SIST EN 60404-2:2002
(Main)Magnetic materials -- Part 2: Methods of measurement of the magnetic properties of electrical steel sheet and strip by means of an Epstein frame
Magnetic materials -- Part 2: Methods of measurement of the magnetic properties of electrical steel sheet and strip by means of an Epstein frame
This part of IEC 404 is applicable to grain oriented and non-oriented electrical sheet and strip
for a.c. measurements of magnetic properties at frequencies up to 400 Hz and for d.c.
magnetic measurements.
The object of this part is to define the general principles and the technical details of the
measurement of the magnetic properties of electrical steel sheet and strip by means of an
Epstein frame.
The Epstein frame is applicable to test specimens obtained from electrical steel sheets and
strips of any grade. The a.c. magnetic characteristics are determined for sinusoidal induced
voltages, for specified peak values of magnetic polarization and for a specified frequency.
The measurements are to be made at an ambient temperature of (23 ± 5) °C on test specimens
which have first been demagnetized.
Measurements at higher frequencies are to be made in accordance with IEC 404-10.
NOTE — Throughout this standard the term "magnetic polarization" is used as defined in IEC 50(221). In
some standards of the IEC 404 series, the term "magnetic flux density" was used.
Magnetische Werkstoffe -- Teil 2: Verfahren zur Bestimmung der magnetischen Eigenschaften von Elektroblech und -band mit Hilfe eines Epsteinrahmens
Matériaux magnétiques -- Partie 2: Méthodes de mesure des propriétés magnétiques des tôles et bandes magnétiques au moyen d'un cadre Epstein
S'applique aux tôles et bandes magnétiques à grains orientés et non orientés, pour le mesurage des propriétés magnétiques en courant alternatif jusqu'à la fréquence de 400 Hz, et pour les mesures magnétiques en courant continu. Définit les principes généraux et les détails techniques du mesurage des propriétés magnétiques des tôles et bandes magnétiques au moyen d'un cadre Epstein. Les caractéristiques magnétiques en courant alternatif sont déterminées pour des tensions induites sinusoïdales, pour des valeurs crêtes particulières de la polarisation magnétique et pour une fréquence spécifiée.
Magnetic materials - Part 2: Methods of measurement of the magnetic properties of electrical steel sheet and strip by means of an Epstain frame (IEC 60404-2:1996)
Ta del standarda IEC 404 se uporablja za zrnato orientirano in neorientirano elektropločevino ter trakove za merjenje magnetnih lastnosti pri izmeničnem toku in frekvencah do 400 Hz ter za magnetne meritve pri enosmernem toku.
Namen tega dela je opredeliti splošna načela in tehnične podrobnosti za merjenje magnetnih lastnosti električnih jeklenih pločevin in trakov s pomočjo Epsteinovega okvira.
Epsteinov okvir se uporablja za preskusne vzorce, pridobljene iz elektropločevine in trakov katerega koli razreda. Magnetne lastnosti pri izmeničnem toku se določijo za sinusoidno inducirane napetosti, za določene najvišje vrednosti magnetne polarizacije in za določeno frekvenco.
Meritve je treba opraviti pri sobni temperaturi (23 ± 5) °C na preskusnih vzorcih, ki so bili pred tem razmagneteni.
Meritve pri višjih frekvencah je treba opraviti v skladu s standardom IEC 404-10.
OPOMBA: V tem standardu je izraz »magnetna polarizacija« uporabljen tako, kot je opredeljen v standardu IEC 50(221). V nekaterih standardih iz skupine standardov IEC 404 je bil uporabljen izraz »gostota magnetnega pretoka«.
General Information
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Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN 60404-2:2002
01-september-2002
Magnetic materials - Part 2: Methods of measurement of the magnetic properties
of electrical steel sheet and strip by means of an Epstain frame (IEC 60404-2:1996)
Magnetic materials -- Part 2: Methods of measurement of the magnetic properties of
electrical steel sheet and strip by means of an Epstein frame
Magnetische Werkstoffe -- Teil 2: Verfahren zur Bestimmung der magnetischen
Eigenschaften von Elektroblech und -band mit Hilfe eines Epsteinrahmens
Matériaux magnétiques -- Partie 2: Méthodes de mesure des propriétés magnétiques
des tôles et bandes magnétiques au moyen d'un cadre Epstein
Ta slovenski standard je istoveten z: EN 60404-2:1998
ICS:
17.220.20 0HUMHQMHHOHNWULþQLKLQ Measurement of electrical
PDJQHWQLKYHOLþLQ and magnetic quantities
29.030 Magnetni materiali Magnetic materials
SIST EN 60404-2:2002 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST EN 60404-2:2002
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SIST EN 60404-2:2002
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SIST EN 60404-2:2002
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SIST EN 60404-2:2002
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SIST EN 60404-2:2002
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SIST EN 60404-2:2002
NORME CEI
INTERNATIONALE I E C
404-2
INTERNATIONAL
Troisième édition
STANDARD
Third edition
1996-03
Matériaux magnétiques —
Partie 2:
Méthodes de mesure des propriétés
magnétiques des tôles et bandes magnétiques
au moyen d'un cadre Epstein
Magnetic materials —
Part 2:
Methods of measurement of the magnetic
properties of electrical steel sheet and strip
by means of an Epstein frame
© CEI 1996 Droits de reproduction réservés —
Copyright — all rights reserved
Aucune partie de cette publication ne peut être reproduite ni
No part of this publication may be reproduced or util¢ed in
utilisée sous quelque forme que ce soit et par aucun pro- any form or by any means, electronic or mechanical,
cédé, électronique ou mécanique, y compris la photocopie et including photocopying and microfilm, without permission
les microfilms, sans l'accord écrit de l'éditeur. in writing from the publisher.
