kSIST FprEN IEC 61788-27:2024

SLOVENSKI STANDARD
oSIST prEN IEC 61788-27:2024
01-februar-2024
Merjenje naklona praktičnih superprevodnih žic - Metoda merjenja naklona
kompozitnih superprevodnikov NbTi in Nb3Sn
Twist pitch measurement of practical superconducting wires - Twist pitch measurement
method of NbTi and Nb3Sn composite superconductors
Ta slovenski standard je istoveten z: prEN IEC 61788-27:2023
ICS:
17.220.20 Merjenje električnih in Measurement of electrical
magnetnih veličin and magnetic quantities
29.050 Superprevodnost in prevodni Superconductivity and
materiali conducting materials
oSIST prEN IEC 61788-27:2024 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

oSIST prEN IEC 61788-27:2024
oSIST prEN IEC 61788-27:2024
90/507/CDV
COMMITTEE DRAFT FOR VOTE (CDV)

PROJECT NUMBER:
IEC 61788-27 ED1
DATE OF CIRCULATION: CLOSING DATE FOR VOTING:
2023-10-20 2024-01-12
SUPERSEDES DOCUMENTS:
90/498/CD, 90/502/CC
IEC TC 90 : SUPERCONDUCTIVITY
SECRETARIAT: SECRETARY:
Japan Mr Jun Fujikami
OF INTEREST TO THE FOLLOWING COMMITTEES: PROPOSED HORIZONTAL STANDARD:

Other TC/SCs are requested to indicate their interest, if any, in
this CDV to the secretary.
FUNCTIONS CONCERNED:
EMC ENVIRONMENT QUALITY ASSURANCE SAFETY
SUBMITTED FOR CENELEC PARALLEL VOTING NOT SUBMITTED FOR CENELEC PARALLEL VOTING
Attention IEC-CENELEC parallel voting
The attention of IEC National Committees, members of
CENELEC, is drawn to the fact that this Committee Draft for
Vote (CDV) is submitted for parallel voting.
The CENELEC members are invited to vote through the
CENELEC online voting system.
This document is still under study and subject to change. It should not be used for reference purposes.
Recipients of this document are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.
Recipients of this document are invited to submit, with their comments, notification of any relevant “In Some Countries” clau ses
to be included should this proposal proceed. Recipients are reminded that the CDV stage is the final stage for submitting ISC
clauses. (SEE AC/22/2007 OR NEW GUIDANCE DOC).

TITLE:
Twist pitch measurement of practical superconducting wires - Twist pitch measurement method of NbTi
and Nb3Sn composite superconductors

PROPOSED STABILITY DATE: 2031
NOTE FROM TC/SC OFFICERS:
electronic file, to make a copy and to print out the content for the sole purpose of preparing National Committee positions.
You may not copy or "mirror" the file or printed version of the document, or any part of it, for any other purpose without

permission in writing from IEC.

oSIST prEN IEC 61788-27:2024
IEC CDV 61788-27 © IEC:2023 – 2 – 90/507/CDV

1 CONTENTS
2 FOREWORD . 4
3 INTRODUCTION . 6
4 1 Scope . 7
5 2 Normative references . 7
6 3 Terms and definitions . 7
7 4 Principle . 8
8 5 Reagents and auxiliary materials . 8
9 6 Apparatus and tools . 9
10 7 Specimen preparation . 9
11 7.1 Requirements . 9
12 7.2 Cleaning . 9
13 7.3 Drying . 9
14 7.4 Removing matrix copper and sanding barrier (apply to Nb-Sn/Cu specimen
15 of external stabilizer type only) . 9
16 8 Measurement procedure . 10
17 8.1 Specimen fixation . 10
18 8.2 Specimen dissolution . 10
19 8.3 Cleaning and drying . 10
20 8.4 Measurement . 10
21 9 Calculation of results . 10
22 10 Uncertainty of measurement . 11
23 11 Test report . 11
24 11.1 Specimen . 11
25 11.2 Results . 11
26 Annex A (normative)  Measurement – Direct measurement method . 12
27 A.1 Method . 12
28 A.2 Measurement procedure . 12
29 A.3 Uncertainty of measurement . 13
30 A.4 Test report . 13
31 Annex B (normative)  Measurement – Image processing method . 14
32 B.1 Method . 14
33 B.2 Measurement procedure . 15
34 B.3 Uncertainty of measurement . 16
35 B.4 Test report . 16
36 Annex C (informative)  A typical design of the auxiliary tool for twist pitch
37 measurement by the untwisting method . 17
38 C.1 Apparatus of twist angle measurement . 17
39 C.2 Measurement procedure . 18
40 Annex D (informative)  Uncertainty evaluation . 20
41 D.1 Untwisting method . 20
42 D.2 Direct measurement method . 24

