1、 Collection of SANS standards in electronic format (PDF) 1. Copyright This standard is available to staff members of companies that have subscribed to the complete collection of SANS standards in accordance with a formal copyright agreement. This document may reside on a CENTRAL FILE SERVER or INTRA
2、NET SYSTEM only. Unless specific permission has been granted, this document MAY NOT be sent or given to staff members from other companies or organizations. Doing so would constitute a VIOLATION of SABS copyright rules. 2. Indemnity The South African Bureau of Standards accepts no liability for any
3、damage whatsoever than may result from the use of this material or the information contain therein, irrespective of the cause and quantum thereof. ICS 33.080.10 ISBN 0-626-15527-4 SANS 60793-1-54:2004 Edition 1 IEC 60793-1-54:2003 Edition 1 SOUTH AFRICAN NATIONAL STANDARD Optical fibres Part 1-54: M
4、easurement methods and test procedures Gamma irradiation This national standard is the identical implementation of IEC 60793-1-54:2003 and is adopted with the permission of the International Electrotechnical Commission. Published by Standards South Africa 1 dr lategan road groenkloof private bag x19
5、1 pretoria 0001 tel: 012 428 7911 fax: 012 344 1568 international code + 27 12 www.stansa.co.za Standards South Africa SANS 60793-1-54:2004 Edition 1 IEC 60793-1-54:2003 Edition 1 Table of changes Change No. Date Scope Abstract This standard outlines a method for measuring the steady state response
6、of optical fibres and optical cables exposed to gamma radiation. It can be employed to determine the level of radiation-induced attenuation produced in single-mode or multimode optical fibres, in either cabled or uncabled form, due to exposure to gamma radiation. It should be noted that this test is
7、 not a material test for the non-optical material components of a fibre optic cable if the degradation of cable materials exposed to irradiation is to be studied, other test methods will be required. Keywords gamma irradiation, optical cables, optical fibres. National foreword This South African sta
8、ndard was approved by National Committee StanSA SC 74A, Communication technology Fibre optics, in accordance with procedures of Standards South Africa, in compliance with annex 3 of the WTO/TBT agreement. NORMEINTERNATIONALECEIIECINTERNATIONALSTANDARD60793-1-54Premire ditionFirst edition2003-06Fibre
9、s optiques Partie 1-54:Mthodes de mesure et procdures dessai Irradiation gammaOptical fibres Part 1-54:Measurement methods and test procedures Gamma irradiationPour prix, voir catalogue en vigueurFor price, see current catalogue IEC 2003 Droits de reproduction rservs Copyright - all rights reservedA
10、ucune partie de cette publication ne peut tre reproduite niutilise sous quelque forme que ce soit et par aucun procd,lectronique ou mcanique, y compris la photocopie et lesmicrofilms, sans laccord crit de lditeur.No part of this publication may be reproduced or utilized in anyform or by any means, e
11、lectronic or mechanical, includingphotocopying and microfilm, without permission in writing fromthe publisher.International Electrotechnical Commission, 3, rue de Varemb, PO Box 131, CH-1211 Geneva 20, SwitzerlandTelephone: +41 22 919 02 11 Telefax: +41 22 919 03 00 E-mail: inmailiec.ch Web: www.iec
12、.chCODE PRIXPRICE CODE MCommission Electrotechnique InternationaleInternational Electrotechnical Commission 60793-1-54 IEC:2003 3 CONTENTSFOREWORD 5INTRODUCTION 91 Scope .112 Normative references113 Apparatus .133.1 Radiation source133.1.1 Testing of environmental background radiation 133.1.2 Testin
13、g of adverse nuclear environments .133.2 Light source.133.3 Optical filters/monochromators 133.4 Cladding mode stripper133.5 Fibre support and positioning apparatus 133.6 Optical splitter .133.7 Input launch simulator .153.7.1 Category A1 fibres (graded index multimode fibre).153.7.2 Category B fibr
14、es (single-mode fibre).153.7.3 Categories A2.1 and A2.2 (quasi-step and step index fibres) .153.8 Detector Signal detection electronics 153.9 Optical power meter.153.10 Radiation dosimeter.153.11 Temperature-controlled container 153.12 Test reel 154 Sampling and specimens 174.1 Specimens.174.1.1 Fib
15、re specimen 174.1.2 Cable specimen .174.2 Specimen for environmental background radiation test 174.3 Specimen for testing adverse nuclear environments 174.4 Test reel 174.5 Ambient light shielding.175 Procedure.175.1 Calibration of radiation source .175.2 Preparation and conditionning .195.3 Attenua
16、tion measurement for environmental background radiation.195.4 Attenuation measurement for adverse nuclear environment .216 Calculations216.1 The change in optical attenuation A (environmental backgroundradiation test) 216.2 The change in optical transmittance, A (adverse nuclear environmentalradiati
