SIST EN IEC 62822-3:2018

SLOVENSKI STANDARD
01-april-2018
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SIST EN 50505:2008
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Electric welding equipment - Assessment of restrictions related to human exposure to
electromagnetic fields (0 Hz to 300 Hz) - Part 3: Resistance welding equipment (IEC
62822-3:2017)
Matériels de soudage électrique - Évaluation des restrictions relatives à l'exposition
humaine aux champs électromagnétiques (0 Hz à 300 GHz) - Partie 3: Matériels de
soudage par résistance (IEC 62822-3:2017)
Ta slovenski standard je istoveten z: EN IEC 62822-3:2018
ICS:
13.280 Varstvo pred sevanjem Radiation protection
25.160.30 Varilna oprema Welding equipment
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN IEC 62822-3

NORME EUROPÉENNE
EUROPÄISCHE NORM
February 2018
ICS 25.160.30 Supersedes EN 50505:2008
English Version
Electric welding equipment - Assessment of restrictions related
to human exposure to electromagnetic fields (0 Hz to 300 Hz) -
Part 3: Resistance welding equipment
(IEC 62822-3:2017)
Matériels de soudage électrique - Évaluation des Einrichtungen zum Widerstandsschweißen - Bewertung
restrictions relatives à l'exposition humaine aux champs elektrischer Schweißeinrichtungen in Bezug auf
électromagnétiques (0 Hz à 300 GHz) - Partie 3: Matériels Begrenzungen der Exposition von Personen gegenüber
de soudage par résistance elektromagnetischen Feldern (0 Hz - 300 GHz) - Teil 3:
(IEC 62822-3:2017) Grundnorm für Widerstandsschweißeinrichtungen
(IEC 62822-3:2017)
This European Standard was approved by CENELEC on 2017-10-20. 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 62822-3:2018 E

European foreword
The text of document 26/626A/FDIS, future edition 1 of IEC 62822-3, prepared by IEC/TC 26 "Electric
welding" was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as
The following dates are fixed:
(dop) 2018-08-16
• latest date by which the document has to be
implemented at national level by
publication of an identical national
standard or by endorsement
• latest date by which the national (dow) 2021-02-16
standards conflicting with the
document have to be withdrawn
This document supersedes EN 50505:2008.

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 62822-3:2017 was approved by CENELEC as a European
Standard without any modification.

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 61786-1 -  Measurement of DC magnetic, AC EN 61786-1 -
magnetic and AC electric fields from 1 Hz
to 100 kHz with regard to exposure of
human beings - Part 1: Requirements for
measuring instruments
IEC 61786-2 -  Measurement of DC magnetic, AC - -
magnetic and AC electric fields from 1 Hz
to 100 kHz with regard to exposure of
human beings - Part 2: Basic standard for
measurements
IEC 62226-2-1 -  Exposure to electric or magnetic fields in EN 62226-2-1 -
the low and intermediate frequency range -
Methods for calculating the current density
and internal electric field induced in the
human body -- Part 2-1: Exposure to
magnetic fields - 2D models
IEC 62822-1 -  Electric welding equipment - Assessment EN 62822-1 -
of restrictions related to human exposure
to electromagnetic fields (0 Hz to 300 GHz)
- Part 1: Product family standard

IEC 62822-3 ®
Edition 1.0 2017-09
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Electric welding equipment – Assessment of restrictions related to human

exposure to electromagnetic fields (0 Hz to 300 GHz) –

Part 3: Resistance welding equipment

Matériels de soudage électrique – Évaluation des restrictions relatives à

l'exposition humaine aux champs électromagnétiques (0 Hz à 300 GHz) –

Partie 3: Matériels de soudage par résistance

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 25.160.30 ISBN 978-2-8322-4814-0