oSIST prEN IEC 61788-27:2024
IEC CDV 61788-27 © IEC:2023 – 3 – 90/507/CDV
43 D.3 Image processing method . 28
46 Figure 1–Principle demonstration . 9
47 Figure B.1–Principle demonstration for image processing method . 15
48 Figure B.2–Measurement of twist angle . 17
49 Figure C.1–A typical design of the auxiliary tool for twist pitch measurement. (a)
50 schematic of the tool, (b) design drawings, and (c) details of part C . 19
51 Figure C.2–Specimen fixation . 19
52 Figure C.3–Specimen bending and dissolution . 19
53 Figure C.4–Back to the initial state . 19
54 Figure C.5–Rotate rotating knob to untwist filaments . 19
55 Figure C.6–Judge the parallelism of filaments . 19
56 Figure C.7–Measure the distance . 20
57 Table D.1–Measurement results of dissolved length (Nb-Ti/Cu) . 21
58 Table D.2–Measurement results of untwisted angle  (Nb-Ti/Cu) . 22
59 Table D.3–Measurement results of dissolved length (Nb-Sn/Cu) . 23
60 Table D.4–Measurement results of untwisted angle  (Nb-Sn/Cu) . 24
61 Table D.5–RRT results of Nb-Ti/Cu specimens . 24
62 Table D.6–RRT results of Nb-Sn/Cu specimens . 25
63 Table D.7–Measurement results and uncertainties of each institution for Nb-Ti/Cu
64 specimen . 25
65 Table D.8–Measurement results and uncertainties of each institution for Nb-Sn/Cu
66 specimen . 25
67 Table D.9–Measured twist pitches for Nb-Ti/Cu specimen . 26
68 Table D.10–RRT results of Nb-Ti/Cu specimen ……………………………………………………28
69 Table D.11–RRT results of Nb-Sn/Cu specimen ………………………………………………….28
70 Table D.12–Measurement results and uncertainties of each institution for Nb-Ti/Cu
71 specimen……………………………………………………………………………………………………28
72 Table D.13–Measurement results and uncertainties of each institution for Nb-Sn/Cu
73 specimen. ………………………………………………………………………………………………….29
74 Table D.14–Measured diameter (D ), helix angle (𝜑 ) and obtained L for Nb-Ti/Cu
i i pi
75 specimen……………………………………………………………………………………………………30
76 Table D.15–RRT results of Nb-Ti/Cu specimen. . 31
77 Table D.16–RRT results of Nb-Sn/Cu specimen ………………………………………………….31
78 Table D.17–Measurement results and uncertainties of each institution for Nb-Ti/Cu
79 specimen. ………………………………………………………………………………………………….32
80 Table D.18–Measurements results and uncertainties of each institution for Nb-Sn/Cu
81 specimen. ………………………………………………………………………………………………….32
oSIST prEN IEC 61788-27:2024
IEC CDV 61788-27 © IEC:2023 – 4 – 90/507/CDV
83 INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
84 SUPERCONDUCTIVITY–
85 Part 27: Twist pitch measurement of practical superconducting wires—
86 Twist pitch measurement of Nb-Ti/Cu and Nb-Sn/Cu composite
87 superconductors
88 FOREWORD
89 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
90 all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
91 co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
92 in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,
93 Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their
94 preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
95 may participate in this preparatory work. International, governmental and non-governmental organizations liaising
96 with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for
97 Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
98 2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
99 consensus of opinion on the relevant subjects since each technical committee has representation from all
100 interested IEC National Committees.
101 3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
102 Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
103 Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
104 misinterpretation by any end user.
105 4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
106 transparently to the maximum extent possible in their national and regional publications. Any divergence between
107 any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
108 5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
109 assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsib
...