latest calibration of measurement equipment Specification information The detail specification shall specify the following information: – type of fibre to be measured; – failure or acceptance criteria; – information to be reported; – any deviations from the procedure that apply © BSI 23 May 2002 Page EN 60793−1−46:2002 60793-1-46 © IEC:2001 –8– Annex A (normative) Requirements specific to method A – Change in transmittance by transmitted power A.1 A.1.1 Apparatus General The arrangement shall provide a monitoring for optical transmittance with high resolution and good stability over the time and temperature changes given in the relevant product specification Figure A.1 is an example of a typical arrangement suitable for use when carrying out mechanical or environmental tests in a laboratory or factory By comparison with a reference sample, it provides a measurement of the change in optical transmittance, corrected for any changes that might occur in the optical source Connections shall have stable coupling conditions Figure A.2 is an example of a typical arrangement suitable for use in the field, laboratory or factory where long-term tests are required, in cases where it is possible to stabilize the optical source by optical feedback If the stability of the optical source is compatible with the accuracy needed for the measurement, then the insertion loss measurement method (method B of IEC 60793-1-40) may be used A.1.2 Optical source Use an suitable source such as a laser or light-emitting diode, emitting at wavelengths compatible with the optical fibres under test It is customary to modulate the optical source and wavelength selective optical filters may be used A.1.3 Optical divider The optical divider shall have a splitting ratio that remains constant during the test The splitting ratio and temperature stability shall be as shown in the relevant detail specification Commercially available or custom built devices may be used A.1.4 Optical detector The optical detector shall be of sufficient area to intercept all of the radiated power in the output cone and shall be sufficiently linear over the optical powers encountered © BSI 23 May 2002 Page EN 60793−1−46:2002 60793-1-46 © IEC:2001 –9– IEC 704/01 Figure A.1 – Measurement of change in optical transmittance using reference specimen IEC 705/01 Figure A.2 – Measurement of change in optical transmittance using stabilized source The optical detector shall have a sufficiently uniform response over the active area and range of incidence angle at the measurement wavelength to ensure the movement of the output cone in position or angle relative to the detector This shall be within the limits determined by the mechanical design of the measurement equipment and shall not significantly affect the results Where more than one detector is used, as in the arrangement shown in figure A.1, the detectors shall be of the same manufacturer and model, and be of comparable linearity A.1.5 Launch apparatus Provide apparatus to produce a full or restricted launch, depending on the parameter being measured, with conditions as shown in IEC 60793-1-40, methods A and B, for both multimode and single-mode fibre Use cladding mode strippers at the source and detector ends of the specimen, and of the reference specimen if used © BSI 23 May 2002 Page 10 EN 60793−1−46:2002 60793-1-46 © IEC:2001 A.2 – 10 – Procedure Before the test sequence, measure the initial optical power, P 0t, , from the test specimen and, in the case of figure A.1, the initial optical output power, P 0r , from the reference specimen During the test sequence specified in the appropriate mechanical, environmental, or other test being carried out, measure the subsequent optical output powers, P nt (n = 1, 2, 3, ), from the test specimen and, in the case of figure A.1, the subsequent powers, P nr , from the reference specimen In the above measurements, quantities proportional to the absolute power, rather than the absolute powers themselves, may be measured In the case of figure A.1, the proportionality factor may differ between the test and reference channels The proportionality factor(s) shall remain constant for the duration of the test sequence A.3 Calculations Calculate the changes in optical transmittance during the test sequence (in decibels) for figure 1: D n = 10 log10 P0r ´ Pnt P0t ´ Pnr (A.1) Pnt P0t (A.2) for figure 2: D n = 10 log10 where Dn is the change in optical transmittance during the sequence, in dB; P0 t is the initial optical output power from the test specimen, in mW; P0 r is the initial optical output power from the reference specimen, in mW; P nt is the subsequent optical output power from the test specimen, in mW; P nr is the subsequent optical output power from the reference specimen, in mW © BSI 23 May 2002 Page 11 EN 60793−1−46:2002 60793-1-46 © IEC:2001 – 11 – Annex B (normative) Requirements specific to method B – Change in transmittance by backscattering B.1 Apparatus See IEC 60793-1-40, method C – Backscattering B.2 B.2.1 Procedure Align the fibre under test to the coupling device B.2.2 Analyse the backscattering power by a signal processor, and record it on a logarithmic scale B.2.3 Choose two points, A and B, on the curve corresponding to the beginning and the end of the fibre or cable under test B.2.4 If necessary, make measurements from both sides B.2.5 Record the following values: – – initial power levels P A0 and P B0 at points A and B (dB); subsequent power levels P An and P Bn at points A and B (dB) B.2.6 Record the aspects of the curves for comparison before, at intervals during, and after the test sequence, as specified B.3 Calculations For smooth backscattering curves, determine the change in attenuation at the different intervals of the loss curve by the difference D n = (P A0 - P B0 ) - (P An - P Bn ) (B.1) In other cases, take care in the interpretation of the results For a more detailed interpretation of results of backscattering, see clause C.5 of IEC 60793-1-40 _ © BSI 23 May 2002 Page 12 EN 60793−1−46:2002 EN 69703-1-642:200 Annex ZA (normative) Normative references to international publications with their corresponding European publications This European Standard incorporates, by dated or undated reference, provisions from other publications These normative references are cited at the appropriate places in the text and the publications are listed hereafter For dated references, subsequent amendments to or revisions of any of these publications apply to this European Standard only when incorporated in it by amendment or revision For undated references, the latest edition of the publication referred to applies (including amendments) NOTE When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD applies Publication Year IEC 60793-1-40 - 1) 2) 1) Title EN/HD Year Optical fibres Part 1-40: Measurement methods and test procedures - Attenuation EN 60793-1-40 - 2) Undated reference To be published © BSI 23 May 2002 BS EN 60793-1-46: 2002 BSI — British Standards Institution BSI is the independent national body responsible for preparing British Standards It presents the UK view on standards in Europe and at the international level It is incorporated by Royal Charter Revisions British Standards are updated by 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