1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationOptical fibresPart 1-54: Measurement methods and test procedures Gamma irradiationBS EN 60793-1-54:2013National forewordThis British Standard is the UK implementation of EN 60793
2、-1-54:2013. It is identical to IEC 60793-1-54:2012. It supersedes BS EN 60793-1-54:2003,which is withdrawn.The UK participation in its preparation was entrusted by Technical Committee GEL/86, Fibre optics, to Subcommittee GEL/86/1, Optical fibres and cables.A list of organizations represented on thi
3、s committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. The British Standards Institution 2013.Published by BSI Standards Limited 2013.ISBN 978 0 580 74104 3 IC
4、S 33.180.10Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 April 2013.Amendments issued since publicationDate Text affectedBRITISH STANDARDBS EN 60793-1-54:20
5、13EUROPEAN STANDARD EN 60793-1-54 NORME EUROPENNE EUROPISCHE NORM January 2013 CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Management Centre: Avenue Marnix 17, B - 1000 Brussels 2013
6、CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 60793-1-54:2013 E ICS 33.180.10 Supersedes EN 60793-1-54:2003 English version Optical fibres - Part 1-54: Measurement methods and test procedures - Gamma irradiation (IEC 60793-1-54:
7、2012) Fibres optiques - Partie 1-54: Mthodes de mesure et procdures dessai - Irradiation gamma (CEI 60793-1-54:2012) Lichtwellenleiter - Teil 1-54: Messmethoden und Prfverfahren - Radioaktive Strahlung (IEC 60793-1-54:2012) This European Standard was approved by CENELEC on 2012-11-29. CENELEC member
8、s 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
9、 to the CEN-CENELEC Management Centre 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 CEN-CENELEC M
10、anagement Centre has the same status as the official versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland,
11、 Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. BS EN 60793-1-54:2013EN 60793-1-54:2013 Foreword The text of document 86A/1413/CDV, future edition 2 of IEC 60793-
12、1-54, prepared by SC 86A “Fibresand cables“ of IEC/TC 86 “Fibre optics“ was submitted to the IEC-CENELEC parallel vote andapproved by CENELEC as EN 60793-1-54:2013. The following dates are fixed: latest date by which the document has to be implemented at national level bypublication of an identical
13、nationalstandard or by endorsement (dop) 2013-08-29 latest date by which the national standards conflicting with the document have to be withdrawn (dow) 2015-11-29 This document supersedes EN 60793-1-54:2003. EN 60793-1-54:2013 includes the following significant technical changes with respect toEN 6
14、0793-1-54:2003: - launching conditions and optical sources have been reviewed and are better defined. Attention is drawn to the possibility that some of the elements of this document may be the subject ofpatent rights. CENELEC and/or CEN shall not be held responsible for identifying any or all suchp
15、atent rights. Endorsement notice The text of the International Standard IEC 60793-1-54:2012 was approved by CENELEC as aEuropean Standard without any modification. In the official version, for Bibliography, the following notes have to be added for the standards indicated: IEC 60793-2-10 NOTE Harmoni
16、sed as EN 60793-2-10. IEC 60793-2-20 NOTE Harmonised as EN 60793-2-20. IEC 60793-2-50 NOTE Harmonised as EN 60793-2-50. BS EN 60793-1-54:2013EN 60793-1-54:2013 Annex ZA (normative) Normative references to international publicationswith their corresponding European publications The following document
17、s, in whole or in part, are normatively referenced in this document and areindispensable for its application. For dated references, only the edition cited applies. For undatedreferences, the latest edition of the referenced document (including any amendments) applies. NOTE When an international publ
18、ication has been modified by common modifications, indicated by (mod), the relevant EN/HDapplies. Publication Year Title EN/HD Year IEC 60793-1-40 - Optical fibres - Part 1-40: Measurement methods and test procedures - Attenuation EN 60793-1-40 - IEC 60793-1-44 - Optical fibres - Part 1-44: Measurem
19、ent methods and test procedures - Cut-off wavelength EN 60793-1-44 - IEC 60793-1-46 - Optical fibres - Part 1-46: Measurement methods and test procedures - Monitoring of changes in optical transmittance EN 60793-1-46 - IEC 61280-4-1 - Fibre optic communication subsystem testprocedures - Part 4-1: In
20、stalled cable plant - Multimode attenuation measurement EN 61280-4-1 - BS EN 60793-1-54:201360793-1-54 IEC:2012(E) CONTENTS 1 Scope . . 5 2 Normative references . 5 3 Apparatus . 6 Radiation source . 6 3.1Testing of environmental background radiation . 6 3.1.1Testing of adverse nuclear environments
21、. 6 3.1.2 Optical source . 6 3.2Optical filters/monochromators . 6 3.3Cladding mode stripper 6 3.4Fibre support and positioning apparatus 6 3.5Optical splitter . 6 3.6Input launch conditions . 7 3.7Class A, category A1 fibres (graded index multimode fibres) . 7 3.7.1Class B fibres (single-mode fibre
22、s) . 7 3.7.2Class A, category A2 fibres (quasi-step and step index fibres) . 7 3.7.3 Detector Signal detection electronics 7 3.8Optical power meter . 7 3.9Radiation dosimeter . 7 3.10Temperature controlled container . 7 3.11Test reel 7 3.124 Sampling and specimens 7 Specimens . 7 4.1Fibre specimen .
