1、BSI Standards PublicationSuperconductivityPart 5: Matrix to superconductor volume ratio measurement Copper to superconductor volume ratio of Cu/Nb-Ti composite superconducting wiresBS EN 61788-5:2013National forewordThis British Standard is the UK implementation of EN 61788-5:2013. It is identical t
2、o IEC 61788-5:2013. It supersedes BS EN 61788-5:2001 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee L/-/90, Super Conductivity.A list of organizations represented on this committee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 pu
3、rport to include all the necessary provisions ofa contract. Users are responsible for its correct application. The British Standards Institution 2013.Published by BSI Standards Limited 2013ISBN 978 0 580 75668 9ICS 17.220.20; 29.050Compliance with a British Standard cannot confer immunity fromlegal
4、obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 30 September 2013.Amendments/corrigenda issued since publicationDate Text affectedBRITISH STANDARDBS EN 61788-5:2013EUROPEAN STANDARD EN 61788-5 NORME EUROPENNE EUROPISCHE NORM Septem
5、ber 2013 CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung CEN-CENELEC Management Centre: Avenue Marnix 17, B - 1000 Brussels 2013 CENELEC - All rights of exploitation in any form and by an
6、y means reserved worldwide for CENELEC members. Ref. No. EN 61788-5:2013 E ICS 17.220.20; 29.050 Supersedes EN 61788-5:2001 English version Superconductivity - Part 5: Matrix to superconductor volume ratio measurement - Copper to superconductor volume ratio of Cu/Nb-Ti composite superconducting wire
7、s (IEC 61788-5:2013) Supraconductivit - Partie 5 : Mesure du rapport volumique matrice/supraconducteur - Rapport volumique cuivre/supraconducteur des fils en composite supraconducteur Cu/Nb-Ti (CEI 61788-5:2013) Supraleitfhigkeit - Teil 5: Messung des Verhltnisses von Matrixvolumen zu Supraleitervol
8、umen - Verhltnis von Kupfervolumen zu Supraleitervolumen von Cu/Nb-Ti Verbundsupraleiterdrhten (IEC 61788-5:2013) This European Standard was approved by CENELEC on 2013-07-02. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
9、 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 CEN-CENELEC Management Centre or to any CENELEC member. This European Standard exists in three officia
10、l 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 Management Centre has the same status as the official versions. CENELEC members are the national electrotechnic
11、al committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slo
12、vakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. BS EN 61788-5:2013EN 61788-5:2013 - 2 - Foreword The text of document 90/321/FDIS, future edition 2 of IEC 61788-5, prepared by IEC/TC 90 “Superconductivity“ was submitted to the IEC-CENELEC parallel vote and approved by CEN
13、ELEC as EN 61788-5:2013. The following dates are fixed: latest date by which the document has to be implemented at national level by publication of an identical national standard or by endorsement (dop) 2014-04-02 latest date by which the national standards conflicting with the document have to be w
14、ithdrawn (dow) 2016-07-02 This document supersedes EN 61788-5:2001. EN 61788-5:2013 includes the following significant technical changes with respect to EN 61788-5:2001: The main revisions are the addition of two new annexes, “Uncertainty considerations“ (Annex E) and “Uncertainty evaluation in test
15、 method of copper to superconductor volume ratio of Cu/Nb-Ti composite superconductors“ (Annex F). Attention is drawn to the possibility that some of the elements 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 pa
16、tent rights. Endorsement notice The text of the International Standard IEC 61788-5:2013 was approved by CENELEC as a European Standard without any modification. BS EN 61788-5:2013- 3 - EN 61788-5:2013 Annex ZA (normative) Normative references to international publications with their corresponding Eu
17、ropean publications The following documents, in whole or in part, are normatively 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 amendmen
18、ts) applies. NOTE When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD applies. Publication Year Title EN/HD Year IEC 60050-815 Series International Electrotechnical Vocabulary (IEV) - - BS EN 61788-5:2013 2 61788-5 IEC:2013 CONTENTS INT
19、RODUCTION . 5 1 Scope . 6 2 Normative references . 6 3 Terms and definitions . 6 4 Principle . 7 5 Chemicals 7 6 Apparatus . 7 7 Measurement procedure . 8 Quantity of specimen . 8 7.1Removal of insulating cover material . 8 7.2Cleaning 8 7.3Drying . 8 7.4Measurement of specimen mass and its repetiti