Bureau Central de la Commission Electrotechnique Internationale 3, rue de Varembé Genève, Suisse
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ayiiapoAHaa 3iieic poTexHH4ecnaR HOMHCCHR
• Pour prix, voir catalogue en vigueur •
For price, see current catalogue
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SIST EN 60404-2:2002
404-2 © IEC:1996 - 3 -
CONTENTS
Page
FOREWORD 5
Clause
1 Scope and object 7
2 Normative references 7
3 General principles of a.c. measurements 9
3.1 Principle of the 25 cm Epstein frame method 9
3.2 Test specimen 9
3.3 The 25 cm Epstein frame 11
3.4 Air flux compensation 13
3.5 Power supply 13
3.6 Voltage measurement 15
3.7 Frequency measurement 15
3.8 Power measurement 15
4 Procedure for the measurement of the specific total loss 15
4.1 Preparation for measurement 15
4.2 Adjustment of power supply 17
4.3 Measurement of power 19
4.4 Determination of the specific total loss 19
4.5 Reproducibility of the specific total loss measurement 19
5 Procedure for the determination of the peak value of magnetic polarization,
r.m.s. value of magnetic field strength, peak value of magnetic field strength
and specific apparent power 21
5.1 Test specimen 21
5.2 Principle of measurement 21
5.3 Reproducibility 25
6 General principles of d.c. measurements 25
6.1 Principle of the 25 cm Epstein frame method 25
6.2 Test specimen 25
6.3 The 25 cm Epstein frame 25
6.4 Air flux compensation 25
6.5 Power supply 27
6.6 Apparatus accuracy 27
7 Procedure for the d.c. measurement of the magnetic polarization 27
7.1 Preparation for measurement 27
7.2 Determination of the magnetic polarization 27
7.3 Determination of the magnetic hysteresis loop 29
7.4 Reproducibility of the measurement of the magnetic polarization 29
8 Test report 29
Figures 31
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SIST EN 60404-2:2002
404-2 © IEC:1996 – 5–
INTERNATIONAL ELECTROTECHNICAL COMMISSSION
MAGNETIC MATERIALS -
Part 2: Methods of measurement of the magnetic properties
of electrical steel sheet and strip by means of an Epstein frame
FOREWORD
1) The IEC (International Electrotechnical Commission) is a worldwide organization for standardization
comprising all national electrotechnical committees (IEC National Committees). The object of the 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, the IEC publishes International Standards. 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. The 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 the 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 National Committees.
3) The documents produced have the form of recommendations for international use and are published in the
form of standards, technical repo rt
s or guides and they are accepted by the National Committees in that
sense.
4)
In order to promote international unification, IEC National Committees undertake to apply IEC International
Standards transparently to the maximum extent possible in their national and regional standards. Any
divergence between the IEC Standard and the corresponding national or regional standard shall be clearly
indicated in the latter.
5)
The IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with one of its standards.
6)
Attention is drawn to the possibility that some of the elements of this International Standard may be the
subject of patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 404-2 has been prepared by IEC technical committee 68: Magnetic
alloys and steels.
This third edition cancels and replaces the second edition published in 1978 and constitutes a
technical revision.
This standard supersedes chapters I, II, IV and V of IEC 404-2: 1978.
The standard IEC 404-11 supersedes chapter VIII of IEC 404-2: 1978.
The standard IEC 404-13 supersedes chapters VI, VII and IX of IEC 404-2: 1978.
Chapter III of IEC 404-2: 1978 is cancelled.