– 2 – IEC 62822-3:2017 © IEC 2017
CONTENTS
FOREWORD . 5
1 Scope . 7
2 Normative references . 7
3 Terms, definitions, quantities, units and constants . 8
3.1 Terms and definitions . 8
3.2 Quantities and units . 9
3.3 Constants . 10
4 Requirements . 10
5 Coupling coefficients . 10
5.1 General . 10
5.2 Conductive disks . 12
5.3 Anatomical body models for numerical calculations . 14
6 Source model . 14
6.1 General . 14
6.2 Single cable . 15
6.3 Parallel cables . 15
6.4 Rectangular loop . 16
7 Assessment methods . 18
7.1 General . 18
7.2 General considerations . 18
7.2.1 Time averaging . 18
7.2.2 Spatial averaging . 18
7.2.3 Frequency range limitations . 18
7.2.4 Measurement instruments . 19
7.2.5 Uncertainty of assessment . 19
7.3 Equipment with sinusoidal welding current . 19
7.4 Equipment with pulsed or non-sinusoidal welding current . 20
7.4.1 General . 20
7.4.2 Derivation of the weighting function from limits for field quantities . 20
7.4.3 Application of the weighted peak method in the frequency domain . 22
7.4.4 Application of the weighted peak method in the time domain . 23
7.5 Method based on measuring of external field levels . 23
7.5.1 General . 23
7.5.2 Measurement equipment . 23
7.5.3 Spatial averaging . 24
7.5.4 Exposure of the head . 24
7.5.5 Exposure of the trunk . 25
7.5.6 Exposure of the limbs . 25
7.6 Assessment procedure . 26
7.6.1 General . 26
7.6.2 Power-source . 27
7.6.3 Electrode-assembly . 27
7.6.4 Welding-system . 27
8 EMF data sheet and assessment report . 28
8.1 General . 28
8.2 EMF datasheet of components . 28

IEC 62822-3:2017 © IEC 2017 – 3 –
8.2.1 Power sources . 28
8.2.2 Electrode assemblies . 29
8.2.3 Other components . 29
Annex A (informative) Example of the weighted peak method in the time domain . 30
A.1 General . 30
A.2 Power source . 30
A.2.1 General . 30
A.2.2 Applied limits . 30
A.2.3 Assessment of the electrode-assembly . 32
A.2.4 Datasheets . 33
Annex B (informative) Example of the weighted peak method in the frequency domain . 37
B.1 General . 37
B.2 Power source . 37
B.2.1 General . 37
B.2.2 Applied limits . 38
B.2.3 Assessment of the electrode-assembly . 40
B.2.4 Datasheets . 41
Annex C (informative) IEC 62822-3 for users of IEC 62822-2 . 45
Annex D (informative) Coupling coefficients for common arrangements . 47
D.1 Single wire . 47
D.2 Example of standardized loop configurations . 48
D.2.1 0,5 m × 0,5 m . 48
D.2.2 1,0 m × 1,0 m . 50
D.2.3 1,0 m × 1,5 m . 52
Annex E (informative) Conservative approximation of coupling coefficients for
rectangular loops . 54
E.1 General . 54
E.2 XY-plane . 54
E.3 Z-direction . 55
E.4 Correlation factors . 56
Annex F (informative) Example EMF datasheets . 57
F.1 Example datasheet – Welding system . 57
F.2 Example datasheet − Power source . 59
F.3 Example datasheet – Electrode assembly . 60
Bibliography . 61

Figure 1 – Example of a reference system . 11
Figure 2 – Conducting disk in a uniform, time variant magnetic flux density . 12
Figure 3 – Electrical conductivity for homogeneous body models . 13
Figure 4 – Example of the placement of the conductive disks. 13
Figure 5 – Source model – Single cable . 15
Figure 6 – Assessment configuration – Single cable . 15
Figure 7 – Source model – Parallel cables . 15
Figure 8 – Assessment Configuration – Parallel Cables . 16
Figure 9 – Rectangular loop configuration . 16
Figure 10 – Assessment distances for the loop configuration . 17
Figure 11 – Piecewise linear and approximated limit amplitudes . 21

