1、BSI Standards PublicationSuperconductivityPart 4: Residual resistance ratio measurement Residual resistance ratio of Nb-Ti and Nb3Sn composite superconductorsBS EN 61788-4:2016National forewordThis British Standard is the UK implementation of EN 61788-4:2016. It isidentical to IEC 61788-4:2016. It s
2、upersedes BS EN 61788-4:2011 which iswithdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee L/-/90, Super Conductivity.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the
3、necessary provisions ofa contract. Users are responsible for its correct application. The British Standards Institution 2016.Published by BSI Standards Limited 2016ISBN 978 0 580 86604 3ICS 17.200.20; 29.050Compliance with a British Standard cannot confer immunity fromlegal obligations.This British
4、Standard was published under the authority of theStandards Policy and Strategy Committee on 30 April 2016.Amendments/corrigenda issued since publicationDate Text affectedBRITISH STANDARDBS EN 61788-4:2016EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 61788-4 April 2016 ICS 17.200.20; 29.050 Su
5、persedes EN 61788-4:2011 English Version Superconductivity - Part 4: Residual resistance ratio measurement - Residual resistance ratio of Nb-Ti and Nb3Sn composite superconductors (IEC 61788-4:2016) Supraconductivit - Partie 4: Mesurage du rapport de rsistance rsiduelle - Rapport de rsistance rsidue
6、lle des composites supraconducteurs de Nb-Ti et de Nb3Sn (IEC 61788-4:2016) Supraleitfhigkeit - Teil 4: Messung des Restwiderstandsverhltnisses - Restwiderstandsverhltnis von Nb-Ti und Nb3Sn Verbundsupraleitern (IEC 61788-4:2016) This European Standard was approved by CENELEC on 2016-02-23. CENELEC
7、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 appli
8、cation 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-CEN
9、ELEC Management 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, Ic
10、eland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Euro
11、pisches Komitee fr Elektrotechnische Normung CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2016 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members. Ref. No. EN 61788-4:2016 E BS EN 61788-4:2016EN 61788-4:2016 2 European foreword
12、The text of document 90/359/FDIS, future edition 4 of IEC 61788-4, prepared by IEC/TC 90 “Superconductivity“ was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as EN 61788-4:2016. The following dates are fixed: latest date by which the document has to be implemented at national l
13、evel by publication of an identical national standard or by endorsement (dop) 2016-11-23 latest date by which the national standards conflicting with the document have to be withdrawn (dow) 2019-02-23 This document supersedes EN 61788-4:2011. Attention is drawn to the possibility that some of the el
14、ements of this document may be the subject of patent rights. CENELEC and/or CEN shall not be held responsible for identifying any or all such patent rights. Endorsement notice The text of the International Standard IEC 61788-4:2016 was approved by CENELEC as a European Standard without any modificat
15、ion. BS EN 61788-4:2016EN 61788-4:2016 3 Annex ZA (normative) Normative references to international publications with their corresponding European publications The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dat
16、ed references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. NOTE 1 When an International Publication has been modified by common modifications, indicated by (mod), the relevant EN/HD applies. NOTE 2 Up-to-da
17、te information on the latest versions of the European Standards listed in this annex is available here: www.cenelec.eu. Publication Year Title EN/HD Year IEC 60050-815 - International Electrotechnical Vocabulary (IEV) - Part 815: Superconductivity - - BS EN 61788-4:2016 2 IEC 61788-4:2016 IEC 2016 C
18、ONTENTS FOREWORD . 4 INTRODUCTION . 6 1 Scope 7 2 Normative references 7 3 Terms and definitions 7 4 Principle 8 5 Apparatus 8 5.1 Material of measurement mandrel or of measurement base plate 8 5.2 Diameter of the measurement mandrel and length of the measurement base plate . 8 5.3 Cryostat for the
19、resistance (R2) measurement . 9 6 Specimen preparation 9 7 Data acquisition and analysis 9 7.1 Resistance (R1) at room temperature 9 7.2 Resistance (R2or *2R ) just above the superconducting transition 9 7.2.1 Correction of strain effect 9 7.2.2 Data acquisition of cryogenic resistance 10 7.2.3 Opti
20、onal acquisition methods . 12 7.3 Correction on measured *2R of Nb-Ti composite superconductor for bending strain 12 7.4 Residual resistance ratio (RRR) 12 8 Uncertainty and stability of the test method . 12 8.1 Temperature . 12 8.2 Voltage measurement . 12 8.3 Current . 13 8.4 Dimension . 13 9 Test
21、 report . 13 9.1 RRR value 13 9.2 Specimen 13 9.3 Test conditions . 14 9.3.1 Measurements of R1and R2. 14 9.3.2 Measurement of R114 9.3.3 Measurement of R214 Annex A (informative) Additional information relating to the measurement of RRR . 15 A.1 Recommendation on specimen mounting orientation . 15
22、A.2 Alternative methods for increasing temperature of specimen above superconducting transition temperature 15 A.3 Alternative measurement methods of R2or *2R . 15 A.4 Bending strain dependency of RRR for Nb-Ti composite superconductor 18 A.5 Procedure of correction of bending strain effect 21 Annex
23、 B (informative) Uncertainty considerations 23 B.1 Overview. 23 B.2 Definitions. 23 B.3 Consideration of the uncertainty concept 23 BS EN 61788-4:2016IEC 61788-4:2016 IEC 2016 3 B.4 Uncertainty evaluation example for TC 90 standards . 25 Annex C (informative) Uncertainty evaluation in test method of
24、 RRR for Nb-Ti and Nb3Sn composite superconductors . 27 C.1 Evaluation of uncertainty . 27 C.2 Summary of round robin test of RRR of a Nb-Ti composite superconductor . 30 C.3 Reason for large COV value in the intercomparison test on Nb3Sn composite superconductor . 31 Bibliography 32 Figure 1 Relati
25、onship between temperature and resistance 8 Figure 2 Voltage versus temperature curves and definitions of each voltage 10 Figure A.1 Definition of voltages 17 Figure A.2 Bending strain dependency of RRR value for pure Cu matrix of Nb-Ti composite superconductors (comparison between measured values a
