prEN IEC 61788-27:2023

Superconductivity - Part 27: Twist pitch measurement of practical superconducting wires - Twist pitch measurement of nb‑ti/cu and nb‑sn/cu composite superconductors

Bestimmung der Schlaglänge von supraleitenden Drähten – Messverfahren zur Bestimmung der Schlaglänge von verdrillten NbTi und NbSn Verbundsupraleitern

Mesurage du pas de torsade de fils supraconducteurs pratiques - Méthode de mesurage du pas de torsade des composites supraconducteurs nbti et nb3sn

Merjenje naklona praktičnih superprevodnih žic - Metoda merjenja naklona kompozitnih superprevodnikov NbTi in Nb3Sn

General Information

• Status: Not Published
• Publication Date: 11-May-2025
• ICS: 29.050 - Superconductivity and conducting materials
• Technical Committee: CLC/SR 90 - Superconductivity
• Drafting Committee: IEC/TC 90 - IEC_TC_90
• Current Stage: 4060 - Enquiry results established and sent to TC, SR, BTTF - Enquiry
• Start Date: 12-Jan-2024
• Completion Date: 12-Jan-2024
• Ref Project: oSIST prEN IEC 61788-27:2024 - Twist pitch measurement of practical superconducting wires - Twist pitch measurement method of NbTi and Nb3Sn composite superconductors

Standards Content (Sample)

SLOVENSKI STANDARD
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
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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:
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SUBMITTED FOR CENELEC PARALLEL VOTING NOT SUBMITTED FOR CENELEC PARALLEL VOTING
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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
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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.

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

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
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
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