20、on . 8 7.5Dissolving copper 8 7.6Cleaning and drying the Nb-Ti filaments 9 7.7Measurement of dissolved specimen mass and its repetition . 9 7.8Procedural repetition for second specimen 10 7.98 Calculation of results 10 9 Uncertainty of the test method 10 10 Test report 11 Identification of test spec
21、imen . 11 10.1Report of copper to superconductor volume ratio . 11 10.2Report of test conditions 11 10.3Annex A (normative) Copper to superconductor volume ratio copper mass method 12 Annex B (informative) Specific mass depending on Nb-Ti fraction . 14 Annex C (information) Mechanical removal of ins
22、ulating cover materials 15 Annex D (informative) Second etch of specimen . 16 Annex E (informative) Uncertainty considerations . 17 Annex F (informative) Uncertainty evaluation in the test method of copper to superconductor volume ratio of Cu/Nb-Ti composite superconductors . 22 Table B.1 Specific m
23、ass of Nb-Ti . 14 Table E.1 Output signals from two nominally identical extensometers 18 Table E.2 Mean values of two output signals . 18 Table E.3 Experimental standard deviations of two output signals 18 Table E.4 Standard uncertainties of two output signals 19 Table E.5 Coefficient of variations
24、of two output signals . 19 BS EN 61788-5:201361788-5 IEC:2013 5 INTRODUCTION The copper to superconductor volume ratio of composite superconductors is used mainly to calculate the critical current density of superconducting wires. The test with the method given in this International Standard may be
25、used to provide part of the information needed to determine the suitability of a specific superconductor. Moreover, this method is useful for quality control, acceptance or research testing if the precautions given in this standard are observed. The test method given in this International Standard i
26、s based on the condition that the specific mass of Nb-Ti is known or the Nb-Ti alloy fraction is known and Annex B can be used to estimate the specific mass. If the specific mass of Nb-Ti is unknown and the Nb-Ti alloy fraction is unknown and/or the fraction of Nb barrier is unknown, another method
27、to determine the copper to superconductor volume ratio of composite superconductors is described in Annex A. BS EN 61788-5:2013 6 61788-5 IEC:2013 SUPERCONDUCTIVITY Part 5: Matrix to superconductor volume ratio measurement Copper to superconductor volume ratio of Cu/Nb-Ti composite superconducting w
28、ires 1 Scope This part of IEC 61788 covers a test method for the determination of copper to superconductor volume ratio of Cu/Nb-Ti composite superconducting wires. This test method and the alternate method in Annex A are intended for use with Cu/Nb-Ti composite superconducting wires with a cross-se
29、ctional area of 0,1 mm2to 3 mm2, a diameter of the Nb-Ti filament(s) of 2 m to 200 m, and a copper to superconductor volume ratio of 0,5 or more. The Cu/Nb-Ti composite test conductor discussed in this method has a monolithic structure with a round or rectangular cross-section. This test method is c
30、arried out by dissolving the copper with nitric acid. Deviations from this test method that are allowed for routine tests and other specific restrictions are given in this standard. Cu/Nb-Ti composite superconducting wires beyond the limits in the cross-sectional area, the filament diameter and the
31、copper to superconductor volume ratio could be measured with this present method with an anticipated reduction of uncertainty. Other, more specialized, specimen test geometries may be more appropriate for conductors beyond the limits and have been omitted from this present standard for simplicity an
32、d to retain low uncertainty. The test method given in this standard is expected to apply to other superconducting composite wires after some appropriate modifications. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensab
33、le 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 60050-815 (all parts), International Electrotechnical Vocabulary (available at ) 3 Terms and definitions For the
34、 purposes of this document, the definitions given in IEC 60050-815 as well as the following definition apply. 3.1copper to superconductor volume ratio ratio of the volume of the copper stabilizing material to the volume without copper consisting of Nb-Ti filaments and their Nb barriers BS EN 61788-5
35、:201361788-5 IEC:2013 7 4 Principle The test method utilizes the nature of the Cu/Nb-Ti composite superconducting wire whereby the copper dissolves in nitric acid solution but the Nb-Ti filaments and Nb barriers do not. After measuring its mass, dip the specimen into the nitric acid solution to diss
