EN 61788-4:2007

SLOVENSKI STANDARD
01-januar-2008
1DGRPHãþD
SIST EN 61788-4:2002
Superprevodnost - 4. del: Meritve razmerja preostale upornosti - Preostala
upornost za superprevodnike iz kompozita Nb-Ti (IEC 61788-4:2007)
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 61788-4:2007
ICS:
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.

EUROPEAN STANDARD
EN 61788-4
NORME EUROPÉENNE
July 2007
EUROPÄISCHE NORM
ICS 17.220.20; 29.050 Supersedes EN 61788-4:2001

English version
Superconductivity -
Part 4: Residual resistance ratio measurement -
Residual resistance ratio of Nb-Ti composite superconductors
(IEC 61788-4:2007)
Supraconductivité -  Supraleitfähigkeit -
Partie 4: Mesure Teil 4: Messungen
de la résistivité résiduelle - des Restwiderstandsverhältnisses –
Taux de résistivité résiduelle Restwiderstandsverhältnis
des supraconducteurs composites von Nb-Ti-Verbundsupraleitern
au Nb-Ti (IEC 61788-4:2007)
(CEI 61788-4:2007)
This European Standard was approved by CENELEC on 2007-07-01. 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, 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.

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

Central Secretariat: rue de Stassart 35, B - 1050 Brussels

© 2007 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 61788-4:2007 E
Foreword
The text of document 90/203/FDIS, future edition 2 of IEC 61788-4, prepared by IEC TC 90,
Superconductivity, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as
EN 61788-4 on 2007-07-01.
This European Standard supersedes EN 61788-4:2001.
The main revisions are the replacement of "accuracy" by "uncertainty" and a change in Figure 1, where
the relationship between temperature and voltage is changed to the relationship between temperature
and resistance.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement (dop) 2008-04-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2010-07-01
Annex ZA has been added by CENELEC.
__________
Endorsement notice
The text of the International Standard IEC 61788-4:2007 was approved by CENELEC as a European
Standard without any modification.
__________
- 3 - EN 61788-4:2007
Annex ZA
(normative)
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
applies.
Publication Year Title EN/HD Year
1)
IEC 60050-815 - International Electrotechnical Vocabulary - -
(IEV) -
Part 815: Superconductivity
1)
Undated reference.
INTERNATIONAL IEC
STANDARD 61788-4
Second edition
2007-04
Superconductivity –
Part 4:
Residual resistance ratio measurement –
Residual resistance ratio of Nb-Ti
composite superconductors
PRICE CODE
Commission Electrotechnique Internationale T
International Electrotechnical Commission
МеждународнаяЭлектротехническаяКомиссия
For price, see current catalogue

– 2 – 61788-4 © IEC:2007(E)
CONTENTS
FOREWORD.3
INTRODUCTION.5

1 Scope.6
2 Normative references .6
3 Terms and definition.6
4 Requirements .7
5 Apparatus.7
5.1 Material of measuring mandrel or of measuring base plate .7
5.2 Diameter of the measuring mandrel and length of the measuring base plate.7
5.3 Cryostat for the resistance, R , measurement .8
6 Specimen preparation.8
7 Data acquisition and analysis .8
7.1 Resistance (R ) at room temperature .8
7.2 Resistance (R *) just above the superconducting transition.8
7.3 Correction on measured R * for bending strain.11
7.4 Residual resistance ratio (RRR) .11
8 Uncertainty and stability of the test method .11
8.1 Temperature.11
8.2 Voltage measurement.11
8.3 Current.11
8.4 Dimension .12
9 Test report.12
9.1 RRR value.12
9.2 Specimen .12
9.3 Test conditions.12
9.3.1 Report of test conditions.12
9.3.2 Report of R .13
9.3.3 Report of R .13
Annex A (informative) Additional information relating to the measurement of RRR .
Annex B (informative) Statistical definitions .22

Figure 1 – Relationship between temperature and resistance .7
Figure 2 – Voltage versus temperature curves and definitions of each voltage.9
Figure A.1 – Bending strain dependency of RRR for pure Cu matrix of Nb-Ti composite
superconductors (comparison between measured values and calculated values) .15
Figure A.2 – Bending strain dependency of RRR for round Cu wires .15
Figure A.3 – Bending strain dependency of normalized RRR for round Cu wires .16
Figure A.4 – Bending strain dependency of RRR for rectangular Cu wires .16
Figure A.5 – Bending strain dependency of normalized RRR for rectangular Cu wires .17
Figure A.6 – Distribution of observed RRR of Cu/Nb-Ti composite superconductor .19
Figure A.7 – Definition of voltages .20

61788-4 © IEC:2007(E) – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
___________
SUPERCONDUCTIVITY –
Part 4: Residual resistance ratio measurement –
Residual resistance ratio of Nb-Ti composite 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 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 provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
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
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 drawn 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 second edition cancels and replaces the first edition published in 2001. It constitutes a
technical revision. The main revisions are the replacement of “accuracy” by “uncertainty” and
a change in Figure 1, where the relationship between temperature and voltage is changed to
the relationship between temperature and resistance.
The text of this standard is based on the following documents:
FDIS Report on voting
90/203/FDIS 90/205/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.

– 4 – 61788-4 © IEC:2007(E)
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.
The committee has decided that the contents of this publication will remain unchanged until
the maintenance result date indicated on the IEC web site under "http://webstore.iec.ch" in
the data related to the specific publication. At this date, the publication
...