EN IEC 61788-7:2020

Superconductivity - Part 7: Electronic characteristic measurements - Surface resistance of high-temperature superconductors at microwave frequencies

IEC 61788-7:2020 is available as IEC 61788-7:2020 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.IEC 61788-7:2020 describes measurement of the surface resistance (Rs) of superconductors at microwave frequencies by the standard two-resonator method. The object of measurement is the temperature dependence of Rs at the resonant frequency. The applicable measurement range of Rs for this method is as follows: - Frequency: 8 GHz < f < 30 GHz - Measurement resolution: 0,01 m Ω at 10 GHz The Rs data at the measured frequency, and that scaled to 10 GHz, assuming the f 2 rule for comparison, is reported. This third edition cancels and replaces the second edition, published in 2006. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: a) informative Annex B, relative combined standard uncertainty for surface resistance measurement has been added; b) precision and accuracy statements have been converted to uncertainty; c) reproducibility in surface resistant measurement has been added.

Supraleitfähigkeit - Teil 7: Messungen der elektronischen Charakteristik – Oberflächenwiderstand von Hochtemperatur-Supraleitern bei Frequenzen im Mikrowellenbereich

Supraconductivité - Partie 7: Mesurages des caractéristiques électronique - Résistance de surface des supraconducteurs haute température critique aux hyperfréquences

IEC 61788-7:2020 est disponible sous forme de IEC 61788-7:2020 RLV qui contient la Norme internationale et sa version Redline, illustrant les modifications du contenu technique depuis l'édition précédente.IEC 61788-7:2020 décrit le mesurage de la résistance de surface (Rs) des supraconducteurs aux hyperfréquences par la méthode normalisée à deux résonateurs. L'objet du mesurage est la dépendance de la résistance de surface Rs vis-à-vis de la température à la fréquence de résonance. La plage de mesures applicable des résistances de surface Rs pour cette méthode est la suivante: - Fréquence: 8 GHz < f < 30 GHz - Résolution de mesure: 0,01 m Ω à 10 GHz Les données de Rs à la fréquence mesurée, et celles mises à l'échelle à 10 GHz, en prenant pour hypothèse la règle de comparaison f 2, doivent être consignées. Cette troisième édition annule et remplace la deuxième édition parue en 2006. Cette édition constitue une révision technique. Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente: a) l’ajout de l’Annexe B informative, incertitude type composée relative pour le mesurage de la résistance de surface; b) les déclarations de fidélité et d'exactitude ont été converties en incertitude; c) l'ajout de la reproductibilité du mesurage de résistance de surface.

Superprevodnost - 7. del: Meritve elektronskih lastnosti - Površinska upornost visokotemperaturnih superprevodnikov pri mikrovalovnih frekvencah (IEC 61788-7:2020)

General Information

• Status: Published
• Publication Date: 14-May-2020
• ICS: 17.220 - Electricity. Magnetism. Electrical and magnetic measurements
• ICS: 17.220.20 - Measurement of electrical and magnetic quantities
• ICS: 29.050 - Superconductivity and conducting materials
• Technical Committee: CLC/SR 90 - Superconductivity
• Drafting Committee: IEC/TC 90 - IEC_TC_90
• Current Stage: 6060 - Document made available - Publishing
• Start Date: 15-May-2020
• Completion Date: 15-May-2020
• Ref Project: SIST EN IEC 61788-7:2020 - Superconductivity - Part 7: Electronic characteristic measurements - Surface resistance of high-temperature superconductors at microwave frequencies (IEC 61788-7:2020)

Relations

• Replaces: EN 61788-7:2006 - Superconductivity - Part 7: Electronic characteristic measurements - Surface resistance of superconductors at microwave frequencies
• Effective Date: 09-Jan-2018

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN IEC 61788-7:2020
01-julij-2020
Nadomešča:
SIST EN 61788-7:2007
Superprevodnost - 7. del: Meritve elektronskih lastnosti - Površinska upornost
visokotemperaturnih superprevodnikov pri mikrovalovnih frekvencah (IEC 61788-
7:2020)