23、 7 4.1.1Cable specimen 8 4.1.2 Specimen for environmental background radiation test . 8 4.2Specimen for testing adverse nuclear environments . 8 4.3Test reel 8 4.4Ambient light shielding . 8 4.55 Procedure. 8 General . 8 5.1Calibration of radiation source . . 8 5.2Preparation and pre-conditioning 8
24、5.3Attenuation measurement for environmental background radiation . . 9 5.4Attenuation measurement for adverse nuclear environment . 9 5.56 Calculations . 10 Change in optical attenuation a (environmental background radiation test) . . 10 6.1Change in optical transmittance, a (adverse nuclear enviro
25、nmental radiation 6.2test) . . 10 Normalization of the results . 10 6.37 Results 11 Information to be provided with each measurement . . 11 7.1Information available upon request . . 11 7.28 Specification information . 11 Bibliography . 12 BS EN 60793-1-54:201360793-1-54 IEC:2012(E) 5 OPTICAL FIBRES
26、Part 1-54: Measurement methods and test procedures Gamma irradiation1 Scope This part of IEC 60793 outlines a method for measuring the steady state response of optical fibres and optical cables exposed to gamma radiation. It can be employed to determine the level of radiation induced attenuation pro
27、duced in Class B single-mode or Class A, category A1 and A2 multimode optical fibres, in either cabled or uncabled form, due to exposure to gamma radiation. The attenuation of cabled and uncabled optical fibres generally increases when exposed to gamma radiation. This is primarily due to the trappin
28、g of radiolytic electrons and holes at defect sites in the glass (i.e. the formation of “colour centres”). This test procedure focuses on two regimes of interest: the low dose rate regime suitable for estimating the effect of environmental background radiation, and the high dose rate regime suitable
29、 for estimating the effect of adverse nuclear environments. The testing of the effects of environmental background radiation is achieved with an attenuation measurement approach similar to IEC 60793-1-40 Method A, cut-back. The effects of adverse nuclear environments are tested by monitoring the pow
30、er before, during and after exposure of the test sample to gamma radiation. The depopulation of colour centres by light (photo bleaching) or by heat causes recovery (lessening of radiation induced attenuation). Recovery may occur over a wide range of time which depends on the irradiation time and an
31、nealing temperature. This complicates the characterization of radiation induced attenuation since the attenuation depends on many variables including the temperature of the test environment, the configuration of the sample, the total dose and the dose rate applied to the sample and the light level u
32、sed to measure it. This test is not a material test for the non-optical material components of a fibre optic cable. If degradation of cable materials exposed to irradiation is to be studied, other test methods will be required. This test method is written to contain a clear, concise listing of instr
33、uctions. The background knowledge that is necessary to perform correct, relevant and expressive irradiation tests as well as to limit measurement uncertainty is presented separately in IEC/TR 62283. Attention is drawn to the fact that strict regulations and suitable protective facilities are to be a
34、dopted in the laboratory for this test. Carefully selected trained personnel shall be used to perform this test. It can be extremely hazardous to test personnel if it is improperly performed or without qualified conditions. 2 Normative references The following documents, in whole or in part, are nor
35、matively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. IEC 60793-1-40, Optical Fibres Part 1-40: Measurement method
36、s and test procedures Attenuation IEC 60793-1-44, Optical fibres Part 1-44: Measurement methods and test procedures Cut-off wavelength BS EN 60793-1-54:2013 6 60793-1-54 IEC:2012(E) IEC 60793-1-46, Optical fibres Part 1-46: Measurement methods and test procedures Monitoring of changes in optical tra