– 4 – IEC 62822-3:2017 © IEC 2017
Figure 12 – Piecewise linear and approximated summation function phase angles . 22
Figure 13 – Field measurement at head position . 24
Figure 14 – Field measurement at trunk position . 25
Figure 15 – Field measurement at limb positions, hand and thigh . 26
Figure 16 – Assessment of a complete welding system . 27
Figure 17 – Typical component based assessment . 27
Figure A.1 – Current waveform . 30
Figure A.2 – Combined ELVs for the head [1] . 31
Figure A.3 – Unity-coupling waveform . 31
Figure A.4 – Geometry of the electrode assembly . 32
Figure A.5 – Datasheet of the power source . 33
Figure A.6 – Datasheet of the electrode assembly . 34
Figure A.7 – Datasheet of the welding system . 35
Figure A.8 – Datasheet of the welding system . 36
Figure B.1 – Current waveform . 37
Figure B.2 – Spectrum of the current waveform . 38
Figure B.3 – Combined ELVs for the head [1] . 39
Figure B.4 – Unity-coupling waveform . 39
Figure B.5 – Geometry of the electrode assembly . 40
Figure B.6 – Datasheet of the power source . 41
Figure B.7 – Datasheet of the electrode assembly . 42
Figure B.8 – Datasheet of the welding system . 43
Figure B.9 – Datasheet of the welding system . 44
Figure E.1 – Geometry of the electrode assembly – XY-plane . 54
Figure E.2 – Geometry of the electrode assembly – Z-direction . 55
Figure F.1 – Example datasheet – Welding system . 57
Figure F.2 – Example datasheet – Power source . 59
Figure F.3 – Example datasheet – Power source . 60

Table 1 – Standardized distances . 11
Table 2 – Radii for the 2D disk model . 13
Table D.1 – Coupling coefficients – Single wire . 47
Table D.2 – Coupling coefficients XY-plane – Loop 0,5 m × 0,5 m . 48
Table D.3 – Coupling coefficients XY-plane – Loop 0,5 m × 0,5 m . 49
Table D.4 – Coupling coefficients XY-plane – Loop 1,0 m × 1,0 m . 50
Table D.5 – Coupling coefficients Z-plane – Loop 1,0 m × 1,0 m . 51
Table D.6 – Coupling coefficients XY-plane – Loop 1,0 m × 1,5 m . 52
Table D.7 – Coupling coefficients Z-plane – Loop 1,0 m × 1,5 m . 53
Table E.1 – Correlation factors – XY . 56
Table E.2 – Correlation factors − Z . 56

IEC 62822-3:2017 © IEC 2017 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ELECTRIC WELDING EQUIPMENT –
ASSESSMENT OF RESTRICTIONS RELATED TO HUMAN
EXPOSURE TO ELECTROMAGNETIC FIELDS (0 Hz TO 300 GHz) –

Part 3: Resistance welding equipment

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 62822-3 has been prepared by IEC technical committee 26:
Electric welding.
The text of this International Standard is based on the following documents:
FDIS Report on voting
26/626A/FDIS 26/630/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.

– 6 – IEC 62822-3:2017 © IEC 2017
A list of all parts in the IEC 62822 series, published under the general title Electric welding
equipment – Assessment of restrictions related to human exposure to electromagnetic fields
(0 Hz to 300 GHz), can be found on the IEC website.
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.
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.
IEC 62822-3:2017 © IEC 2017 – 7 –
ELECTRIC WELDING EQUIPMENT –
ASSESSMENT OF RESTRICTIONS RELATED TO HUMAN
EXPOSURE TO ELECTROMAGNETIC FIELDS (0 Hz TO 300 GHz) –