Superconductivity - Part 7: Electronic characteristic measurements - Surface resistance

of high-temperature superconductors at microwave frequencies (IEC 61788-7:2020)
Supraleitfähigkeit - Teil 7: Charakteristische elektronische Messungen -
Oberflächenwiderstand von Supraleitern bei Frequenzen im Mikrowellenbereich (IEC
61788-7:2020)

Supraconductivité - Partie 7: Mesures des caractéristiques électroniques - Résistance de

surface des supraconducteurs aux hyperfréquences (IEC 61788-7:2020)
Ta slovenski standard je istoveten z: EN IEC 61788-7:2020
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
SIST EN IEC 61788-7:2020 en

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

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SIST EN IEC 61788-7:2020
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SIST EN IEC 61788-7:2020
EUROPEAN STANDARD EN IEC 61788-7
NORME EUROPÉENNE
EUROPÄISCHE NORM
May 2020
ICS 29.050; 17.220.20 Supersedes EN 61788-7:2006 and all of its amendments
and corrigenda (if any)
English Version
Superconductivity - Part 7: Electronic characteristic
measurements - Surface resistance of high-temperature
superconductors at microwave frequencies
(IEC 61788-7:2020)

Supraconductivité - Partie 7: Mesurages des Supraleitfähigkeit - Teil 7: Messungen der elektronischen

caractéristiques électronique - Résistance de surface des Charakteristik - Oberflächenwiderstand von

supraconducteurs haute température critique aux Hochtemperatur-Supraleitern bei Frequenzen im

hyperfréquences Mikrowellenbereich
(IEC 61788-7:2020) (IEC 61788-7:2020)

This European Standard was approved by CENELEC on 2020-04-24. 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 CEN-CENELEC

Management Centre 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 CEN-CENELEC Management Centre 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, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,

Turkey and the United Kingdom.
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels

© 2020 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.

Ref. No. EN IEC 61788-7:2020 E
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SIST EN IEC 61788-7:2020
EN IEC 61788-7:2020 (E)
European foreword

The text of document 90/447/FDIS, future edition 3 of IEC 61788-7, prepared by IEC/TC 90

"Superconductivity" was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as

EN IEC 61788-7:2020.
The following dates are fixed:

• latest date by which the document has to be implemented at national (dop) 2021-01-24

level by publication of an identical national standard or by endorsement

• latest date by which the national standards conflicting with the (dow) 2023-04-24

document have to be withdrawn

This document supersedes EN 61788-7:2006 and all of its amendments and corrigenda (if any).

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.

Endorsement notice

The text of the International Standard IEC 61788-7:2020 was approved by CENELEC as a European

Standard without any modification.
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SIST EN IEC 61788-7:2020
EN IEC 61788-7:2020 (E)
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications

The following documents are referred to in the text in such a way that some or all of their content

constitutes requirements 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 1 Where an International Publication has been modified by common modifications, indicated by (mod), the relevant

EN/HD applies.

NOTE 2 Up-to-date information on the latest versions of the European Standards listed in this annex is available here:

www.cenelec.eu.
Publication Year Title EN/HD Year
IEC 60050-815 - International Electrotechnical Vocabulary - - -
Part 815: Superconductivity
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SIST EN IEC 61788-7:2020
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SIST EN IEC 61788-7:2020
IEC 61788-7
Edition 3.0 2020-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Superconductivity –
Part 7: Electronic characteristic measurements – Surface resistance of
high‑temperature superconductors at microwave frequencies
Supraconductivité –
Partie 7: Mesurages des caractéristiques électronique – Résistance de surface
des supraconducteurs haute température critique aux hyperfréquences
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 17.220.20; 29.050 ISBN 978-2-8322-7917-5

Warning! Make sure that you obtained this publication from an authorized distributor.

Attention! Veuillez vous assurer que vous avez obtenu cette publication via un distributeur agréé.

® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale
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SIST EN IEC 61788-7:2020
– 2 – IEC 61788-7:2020 © IEC 2020
CONTENTS

FOREWORD ........................................................................................................................... 5

INTRODUCTION ..................................................................................................................... 7

1 Scope .............................................................................................................................. 8

2 Normative references ...................................................................................................... 8

3 Terms and definitions ...................................................................................................... 8

4 Requirements .................................................................................................................. 8

5 Apparatus ........................................................................................................................ 9

5.1 Measurement system .............................................................................................. 9

5.2 Measurement apparatus for R .............................................................................. 10

5.3 Dielectric rods ....................................................................................................... 12

6 Measurement procedure ................................................................................................ 12

6.1 Specimen preparation ........................................................................................... 12

6.2 Set-up ................................................................................................................... 13

6.3 Measurement of reference level ............................................................................ 13

6.4 Measurement of the frequency response of resonators ......................................... 14

6.5 Determination of surface resistance of the superconductor and ε′ and tan δ

of the standard sapphire rods................................................................................ 16

7 Uncertainty of the test method ....................................................................................... 17

7.1 Surface resistance ................................................................................................ 17

7.2 Temperature ......................................................................................................... 18

7.3 Specimen and holder support structure ................................................................. 18

7.4 Specimen protection ............................................................................................. 19

7.5 Uncertainty of surface resistance measured by standard two-resonator

method ................................................................................................................. 19

8 Test report ..................................................................................................................... 19

8.1 Identification of test specimen ............................................................................... 19

8.2 Report of R values ............................................................................................... 19

8.3 Report of test conditions ....................................................................................... 19

Annex A (informative) Additional information relating to Clauses 1 to 8 ................................ 20

A.1 Scope ................................................................................................................... 20

A.1.1 General ......................................................................................................... 20

A.1.2 Cylindrical cavity method [10] [17] ................................................................. 20

A.1.3 Parallel-plates resonator method [18] [19] ..................................................... 20

A.1.4 Microstrip-line resonance method [20] [21] .................................................... 20

A.1.5 Dielectric resonator method [22] [23] [24] [25] ............................................... 20

A.1.6 Image-type dielectric resonator method [26] [27] ........................................... 21

A.1.7 Two-resonator method [28] [29] ..................................................................... 22

A.2 Requirements ....................................................................................................... 22

A.3 Theory and calculation equations .......................................................................... 22

A.4 Apparatus ............................................................................................................. 25

A.5 Dimensions of the standard sapphire rods ............................................................ 26

A.6 Dimension of the closed type resonator ................................................................ 28

A.7 Sapphire rod reproducibility .................................................................................. 30

A.8 Test results ........................................................................................................... 30

A.9 Reproducibility of measurement method ............................................................... 31

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IEC 61788-7:2020 © IEC 2020 – 3 –

A.10 tan δ deviation effect of sapphire rods on surface resistance ................................ 32

Annex B (informative) Evaluation of relative combined standard uncertainty for surface

resistance measurement ....................................................................................................... 34

B.1 Practical surface resistance measurement ............................................................ 34

B.2 Determination of surface resistance of the superconductor ................................... 35

B.3 Combined standard uncertainty ............................................................................. 36

B.3.1 General ......................................................................................................... 36

B.3.2 Calculation of c to c (12 GHz resonance at 20 K) ........................................ 36

2 5

B.3.3 Determination of u to u ................................................................................ 37

1 5

B.3.4 Combined relative standard uncertainty ......................................................... 39

Bibliography .......................................................................................................................... 41

Figure 1 – Schematic diagram of measurement system for temperature dependence of

R using a cryocooler .............................................................................................................. 9

Figure 2 – Typical measurement apparatus for R ................................................................. 11

Figure 3 – Insertion attenuation, IA, resonant frequency, f , and half power bandwidth,

∆f, measured at T kelvin ........................................................................................................ 14

Figure 4 – Reflection scattering parameters (S and S ) ..................................................... 16

11 22

Figure 5 – Term definitions in Table 4 ................................................................................... 18

Figure A.1 – Schematic configuration of several measurement methods for the surface

resistance ............................................................................................................................. 21

Figure A.2 – Configuration of a cylindrical dielectric rod resonator short-circuited at

both ends by two parallel superconductor films deposited on dielectric substrates ................ 23

Figure A.3 – Computed results of the u-v and W-v relations for TE mode .......................... 24

01p

Figure A.4 – Configuration of standard dielectric rods for measurement of R and tan δ ........ 25

Figure A.5 – Three types of dielectric resonators .................................................................. 26

