Magnetic materials - Part 13: Methods of measurement of resistivity, density and stacking factor of electrical steel strip and sheet

IEC 60404-13:2018 specifies the methods used for determining the resistivity, density and stacking factor of grain-oriented and non-oriented electrical steel strip and sheet. These quantities are necessary to establish the physical characteristics of the material. Moreover, the density is necessary to allow specified values of the magnetic polarization, resistivity and stacking factor to be determined. Since these properties are functions of temperature, the measurements will be made at an ambient temperature of (23 ±5) °C except when specified in this document. This edition includes the following significant technical changes with respect to the previous edition:  the sequence of the density and resistivity sections is changed and the title of the document revised to reflect this; the van-der-Pauw method (Method R2) is also applicable to Epstein strip specimens; the gas pyknometer method is introduced, and the liquid immersion method and the calculation method based on the chemical composition are quoted; the requirements of the stacking factor section, such as the tolerance of the dimensions of the test specimen and the repeatability of measurement, are changed; an example of the apparatus for determination of the resistivity using a rectangular sheet, which was previously part of the main body of the text, is moved to constitute informative Annex A; an example of the determination of the density by using the gas pyknometer method is added as an informative Annex B; an example of the determination of density based on the calculation of silicon and aluminium contents is added as an informative Annex C.

Magnetische Werkstoffe - Teil 13: Verfahren der Messung des spezifischen elektrischen Widerstandes, der Dichte und des Stapelfaktors von Elektroband und -blech

Matériaux magnétiques - Partie 13: Méthodes de mesure de la résistivité, de la masse volumique et du facteur de foisonnement des bandes et tôles en acier électrique

L'IEC 60404-13:2018 spécifie les méthodes utilisées pour déterminer la résistivité, la masse volumique et le facteur de foisonnement des bandes et tôles en acier électrique à grains orientés et à grains non orientés. Ces grandeurs sont nécessaires pour établir les caractéristiques physiques du matériau. De plus, la masse volumique est nécessaire pour déterminer les valeurs spécifiées pour la polarisation magnétique, la résistivité et le facteur de foisonnement. Comme ces propriétés dépendent de la température, les mesures seront prises à une température ambiante de (23 ± 5) °C sauf spécification contraire dans le présent document. Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:  l'ordre des articles traitant de la masse volumique et de la résistivité a été modifié, ce qui a nécessité une révision du titre du document afin de refléter ce changement; la méthode Van der Pauw (Méthode R2) est également applicable aux bandes Epstein; la méthode utilisant un pycnomètre à gaz a été introduite, et la méthode en milieu liquide ainsi que la méthode de calcul basée sur la composition chimique sont citées; les exigences de l'article traitant du facteur de foisonnement, comme la tolérance concernant les dimensions de l'éprouvette d'essai et la répétabilité des mesures, ont été modifiées; un exemple de l'appareillage utilisé pour la détermination de la résistivité sur tôle rectangulaire, qui était intégré au corps du document dans l'édition précédente, a été déplacé pour former l'Annexe A informative; un exemple de détermination de la masse volumique par la méthode utilisant un pycnomètre à gaz a été ajouté à l'Annexe B informative; un exemple de détermination de la masse volumique par le calcul des teneurs en silicium et en aluminium a été ajouté à l'Annexe C informative.

Magnetni materiali - 13. del: Metode za meritve upornosti, gostote in skladnega faktorja električnih jeklenih trakov in pločevine (IEC 60404-13:2018)

Ta del standarda IEC 60404 določa metode, ki se uporabljajo za določanje upornosti, gostote ter skladnega faktorja zrnato orientiranih in neorientiranih električnih jeklenih trakov in pločevine. Te količine so potrebne za ugotavljanje fizikalnih lastnosti materiala. Podatek o gostoti pa je potreben tudi za ugotavljanje specifičnih vrednosti magnetne polarizacije, upornosti in skladnega faktorja.
Ker te lastnosti temeljijo na temperaturi, je treba meritve opraviti pri temperaturi okolja (23 ±5) °C, razen če je to določeno v tem dokumentu.