Part 3: Resistance welding equipment

1 Scope
This part of IEC 62822 applies to equipment for resistance welding and allied processes
designed for occupational use by professionals and for use by laymen.
NOTE 1 Typical allied processes are resistance hard and soft soldering or resistance heating achieved by means
comparable to resistance welding equipment.
This document specifies procedures for the assessment of human exposure to magnetic fields
produced by resistance welding equipment. It covers non-thermal biological effects in the
frequency range from 0 Hz to 10 MHz and defines standardized test scenarios.
NOTE 2 The general term "field" is used throughout this document for "magnetic field".
NOTE 3 For the assessment of exposure to electric fields and thermal effects, the methods specified in the
Generic Standard IEC 62311 or relevant basic standards apply.
This document does not define methods for workplace assessment regarding the risks arising
from electromagnetic fields (EMF). However, the EMF data that results from the application of
this Basic Standard can be used to assist in workplace assessment.
Other standards can apply to products covered by this document. In particular this document
cannot be used to demonstrate electromagnetic compatibility with other equipment. It does
not specify any product safety requirements other than those specifically related to human
exposure to electromagnetic fields.
This document focuses on the use of coupling coefficients to assess the exposure to EMF.
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 61786-1, Measurement of DC magnetic, AC magnetic and AC electric fields from 1 Hz to
100 kHz with regard to exposure of human beings – Part 1: Requirements for measuring
instruments
IEC 61786-2, Measurement of DC magnetic, AC magnetic and AC electric fields from 1 Hz to
100 kHz with regard to exposure of human beings – Part 2: Basic standard for measurements
IEC 62226-2-1, Exposure to electric or magnetic fields in the low and intermediate frequency
range – Methods for calculating the current density and internal electric field induced in the
human body – Part 2-1: Exposure to magnetic fields – 2D models
IEC 62822-1, Electric welding equipment – Assessment of restrictions related to human
exposure to electromagnetic fields (0 Hz to 300 GHz) – Part 1: Product family standard

– 8 – IEC 62822-3:2017 © IEC 2017
3 Terms, definitions, quantities, units and constants
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60050-851,
IEC 60974-1, IEC 60974-6, and the following 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
3.1.1
basic restrictions
exposure limit value
restrictions on exposure to electric, magnetic and electromagnetic fields that are based
directly on established health effects and biological considerations
3.1.2
coupling coefficient
CC , CC , CC
B J E
coupling-coefficient that map the electric current in a field source to the maximum of the
external magnetic flux density (CC ), the maximum intracorporeal induced electric current
B
density (CC ) or the maximum intracorporeal electric field strength (CC ) respectively
J E
Note 1 to entry: Keeping in mind that the electric conductivity can be frequency dependent, a conversion between
CC and CC is possible with the relation given in Formula (1)
J E
J( jω) = σ( jω) ⋅ E( jω) (1)
3.1.3
exposure index
EI
result of the evaluation of exposure to (both sinusoidal and non-sinusoidal) EMF, expressed
as a fraction or percentage of the permissible values
Note 1 to entry: Fractions higher than 1 (100 %) exceed the permissible values.
3.1.4
general public
individuals of all ages and of varying health conditions
3.1.5
health effect
adverse effect, such as thermal heating or stimulation of nerve and muscle tissue as a result
of human exposure to EMF
3.1.6
intracorporeal
situated or occurring within the body
3.1.7
layman
operator who does not weld in the performance of his profession and may have little or no
formal instruction in welding
[SOURCE: IEC 60050-851, 851-11-14, modified – "Arc welding" was replaced by "welding".]

IEC 62822-3:2017 © IEC 2017 – 9 –
3.1.8
non-thermal effect
stimulation of muscles, nerves or sensory organs as a result of human exposure to EMF
3.1.9
occupational exposure
exposure of workers to EMF at their workplaces, generally under known conditions, and as a
result of performing their regular or assigned job activities
Note 1 to entry: A worker is any person employed by an employer, including trainees and apprentices
3.1.10
reference level
directly measurable quantity, derived from basic restrictions, provided for practical exposure
assessment purposes
Note 1 to entry: Respect of the reference levels will ensure respect of the relevant basic restriction. If the
reference levels are exceeded, it does not necessarily follow that the basic restriction will be exceeded.
3.1.11
resistance welding system
combination of power source, transformer, cabling and welding circuit
3.1.12
sensory effect
transient disturbed sensory perceptions and minor change in brain functions as a result of
human exposure to EMF
3.1.13
standardized configuration
configuration reflecting the normal operator positions
3.1.14
standardized distance
distance from the axis of a part of the welding circuit to the closest surface of the body in
standardized configurations
3.1.15
welding circuit
conductive material through which the welding current is intended to flow
Note 1 to entry: In resistance welding, the workpieces are not part of the welding circuit for the purposes of this
document.
[SOURCE: IEC 60050-851, 851-14-10, modified – The two notes to entry have been deleted,
and a new note to entry has been added.]
3.2 Quantities and units
The internationally accepted SI units are used throughout this document.
Symbols set in bold type are vector quantities.