36、olve only the copper. Then measure the mass of the remaining Nb-Ti filaments and their Nb barriers. The volume and mass of the starting wire and the mass of the filaments are used to determine the copper to superconductor volume ratio. 5 Chemicals The following chemicals shall be prepared for sample
37、 preparation: a) nitric acid solution consisting of nitric acid (a volume fraction of 50 % to 65 % recommended) and distilled water; b) organic solvent; c) degreasing solvent; d) ethyl alcohol; e) distilled (pure) water. NOTE When nitric acid of more than a mass fraction of 65 % is used, the acid is
38、 diluted with distilled water within the range of the above content. 6 Apparatus The following apparatus shall be prepared. Draft chamber Balance A balance shall have a manufacturers specified uncertainty of 0,1 mg or better. Dryer or drying oven A dryer or a drying oven shall be used for evaporatin
39、g moisture after washing the specimen. Beaker Watch-glass Plastic tweezers Filter papers Thermometer Rubber gloves and protection spectacles Rubber gloves and protection spectacles shall be used for protecting the human body from the harmful acid liquid or fumes. The dissolution of the specimen shal
40、l be performed in a draft chamber in order to protect the human body. BS EN 61788-5:2013 8 61788-5 IEC:2013 7 Measurement procedure Quantity of specimen 7.1Take a specimen of around 1 g to 10 g in mass from the base test material. Removal of insulating cover material 7.2An appropriate organic solven
41、t, which does not erode the copper, shall be used to remove any insulating cover material of the specimen. Finally, it shall be visually checked that the insulating cover material no longer remains. If no organic solvents can remove the insulating cover material, the mechanical removal in Annex C is
42、 an alternative. Cleaning 7.3A degreaser shall be used to remove oil and/or grease traces from the specimen, whose cover material has been removed. It shall then be cleaned with pure water. Finally, the degreased specimen shall be dipped into ethyl alcohol to replace the water. Cleaning without usin
43、g ethyl alcohol is an alternative, by using the drying process described in 7.4. Drying 7.4The clean specimen shall be placed on a watch-glass and dried fully in a dryer or a drying oven at a temperature of 60 C or lower with the holding time more than 0,5 hours. When cleaning the specimen is carrie
44、d out without ethyl alcohol, the specimen shall be dried fully in a dryer or a drying oven at a temperature of 100 C with the holding time more than 0,5 hours. Measurement of specimen mass and its repetition 7.5When the specimen is cooled down to 35 C or lower, its mass shall be measured on a sheet
45、of weighing paper, using a balance with a manufacturers specified uncertainty of 0,1 mg or better. After completion of this mass measurement (the first measurement), remove the specimen from the balance. To assure that the specimen has been fully dried, the mass of the specimen shall be measured aga
46、in about 10 min after the first measurement (the second measurement). The difference in mass between the first and second measurements shall be within 0,5 %. If this difference is within 0,5 %, the average of the two measurements shall be regarded as the mass of the specimen. If the difference in ma
47、ss is more than 0,5 %, cleaning of the specimen with ethyl alcohol and drying of the specimen shall be repeated as described in 7.3, 7.4 and 7.5 until the difference in mass of the two measurements is within 0,5 %. As soon as this part of the method is qualified by a successful repetition, the secon
48、d mass measurement can be omitted in subsequent measurements. However, periodic re-qualification shall be performed every six months or after changes of equipment or personnel. Dissolving copper 7.6The copper shall be dissolved from the specimen in the following manner. BS EN 61788-5:201361788-5 IEC
49、:2013 9 Put approximately 150 ml of the nitric acid solution in a 300 ml beaker. Tie a knot in the specimen to help retain all of the filaments upon completion of the etch. In the draft chamber, while maintaining the temperature of the nitric acid solution between 20 C and 50 C, the whole specimen shall be dipped into the nitric acid solution for 30 min to 1 h to completely dissolve the copper of the specimen. It shall be checked visually that the copper has been completely diss