26、nd calculated values) 19 Figure A.3 Bending strain dependency of RRR value for round Cu wires 19 Figure A.4 Bending strain dependency of normalized RRR value for round Cu wires 20 Figure A.5 Bending strain dependency of RRR value for rectangular Cu wires . 20 Figure A.6 Bending strain dependency of
27、normalized RRR value for rectangular Cu wires . 21 Figure C.1 Distribution of observed rRRRof Cu/Nb-Ti composite superconductor . 31 Table A.1 Minimum diameter of the measurement mandrel for round wires 21 Table A.2 Minimum diameter of the measurement mandrel for rectangular wires 21 Table B.1 Outpu
28、t signals from two nominally identical extensometers 24 Table B.2 Mean values of two output signals . 24 Table B.3 Experimental standard deviations of two output signals 24 Table B.4 Standard uncertainties of two output signals 25 Table B.5 COV values of two output signals . 25 Table C.1 Uncertainty
29、 of each measurement 30 Table C.2 Obtained values of R1, R2and rRRRfor three Nb3Sn samples 31 BS EN 61788-4:2016 4 IEC 61788-4:2016 IEC 2016 INTERNATIONAL ELECTROTECHNICAL COMMISSION _ SUPERCONDUCTIVITY Part 4: Residual resistance ratio measurement Residual resistance ratio of Nb-Ti and Nb3Sn compos
30、ite superconductors FOREWORD 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international co-operation on all questions concerning st
31、andardization in the electrical and electronic fields. To this end and in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their prepar
32、ation 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. IEC collaborates closely wi
33、th the International Organization for Standardization (ISO) in accordance with conditions determined by agreement between the two organizations. 2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international consensus of opinion on the relevant sub
34、jects since each technical committee has representation from all interested IEC National Committees. 3) IEC Publications have the form of recommendations for international use and are accepted by IEC National Committees in that sense. While all reasonable efforts are made to ensure that the technica
35、l content of IEC Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any misinterpretation by any end user. 4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications transparently to the maximum extent
36、possible in their national and regional publications. Any divergence between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter. 5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide con
37、formity assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any services carried out by independent certification bodies. 6) All users should ensure that they have the latest edition of this publication. 7) No liability shall attach to IEC or its dir
38、ectors, employees, servants or agents including individual experts and members of its technical committees and IEC National Committees for any personal injury, property damage or other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and expenses arisi
39、ng out of the publication, use of, or reliance upon, this IEC Publication or any other IEC Publications. 8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is indispensable for the correct application of this publication. 9) Attention is d
40、rawn to the possibility that some of the elements of this IEC Publication may be the subject of patent rights. IEC shall not be held responsible for identifying any or all such patent rights. International Standard IEC 61788-4 has been prepared by IEC technical committee 90: Superconductivity. This
41、fourth edition cancels and replaces the third edition published in 2011. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: a) the unification of similar test methods for residual resistance ratio (RR
42、R) of Nb-Ti and Nb3Sn composite superconductors, the latter of which is described in IEC 61788-11. BS EN 61788-4:2016IEC 61788-4:2016 IEC 2016 5 The text of this standard is based on the following documents: FDIS Report on voting 90/359/FDIS 90/360/RVD Full information on the voting for the approval
43、 of this standard can be found in the report on voting indicated in the above table. This publication has been drafted in accordance with the ISO/IEC Directives, Part 2. A list of all parts of the IEC 61788 series, published under the general title Superconductivity, can be found on the IEC website.
44、 The committee has decided that the contents of this publication will remain unchanged until the stability date indicated on the IEC website under “http:/webstore.iec.ch“ in the data related to the specific publication. At this date, the publication will be reconfirmed, withdrawn, replaced by a revi
45、sed edition, or amended. IMPORTANT The colour inside logo on the cover page of this publication indicates that it contains colours which are considered to be useful for the correct understanding of its contents. Users should therefore print this document using a colour printer. BS EN 61788-4:2016 6
46、IEC 61788-4:2016 IEC 2016 INTRODUCTION Copper, Cu/Cu-Ni or aluminium is used as matrix material in Nb-Ti and Nb3Sn composite superconductors and works as an electrical shunt when the superconductivity is interrupted. It also contributes to recovery of the superconductivity by conducting heat generat
47、ed in the superconductor to the surrounding coolant. The cryogenic-temperature resistivity of copper is an important quantity, which influences the stability and AC losses of the superconductor. The residual resistance ratio is defined as a ratio of the resistance of the superconductor at room tempe
48、rature to that just above the superconducting transition. This part of IEC 61788 specifies the test method for residual resistance ratio of Nb-Ti and Nb3Sn composite superconductors. The curve method is employed for the measurement of the resistance just above the superconducting transition. Other m
49、ethods are described in A.3. BS EN 61788-4:2016IEC 61788-4:2016 IEC 2016 7 SUPERCONDUCTIVITY Part 4: Residual resistance ratio measurement Residual resistance ratio of Nb-Ti and Nb3Sn composite superconductors 1 Scope This part of IEC 61788 specifies a test method for the determination of the residual resistance ratio (RRR) of Nb-Ti and Nb3Sn composite superconductors with Cu, Cu-Ni, Cu/Cu-Ni and Al matrix. This method is intended for use with supercond
