Superconductivity - Part 4: Residual resistance ratio measurement - Residual resistance ratio of Nb-Ti composite superconductors

IEC 61788-4:2011 covers a test method for the determination of the residual resistance ratio (RRR) of composite superconductors comprised of Nb-Ti filaments and Cu, Cu-Ni or Cu/Cu-Ni matrix. This method is intended for use with superconductors that have a monolithic structure with rectangular or round cross-section, RRR less than 350, and cross-sectional area less than 3 mm2. All measurements are done without an applied magnetic field. The method described in the body of this standard is the 'reference' method and optional acquisition methods are outlined in Clause A.3. This third edition constitutes a technical revision which adds two new annexes: 'Uncertainty considerations' (Annex B) and 'Uncertainty evaluation in test method of RRR for NbTi' (Annex C). Copper is used as a matrix material in multifilamentary superconductors and works as an electrical shunt when the superconductivity is interrupted. It also contributes to recovery of the superconductivity by conducting heat generated in the superconductor to the surrounding coolant. The cryogenic-temperature resistivity of copper is an important quantity, which influences the stability of the superconductor. The residual resistance ratio is defined as a ratio of the resistance of the superconductor at room temperature to that just above the superconducting transition.

Supraleitfähigkeit - Teil 4: Messung des Restwiderstandsverhältnisses - Restwiderstandsverhältnis von Nb-Ti Verbundsupraleitern

Supraconductivité - Partie 4: Mesure du rapport de résistance résiduelle - Rapport de résistance résiduelle des supraconducteurs composites de Nb-Ti

La CEI 61788-4:2011 spécifie une méthode d'essai pour la détermination du rapport de résistance résiduelle (RRR) de supraconducteurs composites constitués de filaments de Nb-Ti et d'une matrice de Cu, Cu-Ni ou Cu/Cu-Ni. Cette méthode est destinée à être utilisée avec des supraconducteurs présentant une structure monolithique avec une section rectangulaire ou circulaire, un rapport RRR inférieur à 350 et une surface de section inférieure à 3 mm2. Toutes les mesures sont effectuées sans appliquer de champ magnétique. La méthode décrite dans le corps de texte de la présente norme est la méthode de 'référence' et des méthodes d'acquisition facultatives sont présentées à l'Article A.3. Cette troisième édition constitue une révision technique qui ajoute deux nouvelles annexes: 'Considérations relatives à l'incertitude' (Annexe B) et 'Evaluation de l'incertitude de la méthode d'essai de RRR (rapport de résistance résiduelle) de NbTi' (Annexe C). Le cuivre est utilisé comme matériau de matrice dans les supraconducteurs multifilamentaires et fonctionne comme une dérivation électrique lorsque la supraconductivité est interrompue. Il contribue également à la reprise de la supraconductivité en dirigeant la chaleur générée dans le supraconducteur vers le fluide de refroidissement environnant. La résistivité à la température cryogénique du cuivre est une grandeur importante qui influe sur la stabilité du supraconducteur. Le rapport de résistance résiduelle est défini comme le rapport entre la résistance du supraconducteur à température ambiante et celle immédiatement supérieure à la transition supraconductrice.

Superprevodnost - 4. del: Meritve razmerja preostale upornosti - Preostala upornost za superprevodnike iz kompozita Nb-Ti

Ta del IEC 61788 zajema preskusno metodo za določevanje razmerja preostale upornosti (RRR) za kompozitne superprevodnike iz vlaken Nb-Ti in Cu, Cu-Ni ali matrice Cu/Cu-Ni. Ta metoda je namenjena uporabi z vzorci superprevodnikov, ki imajo monolitno strukturo s pravokotnim ali okroglim prečnim prerezom, RRR manj kot 350 in prerezom manj kot 3 mm2. Vse meritve se izvajajo brez vnesenega magnetnega polja. Metoda, opisana v glavnem delu tega standarda, je »referenčna«, izbirne metode so navedene v točki A.3.

General Information

Publication Date
Withdrawal Date
Technical Committee
Drafting Committee
Parallel Committee
Current Stage
9960 - Withdrawal effective - Withdrawal
Start Date
Completion Date


Buy Standard

EN 61788-4:2011
English language
31 pages
sale 10% off
sale 10% off
e-Library read for
1 day

Standards Content (Sample)

Superprevodnost - 4. del: Meritve razmerja preostale upornosti - Preostala
upornost za superprevodnike iz kompozita Nb-Ti
Superconductivity - Part 4: Residual resistance ratio measurement - Residual resistance
ratio of Nb-Ti composite superconductors
Supraleitfähigkeit - Teil 4: Messungen des Restwiderstandsverhältnisses -
Restwiderstandsverhältnis von Nb-Ti-Verbundsupraleitern
Supraconductivité - Partie 4: Mesure de la résistivité résiduelle - Taux de résistivité
résiduelle des supraconducteurs composites au Nb-Ti
Ta slovenski standard je istoveten z: EN 61788-4:2011
17.220.20 0HUMHQMHHOHNWULþQLKLQ Measurement of electrical
PDJQHWQLKYHOLþLQ 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.