General Information

Status
Published
Publication Date
25-Oct-2018
Current Stage
6060 - Document made available
Due Date
17-Dec-2018

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SLOVENSKI STANDARD
SIST EN IEC 60404-13:2019
01-januar-2019
1DGRPHãþD
SIST EN 60404-13:2008
0DJQHWQLPDWHULDOLGHO0HWRGH]DPHULWYHXSRUQRVWLJRVWRWHLQVNODGQHJD
IDNWRUMDHOHNWULþQLKMHNOHQLKWUDNRYLQSORþHYLQH ,(&
Magnetic materials - Part 13: Methods of measurement of resistivity, density and
stacking factor of electrical steel strip and sheet (IEC 60404-13:2018)

Magnetische Werkstoffe - Teil 13: Verfahren der Messung des spezifischen elektrischen

Widerstandes, der Dichte und des Stapelfaktors von Elektroband und -blech (IEC 60404-

13:2018)
Magnetic materials - Part 13: Methods of measurement of density, resistivity and
stacking factor of electrical steel sheet and strip (IEC 60404-13:2018)
Ta slovenski standard je istoveten z: EN IEC 60404-13:2018
ICS:
17.220.20 0HUMHQMHHOHNWULþQLKLQ Measurement of electrical
PDJQHWQLKYHOLþLQ and magnetic quantities
29.030 Magnetni materiali Magnetic materials
SIST EN IEC 60404-13:2019 en

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

---------------------- Page: 1 ----------------------
SIST EN IEC 60404-13:2019
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SIST EN IEC 60404-13:2019
EUROPEAN STANDARD EN IEC 60404-13
NORME EUROPÉENNE
EUROPÄISCHE NORM
October 2018
ICS 17.220.20; 29.030 Supersedes EN 60404-13:2007
English Version
Magnetic materials - Part 13: Methods of measurement of
resistivity, density and stacking factor of electrical steel strip and
sheet
(IEC 60404-13:2018)

Matériaux magnétiques - Partie 13: Méthodes de mesure Magnetische Werkstoffe - Teil 13: Verfahren der Messung

de la résistivité, de la masse volumique et du facteur de des spezifischen elektrischen Widerstandes, der Dichte und

foisonnement des bandes et tôles en acier électrique des Stapelfaktors von Elektroband und -blech

(IEC 60404-13:2018) (IEC 60404-13:2018)

This European Standard was approved by CENELEC on 2018-08-14. 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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,

Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, 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

© 2018 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.

Ref. No. EN IEC 60404-13:2018 E
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SIST EN IEC 60404-13:2019
EN IEC 60404-13:2018 (E)
European foreword

The text of document 68/574/CDV, future edition 2 of IEC 60404-13, prepared by IEC/TC 68

"Magnetic alloys and steels" was submitted to the IEC-CENELEC parallel vote and approved by

CENELEC as EN IEC 60404-13:2018.
The following dates are fixed:

• latest date by which the document has to be implemented at national (dop) 2019-05-14

level by publication of an identical national standard or by endorsement

• latest date by which the national standards conflicting with the (dow) 2021-08-14

document have to be withdrawn
This document supersedes EN 60404-13:2007.

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 60404-13:2018 was approved by CENELEC as a European

Standard without any modification.

In the official version, for Bibliography, the following notes have to be added for the standards

indicated:
ISO 1183-1:2012 NOTE Harmonized as EN ISO 1183-1:2012 (not modified)
ISO 2738:1999 NOTE Harmonized as EN ISO 2738:1999 (not modified)
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SIST EN IEC 60404-13:2019
EN IEC 60404-13:2018 (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 60050-121 - International Electrotechnical Vocabulary - Part 121: - -
Electromagnetism
IEC 60050-221 - International Electrotechnical Vocabulary. Chapter 221: - -
Magnetic materials and components

IEC 60404-2 - Magnetic materials - Part 2: Methods of measurement EN 60404-2 -

of the magneticproperties of electrical steel sheet and
strip by means of an Epstein frame
IEC 60404-3 - Magnetic materials - Part 3: Methods of measurement - -
of the magnetic properties of magnetic sheet and strip
by means of a single sheet tester

ISO 1183-3 - Plastics - Methods for determining the density of non- EN ISO 1183-3 -

cellular plastics - Part 3: Gas pyknometer method
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SIST EN IEC 60404-13:2019
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SIST EN IEC 60404-13:2019
IEC 60404-13
Edition 2.0 2018-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Magnetic materials –
Part 13: Methods of measurement of resistivity, density and stacking factor of
electrical steel strip and sheet
Matériaux magnétiques –
Partie 13: Méthodes de mesure de la résistivité, de la masse volumique et du
facteur de foisonnement des bandes et tôles en acier électrique
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 17.220.20; 29.030 ISBN 978-2-8322-5869-9