The text of this standard is based on the following documents:
FDIS Report on voting
68/119/FDIS 68/135/RV D
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
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SIST EN 60404-2:2002
404-2 © IEC:1996 - 7 -
MAGNETIC MATERIALS -
Part 2: Methods of measurement of the magnetic properties
of electrical steel sheet and strip by means of an Epstein frame
1 Scope and object
This part of IEC 404 is applicable to grain oriented and non-oriented electrical sheet and strip
for a.c. measurements of magnetic properties at frequencies up to 400 Hz and for d.c.
magnetic measurements.
The object of this part is to define the general principles and the technical details of the
measurement of the magnetic properties of electrical steel sheet and strip by means of an
Epstein frame.
The Epstein frame is applicable to test specimens obtained from electrical steel sheets and
strips of any grade. The a.c. magnetic characteristics are determined for sinusoidal induced
voltages, for specified peak values of magnetic polarization and for a specified frequency.
The measurements are to be made at an ambient temperature of (23 ± 5) °C on test specimens
which have first been demagnetized.
Measurements at higher frequencies are to be made in accordance with IEC 404-10.
NOTE — Throughout this standard the term "magnetic polarization" is used as defined in IEC 50(221). In
some standards of the IEC 404 series, the term "magnetic flux density" was used.
2 Normative references
The following normative documents contain provisions which, through reference in this text,
constitute provisions of this part of IEC 404. At the time of publication, the editions indicated
were valid. All normative documents are subject to revision, and parties to agreements based
on this part of IEC 404 are encouraged to investigate the possibility of applying the most recent
editions of the normative documents listed below. Members of IEC and ISO maintain registers
of currently valid International Standards.
IEC 50(221): 1990, International Electrotechnical Vocabulary (IEV) - Chapter 221: Magnetic
materials and components
IEC 404-4: 1995, Magnetic materials - Part 4: Methods of measurement of d.c. magnetic
properties of iron and steel
IEC 404-8-2: 1985, Magnetic materials - Part 8: Specifications for individual materials -
Section Two: Specification for cold-rolled magnetic alloyed steel strip delivered in the semi-
processed state
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SIST EN 60404-2:2002
404-2 © IEC:1996 - 9-
IEC 404-8-3: 1985,
Magnetic materials - Part 8: Specifications for individual materials -
Section Three: Specification for cold-rolled magnetic non-alloyed steel strip delivered in the
semi-processed state
IEC 404-8-4: 1986, Magnetic materials - Part 8: Specifications for individual materials -
Section Four: Specification for cold-rolled non-oriented magnetic steel sheet and strip
IEC 404-8-7: 1988, Magnetic materials - Part
8: Specifications for individual materials -
Section Seven: Specification for grain oriented magnetic steel sheet and strip
IEC 404-10: 1988, Magnetic materials - Part 10: Methods of measurement of magnetic
properties of magnetic steel sheet and strip at medium frequencies
IEC 404-13: 1995, Magnetic materials - Part
13: Methods of measurement of density,
resistivity and stacking factor of electrical steel sheet and strip
3 General principles of a.c. measurements
3.1 Principle of the 25 cm Epstein frame method
The 25 cm Epstein frame which comprises a primary winding, a secondary winding and the
specimen to be tested as a core, forms an unloaded transformer whose characteristics are
measured by the method described in the following subclauses.
3.2 Test specimen
The strips to be tested are assembled in a square, having double-lapped joints (see figure 1),
thus forming four branches of equal length and equal cross-sectional area.
The strips shall be sampled in accordance with the appropriate product standard in the
IEC 404-8 series.
They shall be cut by a method which will produce substantially burr-free edges and, if so
specified, heat treated in accordance with the corresponding product standard. They shall have
the following dimensions:
- width b = 30 mm t 0,2 mm;
- length 280 mm <_ l 5 320 mm.
The lengths of the strips shall be equal within a tolerance of t0,5 mm.
When strips are cut parallel or normal to the direction of rolling, the edge of the parent sheet
shall be taken as the reference direction.
The following tolerances shall apply for the angle between the specified and actual direction of
cutting:
±-1° for grain oriented steel sheet;
t5° for non-oriented steel sheet.
Only flat strips shall be used. Measurements shall be made without additional insulation.
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SIST EN 60404-2:2002
404-2 © IEC:1996 — 11 —
The number of strips comprising the test specimen shall be a multiple of four and is specified in
the corresponding product standard. However, the active mass of the test specimen (see
equation (1)) shall be at least 240 g for strips 280 mm long.
3.3 The 25 cm Epstein frame
The 25 cm Epstein frame (hereinafter referred to as the Epstein frame) shall consist of four
coils into which the strips making up the test specimen are inserted (see figure 2).
A mutual inductor for air flux compensation is included with the Epstein frame.