– 10 – IEC 62822-3:2017 © IEC 2017
Physical quantity Symbol Unit Dimension
-1
Electric conductivity Siemens per metre S m
σ
Electric current I Ampere A
-2
Electric current density J Ampere per square metre A m
-1
Electric field strength E Volt per metre V m
ƒ
Frequency Hertz Hz
-2
Magnetic flux density B Tesla V s m
-1
Magnetic permeability Henry per metre H m
µ
3.3 Constants
Physical constant Symbol Magnitude Dimension
-1
-7
Permeability of free space H m
µ 4⋅π ⋅10
4 Requirements
Equipment shall be assessed as defined in Clause 8.
Assessments shall follow the provision in Clause 7.
If the assessment is conducted using calculated external field levels, 7.5 shall be applied in
conjunction with Clause 5.
The results shall be reported as specified in Clause 8.
5 Coupling coefficients
5.1 General
A reference system shall be defined to measure the distances between the field source and
the part of the human body to be assessed.
For occupational exposure, Figure 1 shows an example where two directions of approach are
sufficient to be taken into account for setting a reference system.

IEC 62822-3:2017 © IEC 2017 – 11 –
CCmax CCmax
d d
2 1
CCmax
d
CCmax
d
d
1 d
d
d 2
IEC
IEC
Side view Front view
Figure 1 – Example of a reference system
NOTE 1 For other systems, other directions of approach can be considered because of its usage. More examples
are shown in Annex A and Annex B.
NOTE 2 In Figure 1, the actual position of the highest CC in respect to the separation distance is only given for
further illustration purposes.
NOTE 3 The front-view in Figure 1 illustrates a situation where the position of the highest CC changes in respect
to the separation distance and symmetry-axis of the loop.
The coupling coefficients shall map a given welding current to the highest field quantity found
at a specific separation distance within this reference system keeping in mind the degrees of
freedom provided by the reference system.
NOTE 4 Annex C contains theoretical background information.
Separation distances are given in Table 1 and represent the standardized configurations.
If applicable national and international requirements exclude specific configurations (e.g. the
assessment of the exposure of limbs is not required), coupling coefficients for these
configurations may be omitted.
If applicable national and international requirements specifically call for the application of
exposure configurations covered by this document, suitable assessment configurations
following the underlying principles in Clauses 5, 6 and 7 shall be derived.
NOTE 5 For different field quantities (B, J, E) different sets of coupling factors can be used.
Clause 6 shall be applied for the modelling of the field source when deriving coupling
coefficients for different field quantities.
Table 1 – Standardized distances
Head 300 mm
Trunk
200 mm
Limbs 100 mm
– 12 – IEC 62822-3:2017 © IEC 2017
The coupling coefficients CC , and CC shall be obtained by the methods given in 5.2 and 5.3
J E
as found appropriate by the manufacturer.
CC shall be either obtained using calculated (Clause 6) or measured (7.5) values of the
B
magnetic flux density B.
The coupling coefficients CC for the different field quantities shall be calculated with Formulas
(2), (3) and (4).
B
max
CC (R,d) = (2)
B
I
J ( f )
max
CC (R,d) = (3)
J
I ⋅ f
E ( f )
max
CC (R,d) = (4)
E
I ⋅ f
where
I is the welding current;
f is the frequency of the welding current;
R is the disk radius;
d is the distance to the field source;
B , J , E are the maxima of the field quantities B, J and E respectively.
max max max
5.2 Conductive disks
The simplest analytical model used in EMF health guidelines is based on the hypothesis of
coupling between a uniform, external magnetic field at a single frequency, and a
homogeneous disk of given conductivity, used to represent the part of the body under
consideration. This is illustrated in Figure 2.
z
B (t)
y
i (t)
x
IEC
Figure 2 – Conducting disk in a uniform,
time variant magnetic flux density
The radii of the disks which shall be used for calculations with regard to head, trunk and limbs
of the welder's body are given in Table 2.