Figure A.6 – Mode chart to design TE resonator short-circuited at both ends by
011

parallel superconductor films [28] ......................................................................................... 27

Figure A.7 – Mode chart to design TE resonator short-circuited at both ends by
013

parallel superconductor films [28] ......................................................................................... 28

Figure A.8 – Mode chart for TE closed-type resonator [28] ............................................... 29

011

Figure A.9 – Mode chart for TE closed-type resonator [28] ............................................... 30

013
Figure A.10 – Temperature-dependent R of YBCO film with a thickness of 500 nm

and size of 25 mm square ..................................................................................................... 31

Figure A.11 – Temperature dependent R of YBCO film when R was measured three
s s

times..................................................................................................................................... 32

Figure B.1 – Schematic diagram of TE and TE mode resonance .................................. 34

011 013

Figure B.2 – Typical frequency characteristics of TE mode resonance ............................. 35

011
Figure B.3 – Frequency characteristics of a resonator approximated by a Lorentz

distribution ............................................................................................................................ 39

Table 1 – Typical dimensions of pairs of single-crystal sapphire rods for 12 GHz,

18 GHz and 22 GHz .............................................................................................................. 12

Table 2 – Dimensions of superconductor film for 12 GHz, 18 GHz, and 22 GHz .................... 13

Table 3 – Specifications for vector network analyzer ............................................................. 17

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SIST EN IEC 61788-7:2020
– 4 – IEC 61788-7:2020 © IEC 2020

Table 4 – Specifications for sapphire rods ............................................................................ 17

Table A.1 – Standard deviation of the surface resistance calculated from the results of

Figure A.11 ........................................................................................................................... 32

Table A.2 – Relationship between x, defined by Equation (A.12), and y, defined by

Equation (A.13) ..................................................................................................................... 33

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SIST EN IEC 61788-7:2020
IEC 61788-7:2020 © IEC 2020 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
SUPERCONDUCTIVITY –
Part 7: Electronic characteristic measurements –
Surface resistance of high-temperature
superconductors at microwave frequencies
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

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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

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3) IEC Publications have the form of recommendations for international use and are accepted by IEC National

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6) All users should ensure that they have the latest edition of this publication.

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members of its technical committees and IEC National Committees for any personal injury, property damage or

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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 61788-7 has been prepared by IEC technical committee 90:

Superconductivity.

This third edition cancels and replaces the second edition, published in 2006. This edition

constitutes a technical revision.

This edition includes the following significant technical changes with respect to the previous

edition:

a) informative Annex B, relative combined standard uncertainty for surface resistance

measurement has been added;
b) precision and accuracy statements have been converted to uncertainty;
c) reproducibility in surface resistant measurement has been added.
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SIST EN IEC 61788-7:2020
– 6 – IEC 61788-7:2020 © IEC 2020
The text of this International Standard is based on the following documents:
FDIS Report on voting
90/447/FDIS 90/452/RVD

Full information on the voting for the approval of this International Standard can be found in the

report on voting indicated in the above table.

This document 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 document 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 document will be
• reconfirmed;
• withdrawn;
• replaced by a revised edition, or
• amended.

IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates

that it contains colours which are considered to be useful for the correct understanding

of its contents. Users should therefore print this document using a colour printer.

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SIST EN IEC 61788-7:2020
IEC 61788-7:2020 © IEC 2020 – 7 –
INTRODUCTION

Since the discovery of some Perovskite-type Cu-containing oxides, extensive research and

development (R & D) work on high-temperature superconductors (HTS) has been, and is being,

done worldwide, and its application to high-field magnet machines, low-loss power transmission,

electronics and many other technologies is in progress.

In various fields of electronics, especially in telecommunication fields, microwave passive

devices such as filters using HTS are being developed and are undergoing on-site testing

[1] [2].

Superconductor materials for microwave resonators [3], filters [4], antennas [5] and delay

lines [6] have the advantage of very low loss characteristics. The parameters of superconductor

materials needed for the design of microwave low loss components are the surface resistance,

(R ) and the temperature dependence of the R . Knowledge of this parameter is of primary

s s

importance for the development of new materials on the supplier side and for the design of

superconductor microwave components on the customer side.