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 60404-13:2019
– 2 – IEC 60404-13:2018 © IEC 2018
CONTENTS

FOREWORD ........................................................................................................................... 4

1 Scope .............................................................................................................................. 6

2 Normative references ...................................................................................................... 6

3 Terms and definitions ...................................................................................................... 6

4 Determination of the resistivity......................................................................................... 7

4.1 General ................................................................................................................... 7

4.2 Principles of measurement ...................................................................................... 7

4.2.1 Method of determining ρ for an Epstein strip specimen (Method R1) ................ 7

4.2.2 Method of determining ρ for a rectangular sheet specimen (Method R2)

with supplementary remarks for strip specimen ................................................ 8

4.2.3 Determination of thickness d ............................................................................ 9

4.3 Test specimen ...................................................................................................... 10

4.3.1 Epstein strip specimen ................................................................................... 10

4.3.2 Rectangular sheet specimen .......................................................................... 10

4.4 Apparatus ............................................................................................................. 10

4.4.1 Common requirements for Method R1 and Method R2 ................................... 10

4.4.2 Requirements for Method R1 ......................................................................... 10

4.4.3 Requirements for Method R2 ......................................................................... 11

4.5 Measuring procedure ............................................................................................ 11

4.5.1 Determination of the thickness d of the test specimen .................................... 11

4.5.2 Procedure with strip specimen (Method R1) ................................................... 11

4.5.3 Procedure with rectangular sheet specimen (Method R2) .............................. 11

4.6 Reproducibility ...................................................................................................... 11

4.7 Test report ............................................................................................................ 12

5 Determination of the density .......................................................................................... 12

5.1 General ................................................................................................................. 12

5.2 Method based on the measurement of resistance (Method D1) ............................. 13

5.2.1 Principles of measurement ............................................................................ 13

5.2.2 Test specimen ............................................................................................... 14

5.2.3 Measuring procedure ..................................................................................... 14

5.2.4 Reproducibility ............................................................................................... 15

5.3 Gas pyknometer method (Method D2) ................................................................... 15

5.3.1 Principles of measurement ............................................................................ 15

5.3.2 Test specimen ............................................................................................... 15

5.3.3 Test apparatus .............................................................................................. 15

5.3.4 Measuring procedure ..................................................................................... 15

5.3.5 Reproducibility ............................................................................................... 15

5.4 Test report ............................................................................................................ 15

6 Determination of the stacking factor............................................................................... 16

6.1 General ................................................................................................................. 16

6.2 Test specimen ...................................................................................................... 16

6.3 Measuring procedure ............................................................................................ 16

6.4 Reproducibility ...................................................................................................... 17

6.5 Test report ............................................................................................................ 17

Annex A (informative) An example of the apparatus for the measurement of the

resistivity using a rectangular sheet specimen (Method R2) .................................................. 19

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IEC 60404-13:2018 © IEC 2018 – 3 –
Annex B (informative) An example of the determination of density using the gas

pyknometer method (Method D2) .......................................................................................... 20

B.1 Overview............................................................................................................... 20

B.2 Test specimen ...................................................................................................... 20

B.3 Apparatus ............................................................................................................. 21

B.4 Calibration ............................................................................................................ 21

B.5 Measuring procedure ............................................................................................ 21

B.6 Repeatability ......................................................................................................... 22

Annex C (informative) Calculation of density based on silicon and aluminium content

(Method D4) .......................................................................................................................... 23

Bibliography .......................................................................................................................... 24

Figure 1 – Circuit for the measurement of resistance of an Epstein strip specimen

(Method R1) ............................................................................................................................ 7

Figure 2 – Circuit for the measurement of resistance of a rectangular sheet specimen

(Method R2) ............................................................................................................................ 8

Figure 3 – Experimental data and the regression line of the density ρ against the

product ρ ·ρ for non-oriented electrical steel sheet [6] ......................................................... 13

Figure 4 – Schematic diagram of stacking specimen and rams .............................................. 17

Figure A.1 – Schematic cross-sectional view of the arrangement of the contact holder ......... 19

Figure B.1 – Diagram illustrating the two-chamber pressure gas pyknometer ........................ 21

Table B.1 – Number of test discs of diameter 36 mm ............................................................ 20

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SIST EN IEC 60404-13:2019
– 4 – IEC 60404-13:2018 © IEC 2018
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
MAGNETIC MATERIALS –
Part 13: Methods of measurement of resistivity, density
and stacking factor of electrical steel strip and sheet
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 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

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 60404-13 has been prepared by IEC Technical Committee 68:

Magnetic alloys and steels.