EN 61788-4
August 2011
ICS 17.220.20; 29.050 Supersedes EN 61788-4:2007

English version
Superconductivity -
Part 4: Residual resistance ratio measurement -
Residual resistance ratio of Nb-Ti composite superconductors
(IEC 61788-4:2011)
Supraconductivité -  Supraleitfähigkeit -
Partie 4: Mesure du rapport de résistance Teil 4: Messung des
résiduelle - Restwiderstandsverhältnisses -
Rapport de résistance résiduelle des Restwiderstandsverhältnis von Nb-Ti
supraconducteurs composites de Nb-Ti Verbundsupraleitern
(CEI 61788-4:2011) (IEC 61788-4:2011)

This European Standard was approved by CENELEC on 2011-08-15. CENELEC 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
application to the Central Secretariat 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 Central Secretariat 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, France, Germany, Greece, Hungary, Iceland, Ireland, Italy,
Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia,
Spain, Sweden, Switzerland and the United Kingdom.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Management Centre: Avenue Marnix 17, B - 1000 Brussels

© 2011 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 61788-4:2011 E
The text of document 90/263/FDIS, future edition 3 of IEC 61788-4, prepared by IEC TC 90,
Superconductivity was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as
The following dates are fixed:
(dop) 2012-05-15
• latest date by which the document has
to be implemented at national level by
publication of an identical national
standard or by endorsement
• latest date by which the national (dow) 2014-08-15
standards conflicting with the
document have to be withdrawn
This document supersedes EN 61788-4:2007.
The main revisions are the addition of two new annexes, "Uncertainty considerations" (Annex B) and
"Uncertainty evaluation in test method of RRR for NbTi" (Annex C).

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 patent
Endorsement notice
The text of the International Standard IEC 61788-4:2011 was approved by CENELEC as a European
Standard without any modification.

- 3 - EN 61788-4:2011
Annex ZA
Normative references to international publications
with their corresponding European publications

The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.

NOTE  When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD
Publication Year Title EN/HD Year

IEC 60050-815 - International Electrotechnical Vocabulary - - -
Part 815: Superconductivity
IEC 61788-4 ®
Edition 3.0 2011-07
Superconductivity –
Part 4: Residual resistance ratio measurement – Residual resistance ratio of
Nb-Ti composite superconductors

Supraconductivité –
Partie 4: Mesure du rapport de résistance résiduelle – Rapport de résistance
résiduelle des supraconducteurs composites de Nb-Ti

ICS 17.220.20; 29.050 ISBN 978-2-88912-554-8

– 2 – 61788-4  IEC:2011
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 7
4 Requirements . 8
5 Apparatus . 8
5.1 Material of measuring mandrel or of measuring base plate . 8
5.2 Diameter of the measuring mandrel and length of the measuring base plate . 8
5.3 Cryostat for the resistance, R , measurement . 9
6 Specimen preparation. 9
7 Data acquisition and analysis . 9
7.1 Resistance (R ) at room temperature . 9
7.2 Resistance (R *) just above the superconducting transition . 9
7.3 Correction on measured R * for bending strain . 11
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 . 12
8.4 Dimension . 12
9 Test report. 13
9.1 RRR value . 13
9.2 Specimen . 13
9.3 Test conditions . 13
Annex A (informative) Additional information relating to the measurement of RRR . 15
Annex B (informative) Uncertainty considerations . 21
Annex C (informative) Uncertainty evaluation in test method of RRR for Nb-Ti . 25

Figure 1 – Relationship between temperature and resistance. emperature T * is that at
the intersection point . 8
Figure 2 – Voltage (U) versus temperature (T) curves and definitions of each voltage . 10
Figure A.1 – Definition of voltages . 16
Figure A.2 – Bending strain dependency of RRR for pure Cu matrix of Nb-Ti composite
superconductors (comparison between measured values and calculated values) . 18
Figure A.3 – Bending strain dependency of RRR for round Cu wires . 18
Figure A.4 – Bending strain dependency of normalized RRR for round Cu wires . 19
Figure A.5 – Bending strain dependency of RRR for rectangular Cu wires . 19
Figure A.6 – Bending strain dependency of normalized RRR for rectangular Cu wires . 20
Figure C.1 – Distribution of observed RRR of Cu/Nb-Ti composite superconductor . 28

Table B.1 – Output signals from two nominally identical extensometers . 22
Table B.2 – Mean values of two output signals . 22

61788-4  IEC:2011 – 3 –
Table B.3 – Experimental standard deviations of two output signals. 22
Table B.4 – Standard uncertainties of two output signals . 22
Table B.5 – Coefficient of variations of two output signals. 23
Table C.1 – Uncertainty of each measurement . 27

– 4 – 61788-4  IEC:2011
Part 4: Residual resistance ratio measurement –
Residual resistance ratio of Nb-Ti composite superconductors

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 standardization 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 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. IEC 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 IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects 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 technical 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 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 conformity
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 directors, 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 arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
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 drawn to the possibility that some of the elements of this IEC Publication ma

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.