17、on test) 216.3 Normalisation of the results .237 Results .237.1 Information to be provided with each measurement .237.2 Information available upon request 238 Specification information.2560793-1-54 IEC:2003 5 INTERNATIONAL ELECTROTECHNICAL COMMISSION_OPTICAL FIBRES Part 1-54: Measurement methods and
18、 test procedures Gamma irradiationFOREWORD1) The IEC (International Electrotechnical Commission) is a worldwide organization for standardization comprisingall national electrotechnical committees (IEC National Committees). The object of the IEC is to promoteinternational co-operation on all question
19、s concerning standardization in the electrical and electronic fields. Tothis end and in addition to other activities, the IEC publishes International Standards. Their preparation isentrusted to technical committees; any IEC National Committee interested in the subject dealt with mayparticipate in th
20、is preparatory work. International, governmental and non-governmental organizations liaisingwith the IEC also participate in this preparation. The IEC collaborates closely with the InternationalOrganization for Standardization (ISO) in accordance with conditions determined by agreement between thetw
21、o organizations.2) The formal decisions or agreements of the IEC on technical matters express, as nearly as possible, aninternational consensus of opinion on the relevant subjects since each technical committee has representationfrom all interested National Committees.3) The documents produced have
22、the form of recommendations for international use and are published in the formof standards, technical specifications, technical reports or guides and they are accepted by the NationalCommittees in that sense.4) In order to promote international unification, IEC National Committees undertake to appl
23、y IEC InternationalStandards transparently to the maximum extent possible in their national and regional standards. Anydivergence between the IEC Standard and the corresponding national or regional standard shall be clearlyindicated in the latter.5) The IEC provides no marking procedure to indicate
24、its approval and cannot be rendered responsible for anyequipment declared to be in conformity with one of its standards.6) Attention is drawn to the possibility that some of the elements of this International Standard may be the subjectof patent rights. The IEC shall not be held responsible for iden
25、tifying any or all such patent rights.International Standard IEC 60793-1-54 has been prepared by subcommittee 86A: Fibres andcables, of IEC technical committee 86: Fibre optics.The text of this standard is based on the following documents:FDIS Report on voting86A/852/FDIS 86A/866/RVDFull information
26、 on the voting for the approval of this standard can be found in the report onvoting indicated in the above table.This publication has been drafted in accordance with the ISO/IEC Directives, Part 2IEC 60793-1-5X consists of the following parts, under the general title Optical fibres:Part 1-50: Measu
27、rement methods and test procedures Damp heat (steady state)Part 1-51: Measurement methods and test procedures Dry heatPart 1-52: Measurement methods and test procedures Change of temperaturePart 1-53: Measurement methods and test procedures Water immersionPart 1-54: Measurement methods and test proc
28、edures Gamma irradiation60793-1-54 IEC:2003 7 The committee has decided that the contents of this publication will remain unchanged until 2008.At this date, the publication will be reconfirmed; withdrawn; replaced by a revised edition, or amended.60793-1-54 IEC:2003 9 INTRODUCTIONPublications in the
29、 IEC 60793-1 series concern measurement methods and test proceduresas 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: Measur
30、ement methods and test procedures for mechanical characteristics parts 1-40 to 1-49: Measurement methods and test procedures for transmission andoptical characteristics parts 1-50 to 1-59: Measurement methods and test procedures for environmental characteristics60793-1-54 IEC:2003 11 OPTICAL FIBRES
31、Part 1-54: Measurement methods and test procedures Gamma irradiation1 ScopeThis part of IEC 60793 outlines a method for measuring the steady state response of opticalfibres and optical cables exposed to gamma radiation. It can be employed to determine thelevel of radiation-induced attenuation produc
32、ed in single-mode or multimode optical fibres, ineither cabled or uncabled form, due to exposure to gamma radiation.The attenuation of cabled and uncabled optical fibres generally increases when exposed togamma radiation. This is primarily due to the trapping of radiolytic electrons and holes atdefe
33、ct sites in the glass (i.e. the formation of “colour centers”). This test procedure focuses ontwo regimes of interest: the low dose rate regime suitable for estimating the effect ofenvironmental background radiation, and the high dose rate regime suitable for estimating theeffect of adverse nuclear