The winding formers supporting the coils are made of hard insulating material, such as phenolic
paper. They have a rectangular cross-section with 32 mm inner width. A height of
approximately 10 mm is recommended.
The coils shall be fixed to an insulating and non-magnetic base in such a way as to form a
square (see figure 2). The length of the sides of the square formed by the internal edges of the
strips of the test specimen shall be 220ô mm (see figure 2).
Each of the four coils shall have two windings:
—
a primary winding, on the outside (magnetizing winding);
—
a secondary winding, on the inside (voltage winding).
NOTE - An electrostatic screen may be provided between these windings.
The windings shall be distributed uniformly over a minimum length of 190 mm, each coil having
one quarter of the total number of turns.
The individual primary windings of the four coils shall be connected in series, as shall be the
secondary windings. The number of primary and secondary turns may be adapted to the
particular conditions prevailing with regard to the power source, measuring equipment and
frequency.
NOTE - The total number of turns generally used and recommended is 700 or 1 000.
In order to reduce the effect of the impedances of the windings as much as possible, the
following requirements shall be met:
R1 R2
5_1,25 . 10 -6 E2 5 . 10-6 S2
N1
N2 2
L2
L1 <2,5•10 -9 H <5•10-9 H
N1 2 — N2 2
—
where
R1 and R2 are the resistances of the primary and secondary windings, respectively, in
ohms;
L 1 and L2 are the inductances of the primary and secondary windings, respectively, in
henrys;
N1 and N2
are the total number of turns of the primary and secondary windings,
respectively.
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SIST EN 60404-2:2002
404-2 © IEC:1996 – 13 –
NOTE – These requirements are satisfied, for example, if windings with the following characteristics are
used:
2 = 700;
– total number of turns: N. = 700, N
– primary (outer) winding: each of the four coils carries 175 turns of two copper wires connected in
parallel, each with a nominal cross-sectional area of approximately 1,8 mm 2
, wound side by side in three
layers;
– secondary winding: each of the four coils carries 175 turns of one copper wire with a nominal cross-
sectional area of 0,8 mm 2 wound in one layer.
The effective magnetic path length, lm, of the magnetic circuit shall be conventionally assumed
to be equal to 0,94 m. Therefore, the active mass, m a, that is the mass of the test specimen
which is magnetically active, is given by:
lm
ma =41 m (1)
where
l is the length of a test specimen strip, in metres;
lm is the conventional effective magnetic path length, in metres (1 m = 0,94 m);
the total mass of the test specimen, in kilograms;
m is
ma is the active mass of the test specimen, in kilograms.
3.4 Air flux compensation
The mutual inductor for air flux compensation shall be located in the centre of the space
enclosed by the four coils, its axis being directed normal to the plane of the axes of these coils.
The primary winding of the mutual inductor shall be connected in series with the primary
winding of the Epstein frame, and the secondary winding of the mutual inductor shall be
connected to the secondary winding of the Epstein frame in series opposition (see figure 3).
The adjustment of the value of the mutual inductance shall be made so that, when passing an
alternating current through the primary windings in the absence of the specimen in the
apparatus, the voltage measured between the non-common terminals of the secondary
windings shall be no more than 0,1 % of the voltage appearing across the secondary winding of
the test apparatus alone.
Thus the average value of the rectified voltage induced in the combined secondary windings is
proportional to the peak value of the magnetic polarization in the test specimen.
3.5 Power supply
The power supply shall have a low impedance and a high stability of voltage and frequency.
During measurements, the voltage and frequency variations shall not exceed ±0,2 % of the
required value.
For the determination of the specific total loss, the specific apparent power and the r.m.s. value
of the magnetic field strength, the form factor of the secondary voltage shall be 1,111 ± 1 %.
NOTE – This is possible in several ways: for example by using an electronically controlled power supply or a
negative feedback power amplifier. The form factor of the secondary voltage is the ratio of its r.m.s. value to
its average rectified value.
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SIST EN 60404-2:2002
404-2 © IEC:1996 – 15 –
Two voltmeters, one responsive to r.m.s. values and the other responsive to average rectified
values shall be used to determine the form factor.
NOTE — The waveform of the secondary induced voltage should be checked with an oscilloscope to ensure
that only the fundamental component is present.
3.6 Voltage measurement
The secondary voltage of the Epstein frame shall be measured by means of appropriate
voltmeters having an input impedance greater than or equal to 1 000 WV.
3.6.1 Average type voltmeter
A voltmeter responsive to average rectified values having an accuracy of ±0,2 % or better shall
be used.
NOTE — The preferred instrument is a digital voltmeter.
3.6.2 RMS voltmeter
A voltmeter responsive to r.m.s. values having an accuracy of ±0,2 % or better shall be used.
NOTE — The preferred instrument
...
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