This second edition cancels and replaces the first edition published in 1995 and constitutes a

technical revision.

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

edition:

a) the sequence of the density and resistivity sections is changed and the title of the

document revised to reflect this;

b) the van-der-Pauw method (Method R2) is also applicable to Epstein strip specimens;

c) the gas pyknometer method is introduced, and the liquid immersion method and the

calculation method based on the chemical composition are quoted;
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SIST EN IEC 60404-13:2019
IEC 60404-13:2018 © IEC 2018 – 5 –

d) the requirements of the stacking factor section, such as the tolerance of the dimensions of

the test specimen and the repeatability of measurement, are changed;

e) an example of the apparatus for determination of the resistivity using a rectangular sheet,

which was previously part of the main body of the text, is moved to constitute informative

Annex A;

f) an example of the determination of the density by using the gas pyknometer method is

added as an informative Annex B;

g) an example of the determination of density based on the calculation of silicon and

aluminium contents is added as an informative Annex C.
The text of this International Standard is based on the following documents:
CDV Report on voting
68/574/CDV 68/586A/RVC

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 the parts in the IEC 60404 series, under the general title Magnetic materials, can

be found on the IEC web site.

The committee has decided that the contents of this document will remain unchanged until the

stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to

the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
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SIST EN IEC 60404-13:2019
– 6 – IEC 60404-13:2018 © IEC 2018
MAGNETIC MATERIALS –
Part 13: Methods of measurement of resistivity, density
and stacking factor of electrical steel strip and sheet
1 Scope

This part of IEC 60404 specifies the methods used for determining the resistivity, density and

stacking factor of grain-oriented and non-oriented electrical steel strip and sheet. These

quantities are necessary to establish the physical characteristics of the material. Moreover,

the density is necessary to allow specified values of the magnetic polarization, resistivity and

stacking factor to be determined.

Since these properties are functions of temperature, the measurements will be made at an

ambient temperature of (23 ±5) °C except when specified in this document.
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 60050-121, International Electrotechnical Vocabulary – Part 121: Electromagnetism

IEC 60050-221, International Electrotechnical Vocabulary – Chapter 221: Magnetic materials

and components
IEC 60404-2, Magnetic materials – Part 2: Methods of measurement of the magnetic
properties of electrical steel sheet and strip by means of an Epstein frame
IEC 60404-3, Magnetic materials – Part 3: Methods of measurement of the magnetic
properties of magnetic sheet and strip by means of a single sheet tester

ISO 1183-3, Plastics – Methods for determining the density of non-cellular plastics – Part 3:

Gas pyknometer method
3 Terms and definitions

For the purposes of this document, the terms and definitions given in IEC 60050-121,

IEC 60050-221 and ISO 1183-3 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
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SIST EN IEC 60404-13:2019
IEC 60404-13:2018 © IEC 2018 – 7 –
4 Determination of the resistivity
4.1 General

Two methods for the determination of the resistivity of a test specimen are described in this

document; Method R1 using an Epstein strip specimen, and Method R2 using a rectangular

sheet specimen.

NOTE Method R2 is based on the van-der-Pauw (VDP) method [1] which is based on the theory of conformal

mapping of two-dimensional fields. For a body of uniform thickness and arbitrary shape, an exact mathematical

formula exists for the resistivity determined from the voltage to current ratio obtained using four contacts. The

formula is simplified when specimens and contact positions are highly symmetrical. Method R2 is particularly

appropriate for rectangular sheet specimens.

