《BS-IEC-61745-1998.pdf》由会员分享,可在线阅读,更多相关《BS-IEC-61745-1998.pdf(34页珍藏版)》请在三一文库上搜索。
1、BRITISH STANDARD BS IEC 61745:1998 End-face image analysis procedure for the calibration of optical fibre geometry test sets ICS 33.180.01 Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 12:04:36 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS IEC 61745:1998 This British Standard, having been p
2、repared under the direction of the Electrotechnical Sector Committee, was published under the authority of the Standards Committee and comes into effect on 15 April 1999 BSI 03-2000 ISBN 0 580 32359 5 National foreword This British Standard reproduces verbatim IEC 61745:1998 and implements it as the
3、 UK national standard. The UK participation in its preparation was entrusted to Technical Committee GEL/86, Fibre optics, which has the responsibility to: aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposa
4、ls 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 committee can be obtained on request to its secretary. From 1 January 1997, all IEC publications have the number 60000
5、 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 Eur
6、opean 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 nec
7、essary 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. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, the
8、IEC title page, pages ii to iv, pages 1 to 25 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Amendments issued since publication Amd. No.DateComments Licensed Cop
9、y: sheffieldun sheffieldun, na, Sun Nov 26 12:04:36 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS IEC 61745:1998 BSI 03-2000i Contents Page National forewordInside front cover Forewordiii Text of IEC 617451 Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 12:04:36 GMT+00:00 2006, Uncontrolled
10、Copy, (c) BSI ii blank Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 12:04:36 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 12:04:36 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS IEC 61745:1998 ii BSI 03-2000 Contents Page Forewordiii 1Gen
11、eral1 1.1Scope and object1 1.2Definitions1 1.3Geometrical parameters of optical fibres4 1.4Description of geometry test sets4 1.5Calibration standard requirements4 2Calibration4 2.1Introductory remark4 2.2Rationale for calibration of geometry test sets4 2.3Calibration procedure5 2.4Check calibration
12、 procedure7 2.5Spatial linearity8 2.6Calibration of core/cladding concentricity error measurement8 2.7Calibration of non-circularity measurement8 3Evaluation of uncertainties8 3.1Introductory remark8 3.2Evaluation of uncertainty in test set calibration8 3.3Evaluation of uncertainty in fibre measurem
13、ent10 3.4Evaluation of uncertainty in chromium mask measurement11 3.5Summary11 4Documentation11 4.1Records11 4.2Certificate of calibration12 4.3Sample calibration certificate13 Annex A (informative) Derivation of calibration factors15 Annex B (informative) Worked examples for the determination of ca
14、libration factors17 Annex C (normative) Calculation of uncertainties18 Annex D (informative) Worked examples for the determination of uncertainties20 Annex E (informative) Generation of working standards22 Annex F (informative) Estimation of uncertainty in the measurement of core/cladding concentric
15、ity error22 Annex G (informative) Estimation of uncertainty in the measurement of non-circularity24 Figure 1 Example of a calibration chain and the accumulation of uncertainties14 Figure A.1 Representation of a grid calibration mask16 Figure A.2 Representation of an annulus calibration mask16 Figure
16、 A.3 Derivation of correction offset17 Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 12:04:36 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS IEC 61745:1998 BSI 03-2000iii Foreword 1) The IEC (International Electrotechnical Commission) is a worldwide organization for standardization comprisin
17、g all national electrotechnical committees (IEC National Committees). The object of the 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, the IEC publishes International S
18、tandards. 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. The I
19、EC collaborates closely with the International Organization for Standardization (ISO) in accordance with conditions determined by agreement between the two organizations. 2) The formal decisions or agreements of the IEC on technical matters express, as nearly as possible, an international consensus
20、of opinion on the relevant subjects since each technical committee has representation from all interested National Committees. 3) The documents produced have the form of recommendations for international use and are published in the form of standards, technical reports or guides and they are accepte
21、d by the National Committees in that sense. 4) In order to promote international unification, IEC National Committees undertake to apply IEC International Standards transparently to the maximum extent possible in their national and regional standards. Any divergence between the IEC Standard and the
22、corresponding national or regional standard shall be clearly indicated in the latter. 5) The IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any equipment declared to be in conformity with one of its standards. 6) Attention is drawn to the possibilit
23、y that some of the elements of this International Standard may be the subject of patent rights. The IEC shall not be held responsible for identifying any or all such patent rights. International Standard IEC 61745 has been prepared by IEC technical committee 86: Fibre optics. The text of this standa
24、rd is based on the following documents: Full information on the voting for the approval of this standard can be found in the report on voting indicated in the above table. Annex C forms an integral part of this standard. Annex A, Annex B, Annex D, Annex E, Annex F and Annex G are for information onl
25、y. A bilingual version of this standard may be issued at a later date. FDISReport on voting 86/125/FDIS86/134/RVD Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 12:04:36 GMT+00:00 2006, Uncontrolled Copy, (c) BSI iv blank Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 12:04:36 GMT+00
26、:00 2006, Uncontrolled Copy, (c) BSI BS IEC 61745:1998 BSI 03-20001 1 General 1.1 Scope and object In the research and production environments there exists a range of test methods for characterizing the geometry of optical fibres. Furthermore, each test method may determine one or more of the many p
27、arameters required for complete geometrical characterization. This International Standard describes the calibration of test sets which perform end-face image analysis, also known as near-field or grey-scale analysis. The principles, however, may be applied to test sets of a different type. This stan