37、nsmittance IEC 61280-4-1, Fibre-optic communication subsystem test procedures Part 4-1: Installed cable plant Multimode attenuation measurement 3 Apparatus Radiation source 3.1Testing of environmental background radiation 3.1.1A 60Co or equivalent ionising source shall be used to deliver gamma radia
38、tion. This environment is characterised by relatively low total dose and dose rate. Testing of adverse nuclear environments 3.1.2A 60Co or equivalent ionizing source(s) shall be used to deliver gamma radiation. This environment is characterised by higher total dose and dose rate. Optical source 3.2A
39、n optical source such as a lamp, laser or light emitting diode emitting at wavelengths compatible with the optical fibres under test shall be used. The optical source shall be stable in intensity over a time period sufficient to perform the measurement. The power coupled from the source into the tes
40、t sample shall be 30 dBm (1,0 W) or as specified in the detail specification. The optical source shall be modulated with a pulsed signal at a 50 % duty cycle. NOTE If a source that couples more than 1,0 W is used, photo bleaching may occur. Optical filters/monochromators 3.3Unless otherwise specifie
41、d, wavelength tolerances of 20 nm shall be obtained by filtering the optical source with a set of optical filters or a monochromator. The 3 dB optical bandwidth of the filters shall be less than or equal to 25 nm. Cladding mode stripper 3.4When necessary, a device that extracts cladding modes shall
42、be employed at the input end and output end of the test sample. If the fibre coating materials are designed to strip cladding modes, a cladding mode stripper is not required. Fibre support and positioning apparatus 3.5A means of stable support for the input end of the test sample, such as a vacuum c
43、huck, shall be arranged. This support shall be mounted on a positioning device so that the end of the test sample can be repeatedly positioned in the input beam. Optical splitter 3.6An optical splitter shall divert a small portion of the input light to a reference detector. The reference path shall
44、be used to monitor system fluctuations for the duration of the test. BS EN 60793-1-54:201360793-1-54 IEC:2012(E) 7 Input launch conditions 3.7Class A, category A1 fibres (graded index multimode fibres) 3.7.1An equilibrium mode simulator shall be used to attenuate higher order propagation modes and t
45、o establish a steady-state mode condition near the input end of the fibre. The requirements for the launch conditions for sub-category A1a graded index multimode fibre measurements are defined in IEC 61280-4-1. Class B fibres (single-mode fibres) 3.7.2An optical lens system or fibre pigtail may be e
46、mployed to excite the test fibre. The power coupled into the test sample shall be stable for the duration of the test. If an optical lens system is used, a method of making the positioning of the fibre less sensitive is to overfill the fibre end spatially and angularly. If a pigtail is used, it may
47、be necessary to use index matching material to eliminate interference effects. A high order mode filter shall be employed to remove high order propagating modes in the wavelength range greater than or equal to the cut-off wavelength of the test fibre. The test condition specified in IEC 60793-1-44,
48、Method C satisfies this requirement. Class A, category A2 fibres (quasi-step and step index fibres) 3.7.3Launch conditions shall be created as specified in the detail specification. Detector Signal detection electronics 3.8An optical detector which is linear and stable over the range of intensities
49、that are encountered shall be used. A typical system might include a photovoltaic mode photodiode amplified by a current input preamplifier, with synchronous detection by a lock-up amplifier. Optical power meter 3.9A suitable optical power meter shall be used to determine that the power coupled from the optical source into the test sample is less than or equal to 1,0 W or the level specified in the detail specification. Radiation dosimeter 3.10Thermo luminescent LiF or CaF crystal detectors (TLDs) or an ion cham