The method of determination of the resistivity ρ, based on the measurement of the geometric

dimensions of the test specimen including the thickness, can be applied to all types of

material specimens. However, the method for further use to determine the density ρ in

accordance with 5.2 is restricted to the materials as specified in 5.1.
4.2 Principles of measurement
4.2.1 Method of determining ρ for an Epstein strip specimen (Method R1)

The circuit for the measurement of the resistance of an Epstein strip specimen shall be

connected as shown in Figure 1. Two electrical contacts A and B shall be arranged on either

end of the shorter sides of the test specimen to supply a homogeneous current through the

test specimen in the longitudinal direction. Two electrical contacts, C and D, located inside

the contacts A and B shall be arranged on a longer side edge of the test specimen to measure

the voltage over the length l . It is not necessary to remove the oxide layer or other insulating

coatings because the contacts are made at the cut edges of the specimen.
Specimen
Power
S U
supply
IEC
Key
A, B, C, D electrical contact I current flowing between A and B
A DC ammeter S switch for current reversal
V DC voltmeter voltage between C and D
l distance between C and D
Figure 1 – Circuit for the measurement of resistance of
an Epstein strip specimen (Method R1)
____________
Numbers in square brackets refer to the Bibliography.
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SIST EN IEC 60404-13:2019
– 8 – IEC 60404-13:2018 © IEC 2018

If a current flows homogeneously through the test specimen, the resistance R of the material

over the length l of the Epstein strip specimen shall be determined according to Ohm’s law

as follows:
R = (1)
where

R is the resistance of the material over the length l between the contacts C and D,

in ohms;
U is the voltage between the contacts C and D, in volts;
I is the current flowing between the contacts A and B, in amperes.
The resistivity ρ shall be determined from the following formula:
R ∙ b ∙ d
ρ = (2)
where
ρ is the resistivity of the material of the test specimen, in ohm metres;
b is the width of the test specimen, in metres;
d is the thickness of the test specimen without an insulation layer, in metres;
l is the distance between the contacts C and D, in metres.
4.2.2 Method of determining ρ for a rectangular sheet specimen (Method R2) with
supplementary remarks for strip specimen

The circuit for the measurement of the resistance of a square-shaped or rectangular sheet

specimen shall be connected as shown in Figure 2. Four electrical contacts A, B, C and D

shall be arranged symmetrically at the centre of each edge of the test specimen. The contacts

A, B, C and D shall be as small as possible. With a current flowing through the contacts A and

B, the voltage between the contacts C and D shall be measured. It is not necessary to remove

oxide layer or other insulating coatings because the contacts are made at the cut edges of the

specimens.
I A
AB 1
Power
supply A
Specimen
IEC
Key
A, B, C, D electrical contact I current flowing between A and B
A DC ammeter S switch for current reversal
V DC voltmeter U voltage between C and D
1 CD
Figure 2 – Circuit for the measurement of resistance of
a rectangular sheet specimen (Method R2)
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SIST EN IEC 60404-13:2019
IEC 60404-13:2018 © IEC 2018 – 9 –
The resistance R shall be calculated according to the following formula:
AB,CD
R = (3)
AB,CD
where
R is the resistance measured between the contacts C and D, in ohms;
AB,CD
U is the voltage between the contacts C and D, in volts;
I is the current flowing between the contacts A and B, in amperes.
Correspondingly, the resistance R shall be obtained from the voltage between the
BC,DA
contacts D and A and the current flowing through the contacts B and C.

On the basis of the theory of conformal mapping of two-dimensional fields [1], for a body of

uniform thickness and arbitrary shape, the following formula holds:
π ∙ d R + R
AB, CD BC, DA
ρ = ∙ ∙ F (4)
ln 2 2
where
ρ is the resistivity of the material of the test specimen, in ohm metres;
d is the thickness of the test specimen without insulation layer, in metres;
AB, CD
F is a function of the ratio only.
BC, DA
AB, CD

If the ratio is close to unity, the function F becomes 1, so that it can be omitted [1]. To

BC, DA

ensure that this ratio is close to unity, the contacts shall be arranged symmetrically at the

centres of the edges of the rectangular sheet specimen as shown in Figure 2.

Method R2 can also be applied to Epstein strip specimen offering the advantage that the

same base plate and contact holders (see Annex A) as for the rectangular sheet specimens

can be used, in this case, to obtain a reliable result of the measurement, a certain number

(e.g. > 10) of Epstein strip specimens should be tested, and the average should be taken as

the result.

NOTE It has been shown that Method R2 (van der Pauw method [1]) is equivalent to Method R1, within limits

which are lower than the dispersion between individual strip specimens of one grade of material [2]. The Method

R2 has the advantages of versatility of specimen shape [3].
4.2.3 Determination o
...

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