34、environments. The testing of the effects of environmentalbackground radiation is achieved with an attenuation measurement approach similar tomethod IEC 60793-1-40A, cut-back. The effects of adverse nuclear environments are testedby monitoring the power before, during and after exposure of the test s
35、ample to gammaradiation. The depopulation of color centers by light (photobleaching) or by heat causesrecovery (lessening of radiation induced attenuation). Recovery may occur over a wide rangeof time which depends on the irradiation time. This complicates the characterization ofradiation induced at
36、tenuation since the attenuation depends on many variables including thetemperature of the test environment, the configuration of the sample, the total dose andthe dose rate applied to the sample and the light level used to measure it.This test is not a material test for the non-optical material comp
37、onents of a fibre optic cable. Ifdegradation of cable materials exposed to irradiation is to be studied, other test methods willbe required.NOTE Background information on this subject is given in IEC/TR 622831.Attention is drawn to the fact that strict regulations and suitable protective facilities
38、areadopted in the laboratory for this test. Carefully selected trained personnel are used toperform this test. It can be extremely hazardous to test personnel if it is improperly performedor without qualified conditions.2 Normative referencesThe following referenced documents are indispensable for t
39、he application of this document.For dated references, only the edition cited applies. For undated references, the latest editionof the referenced document (including any amendments) applies.IEC 60793-1-40:2001, Optical Fibres Part 1-40: Measurement methods and test procedures AttenuationIEC 60793-1-
40、44:2001, Optical fibres Part 1-44: Measurement methods and test procedures Cut-off wavelength_1IEC 62283, Nuclear radiation Fibre optic guidance.60793-1-54 IEC:2003 13 3 Apparatus3.1 Radiation source3.1.1 Testing of environmental background radiationA 60Co or equivalent ionising source shall be used
41、 to deliver gamma radiation. This environ-ment is characterised by relative low dose and dose rate.3.1.2 Testing of adverse nuclear environmentsA 60Co or equivalent ionizing source(s) shall be used to deliver gamma radiation. Thisenvironment is characterised by higher total dose and dose rate.3.2 Li
42、ght sourceA light source such as a tungsten-halogen lamp or set of lasers or LEDs shall be used toproduce radiant energy at wavelengths of 850 nm, 1 300 nm and 1 550 nm or at wavelengthsas specified in the detail specification. The light source shall be stable in intensity over a timeperiod sufficie
43、nt to perform the measurement. The power coupled from the source into the testsample shall be 30 dBm (1,0 W) or as specified in the detail specification. The light sourceshall be modulated with a pulsed signal at a 50 % duty cycle.NOTE If a source that couples more than 1,0 W is used, photobleaching
44、 may occur.3.3 Optical filters/monochromatorsUnless otherwise specified, wavelengths of (850 20) nm, (1 300 20) nm, and(1 550 20) nm shall be obtained by filtering the light source with a set of optical filters or amonochromator. The 3 dB optical bandwidth of the filters shall be less than or equal
45、to 25 nm.3.4 Cladding mode stripperWhen necessary, a device that extracts cladding modes shall be employed at the input endand output end of the test sample. If the fibre coating materials are designed to strip claddingmodes, a cladding mode stripper is not required.3.5 Fibre support and positioning
46、 apparatusA means of stable support for the input end of the test sample such as a vacuum chuck, shallbe arranged. This support shall be mounted on a positioning device so that the end of the testsample can be repeatedly positioned in the input beam.3.6 Optical splitterAn optical splitter shall dive
47、rt a small portion of the input light to a reference detector. Thereference path shall be used to monitor system fluctuations for the duration of the test.60793-1-54 IEC:2003 15 3.7 Input launch simulator3.7.1 Category A1 fibres (graded index multimode fibre)An equilibrium mode simulator shall be us
48、ed to attenuate higher order propagation modesand to establish a steady-state mode condition near the input end of the fibre. Refer tomethod IEC 60793-1-40A for instructions on how to established proper launch conditionsfor Category A1 graded index multimode fibres.3.7.2 Category B fibres (single-mo
49、de fibre)An optical lens system or fibre pigtail may be employed to excite the test fibre. The powercoupled into the test sample shall be stable for the duration of the test. If an optical lenssystem is used, a method of making the positioning of the fibre less sensitive is to overfill thefibre end spatially and angularly. If a pigtail is used, it may be necessary to use indexmatching material to eliminate interferen