IEC 62822-3:2017 © IEC 2017 – 13 –
Table 2 – Radii for the 2D disk model
Limbs
Head Trunk
Hand Thigh
Disk radius R 100 mm 200 mm 50 mm 100 mm

The electrical parameters used for modelling the human body are very critical. Average values
of the electrical conductivity σ are given in Figure 3. These average values shall only be used
for assessment procedures using simplified body models with homogeneous electrical
conductivity.
0,6
0,5
0,4
0,3
0,2
0,1
0,001 0,01 0,1 1 10 100 1 000 10 000
Frequency, kHz
IEC
Figure 3 – Electrical conductivity for homogeneous body models
NOTE The frequency range can be limited when determining the coupling coefficients as appropriate.
The uncertainty for these values shall be taken as 0 % since the average values of the
electrical conductivity, combined with the application of homogeneous body models, provide a
conservative approach to the assessment of exposure.
IEC 62226-2-1 describes in detail the procedure to find E and J within the disk area.
max max
To minimize numerical errors, appropriate averaging methods shall be applied to the induced
field quantities.
z
y
x
IEC
Figure 4 – Example of the placement of
the conductive disks
–1
Conductivity, S m
– 14 – IEC 62822-3:2017 © IEC 2017
Due to the nature of the magnetic field, the disk position giving the highest exposure changes
with respect to the distance to the field source. In Figure 4, the solid disks represent the
locations giving the highest exposure with respect to the assessment distance.
5.3 Anatomical body models for numerical calculations
Induced current density or intracorporeal electric field-strength may be derived by numerical
simulation using a 3D body model where the dielectric properties of the various tissues are
taken into account.
The body model shall represent relevant parts of the body (i.e. head, trunk or limbs) or the
whole body, as applicable based on the relevant applicable national and international
requirements setting limits.
If such simulation techniques are used, appropriate validation is required. This can be
provided by peer review, appropriate published reference citations or comparison against
other reviewed or referenced models.
Considerations on the methodology for numerical simulations is given in IEC 62226-2-1.
th
The 99 percentile value of the vectorial averages of the induced field quantities within small

contiguous tissue volumes of 2 mm × 2 mm × 2 mm shall be used for the assessment. This is
restricted to skin tissue.
6 Source model
6.1 General
The main source of EMF is the welding current flowing through the welding circuit, generating
a low frequency magnetic field. This has the greatest contributor to the exposure index EI.
The magnetic field produced by the welding current is non-homogeneous in close proximity to
the equipment.
The parameters of the welding current (e.g. amplitude and waveform), and the welding circuit
characteristics (e.g. dimensions), are determined by the equipment only. External factors, for
example characteristics of the work piece, may have influence on the magnetic field, but are
not taken into account by this document.
NOTE 1 This assumption allows the use of filamentary currents and renders the application of Biot-Savart’s Law
possible.
Therefore, assessment shall be based on these parameters and the configuration of the
welding circuit as specified in this document.
The fact that a magnetic field in the space surrounding resistance welding equipment is non-
homogeneous shall be taken into account.
Configuration with simple solutions for the magnetic flux density are given in 6.2, 6.3 and 6.4.
IEC 62226-2-1 gives more information on how to assess more complex situations.
Other methods (e.g. numerical methods) may be used as long as they provide equivalent
results.
NOTE 2 An example is the evaluation of the full set of Maxwell’s equations.

IEC 62822-3:2017 © IEC 2017 – 15 –
6.2 Single cable
For a single cable a source model as given in Figure 5 shall be used.
y
𝑒𝑒⃗φ
𝑟𝑟⃗ P
x
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Figure 5 – Source model – Single cable
Due to the symmetry of the field distribution, only a single distance d to the centre of the
conductor as shown in Figure 6 shall be considered when deriving the coupling coefficients.
The magnitude of the magnetic flux density B is given in Formula (5).
I
d
x
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Figure 6 – Assessment configuration – Single cable
µ
B(d) = ⋅ I (5)
2 π d
where
d is the distance to the field source.
6.3 Parallel cables
For two parallel cables a source model as given in Figure 7 shall be used.
z
P
r r
1 2
y
s/2 s/2
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Figure 7 – Source model – Parallel cables
Since the field distribution does not change along the x-axis, two distances (d , d ) as shown
y z
in Figur
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