28、dard addresses the calibration of measurements made on single-mode fibres only; however, this type of test set may also be used to measure the geometrical parameters of the cores of multimode fibres, but the evaluation of uncertainties associated with these measurements is beyond the scope of this s
29、tandard. The procedures outlined are to be performed by calibration laboratories and by the manufacturers or users of geometry test sets, for the purpose of calibrating geometry test sets and for evaluating the uncertainties in measurements made on calibrated test sets. The calibration of fibre coat
30、ing or cable measurement test sets is not covered by this standard. The object of this standard is to define a standard procedure for the calibration of test sets for measuring the glass geometry of optical fibres. 1.2 Definitions For the purpose of this International Standard, the following definit
31、ions apply. 1.2.1 accredited calibration laboratory calibration laboratory authorised by the appropriate National Standards laboratory to issue calibration certificates with a specified uncertainty, which demonstrate traceability to national standards 1.2.2 artefact any object that is measured on or
32、 used to calibrate a geometry test set. An artefact may be, for example, an optical fibre or a chromium-on-glass pattern 1.2.3 calibration process by which the relationship between the values indicated by the geometry test set under calibration and the known values of the calibration standard is est
33、ablished. The purpose of calibration is to bring all geometry test sets into substantial agreement with a national standards laboratory. This may be performed either by adjustment of the geometry test set or by documentation of a calibration factor(s) in a calibration certificate. The pertaining env
34、ironment and instrument conditions at the time of calibration are usually recorded. Calibration includes estimation of all uncertainties 1.2.4 calibration chain chain of transfers from a national standard to the geometry test set through intermediate or working standards (see Figure 1) 1.2.5 calibra
35、tion checking establishing that a geometry test set that has been previously calibrated but has reached its calibration due date remains within specified uncertainty limits. If the geometry test set has drifted outside these limits, then re-calibration is required. Otherwise, the re-checking period
36、can be extended for a stated period. The test set may be checked using a working standard 1.2.6 calibration standard artefact that is calibrated against a reference standard and is used to calibrate test sets. The artefact may be a fibre or a chromium-on-glass pattern. Proper use of a calibration st
37、andard ensures traceability. The term includes the reference standard, the transfer standard and the working standard(s), in descending order of metrological uncertainty Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 12:04:36 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS IEC 61745:1998 2 BSI
38、 03-2000 1.2.7 combined standard uncertainty combination of a number of individual standard uncertainties the term “accuracy” should be avoided in this context in calibration reports and technical data sheets, the combined standard uncertainty in the geometry test set measurement is reported as an o
39、verall expanded uncertainty with the applicable confidence level, for example 95,5 % or 99,7 % 1.2.8 confidence level estimation of the probability that the true value of a measured parameter lies within a given range (expanded uncertainty) 1.2.9 correction offset number that is added to or subtract
40、ed from the measurement result of a test set to correct for a known physical effect 1.2.10 coverage factor, k factor used to calculate the expanded uncertainty U from the standard uncertainty 1.2.11 expanded uncertainty, U range of values within which the true value of the measured parameter, at the
41、 stated confidence level, can be expected to lie. It is also called the confidence interval and is equal to the coverage factor k times the standard uncertainty u: U = k u the measurement uncertainty of a geometry test set should be specified in the form of expanded uncertainty NOTEWhen the distribu
42、tion of uncertainties is assumed to be normal and a large number of measurements are made, then confidence levels of 68,3 %, 95,5 % and 99,7 % correspond to values for k of 1, 2, and 3 respectively (see clause C.3). 1.2.12 geometry test set instrument used to measure the geometrical parameters of an
43、 optical fibre. The parameters measured will depend on the type of geometry test set 1.2.13 infant fibre fibre whose geometry is to be measured on a calibrated geometry test set 1.2.14 instrument state description of the measurement conditions of the geometry test set during calibration and measurem
44、ent, for instance form-fits used, data filtering schemes employed and other important information concerning the test set such as warm-up time and date of calibration 1.2.15 national standard standard whose measurement is traceable to fundamental quantities, such as the wavelength of light, and whic
45、h is used as the basis for fixing the value, in a country, of all other standards of the quantity concerned 1.2.16 national standards laboratory body or laboratory that maintains and operates the national standard Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 12:04:36 GMT+00:00 2006, Uncont
46、rolled Copy, (c) BSI BS IEC 61745:1998 BSI 03-20003 1.2.17 operating range range of conditions under which the geometry test set is designed to perform within the stated expanded uncertainty; for example diameter of the fibre being measured and environmental conditions, such as temperature 1.2.18 re
47、ference standard artefact measured at a calibration laboratory, with the measurement traceable to national standards 1.2.19 scaling factor ratio of the known standard values for a calibration standard to the values indicated by the geometry test set when no correction offsets are applied 1.2.20 stan
48、dard uncertainty standard uncertainty may be evaluated either by statistical methods, termed type A evaluation, or by other means, termed type B evaluation (see Annex C for a more detailed description) a type A evaluation of uncertainty consists of a statistical analysis of a series of measurements,
49、 such as when evaluating certain random effects of measurement a type B evaluation of uncertainty is used when a statistical analysis is not appropriate. It consists of an estimation of the probable sources of uncertainty, such as when evaluating certain systematic effects of measurement NOTEIn order to combine standard uncertainties from different sources it is important that they all be stated at the same confidence level. This may be achieved by use of the coverage factor k, which is determined with reference to Students t distribution for each individual unce
链接地址:https://www.31doc.com/p-3748310.html