R of high quality HTS films is generally several orders of magnitude lower than that of normal

metals [7] [8] [9] [10], which has increased the need for a reliable characterization technique to

measure this property. Traditionally, the R of niobium or any other low-temperature

superconducting material was measured by first fabricating an entire three-dimensional

resonant cavity and then measuring its Q-value [11]. The R could be calculated by solving the

electro-magnetic field (EM) distribution inside the cavity. Another technique involves placing a

small sample inside a larger cavity. This technique has many forms but usually involves the

uncertainty introduced by extracting the loss contribution due to the HTS films from the

experimentally measured total loss of the cavity.

The best HTS samples are epitaxial films grown on flat crystalline substrates and no high-quality

films have been grown on any curved surface so far. What is needed is a technique that: can

use these small flat samples; requires no sample preparation; does not damage or change the

film; is highly repeatable; has great sensitivity (down to 1/1 000 the R of copper); has great

dynamic range (up to the R of copper); can reach high internal powers with only modest input

powers; and has broad temperature coverage (4,2 K to 150 K).

The dielectric resonator method is selected among several methods to determine the surface

resistance at microwave frequencies because it is considered to be the most popular and

practical at present. Especially, the sapphire resonator is an excellent tool for measuring

the R of HTS materials [12] [13] [14]

The test method given in this document can also be applied to other superconductor bulk plates

materials.
including low T

This document is intended to provide an appropriate and agreeable technical base for the time

being to engineers working in the fields of electronics and superconductivity technology.

The test method covered in this document is based on the VAMAS (Versailles Project on

Advanced Materials and Standards) pre-standardization work on the thin film properties of

superconductors.
___________
Numbers in square brackets refer to the bibliography.
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SIST EN IEC 61788-7:2020
– 8 – IEC 61788-7:2020 © IEC 2020
SUPERCONDUCTIVITY –
Part 7: Electronic characteristic measurements –
Surface resistance of high-temperature
superconductors at microwave frequencies
1 Scope
This part of IEC 61788 describes measurement of the surface resistance (R ) of

superconductors at microwave frequencies by the standard two-resonator method. The object

of measurement is the temperature dependence of R at the resonant frequency.
The applicable measurement range of R for this method is as follows:
– Frequency: 8 GHz < f < 30 GHz
– Measurement resolution: 0,01 mΩ at 10 GHz

The R data at the measured frequency, and that scaled to 10 GHz, assuming the f rule for

comparison, is reported.
2 Normative references

The following documents are referred to in the text in such a way that some or all of their content

constitutes requirements 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.

IEC 60050-815, International Electrotechnical Vocabulary (IEV) – Part 815: Superconductivity

3 Terms and definitions

For the purposes of this document, the terms and definitions given in IEC 60050-815 apply.

ISO and IEC maintain terminological databases for use in standardization at the following

addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
4 Requirements

The R of a superconductor film shall be measured by applying a microwave signal to a dielectric

resonator with the superconductor film specimen and then measuring the attenuation of the

resonator at each frequency. The frequency shall be swept around the resonant frequency as

the centre, and the attenuation–frequency characteristics shall be recorded to obtain

the Q- value, which corresponds to the loss.

The target relative combined standard uncertainty of this method is less than 20 % for the

measurement temperature range from 20 K to 80 K.
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SIST EN IEC 61788-7:2020
IEC 61788-7:2020 © IEC 2020 – 9 –

It is the responsibility of the user of this document to establish appropriate safety and health

practices and to determine the applicability of regulatory limitations prior to use.

Hazards exist in this type of measurement. The use of a cryogenic system is essential to cool

the superconductors to allow transition into the superconducting state. Direct contact of skin

with cold apparatus components can cause immediate freezing, as can direct contact with a

spilled cryogen. The use of an RF generator is also essential to measure high-frequency

properties of materials. If its power is too high, direct contact to human bodies can cause an

immediate burn.
5 Apparatus
5.1 Measurement system

Figure 1 shows a schematic diagram of the system required for the microwave measurement.

The system consists of a network analyzer system for transmission measurement, a

measurement apparatus, and a thermometer for monitoring the measuring temperature

...