IEC 62822-3:2023

Electric welding equipment - Assessment of restrictions related to human exposure to electromagnetic fields (0 Hz to 300 GHz) - Part 3: Resistance welding equipment

IEC 62822-3:2023 applies to equipment for resistance welding and allied processes designed for occupational use by professionals and for use by laymen.
More generally, this document covers equipment for which the welding current flows in an electrical circuit whose geometry cannot be changed and regardless of the technology of the current generator (for example LF-AC, MF-DC for spot or seam welding or capacitive discharge used for stud welding).
This second edition cancels and replaces the first edition published in 2017. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous edition:
a) inclusion of the uncertainties in the results of the assessment;
b) simplification of the methods of exposure assessment.

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

L'IEC 62822-3:2023 s'applique aux matériels de soudage par résistance et techniques connexes conçus pour un usage professionnel et non professionnel.
Plus généralement, le présent document traite des matériels où le courant de soudage circule dans un circuit électrique dont la géométrie ne peut pas être modifiée, quelle que soit la technologie du générateur de courant (par exemple LF-AC, MF-DC pour le soudage par points ou continu, ou le soudage par décharge capacitive utilisé pour le soudage de goujons).
Cette deuxième édition annule et remplace la première édition parue en 2017. Cette édition constitue une révision technique.
Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
a) inclusion des incertitudes dans les résultats de l'évaluation;
b) simplification des méthodes d'évaluation de l'exposition.

General Information

• Status: Published
• Publication Date: 30-May-2023
• ICS: 25.160.30 - Welding equipment
• Technical Committee: TC 26 - Electric welding
• Drafting Committee: WG 5 - TC 26/WG 5
• Current Stage: PPUB - Publication issued
• Start Date: 23-Jun-2023
• Completion Date: 31-May-2023

Relations

• Revises: IEC 62822-3:2017 - Electric welding equipment - Assessment of restrictions related to human exposure to electromagnetic fields (0 Hz to 300 Hz) - Part 3: Resistance welding equipment
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC 62822-3 ®
Edition 2.0 2023-05
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
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IEC 62822-3 ®
Edition 2.0 2023-05
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 978-2-8322-7056-1

– 2 – IEC 62822-3:2023 © IEC 2023
CONTENTS
FOREWORD . 6
1 Scope . 8
2 Normative references . 8
3 Terms, definitions, quantities, units, constants and symbols . 9
3.1 Terms and definitions . 9
3.2 Quantities and units . 11
3.3 Constants . 11
3.4 Symbols . 12
4 Requirements . 12
5 Assessment methods . 13
5.1 General . 13
5.2 Methods based on reference levels . 13
5.2.1 General . 13
5.2.2 Assessment based on measured magnetic field . 14
5.2.3 Assessment based on measured welding current . 16
5.3 Methods based on assessment of corporal quantities (basic restrictions) . 18
5.3.1 General . 18
5.3.2 Method based on coupling coefficients . 19
5.3.3 Method based on the correction factor . 21
5.3.4 Method based on the human model simulation. 22
5.3.5 Result comparison . 24
6 Measurement considerations . 24
6.1 Measurement instruments for magnetic fields or exposure levels . 24
6.1.1 General . 24
6.1.2 Probe(s) . 25
6.1.3 Handheld field meter . 25
6.1.4 Measurement system with separate elements . 25
6.2 Instruments for recording . 26
6.2.1 Welding current recording . 26
6.2.2 Magnetic field recording. 26
6.3 Signal processing (applicable to any welding current waveform) . 27
6.3.1 General . 27
6.3.2 Application of the weighted peak method in the time domain . 27
6.3.3 Spatial averaging . 27
6.3.4 Time averaging . 27
6.4 Uncertainty of assessment . 27
7 Computational assessment methods . 28
7.1 General . 28
7.2 Quasi-static approximation . 28
7.3 Human body models for simulation . 28
7.4 Computational assessment against the basic restrictions . 29
8 Source model . 30
8.1 General . 30
8.2 Source model example . 30
9 EMF data sheet and assessment report . 32
Annex A (informative) Example of assessment based on the individual components . 34

A.1 General . 34
A.2 Welding current generator . 34
A.3 Coupling coefficient of welding circuit . 37
A.4 Welding-system . 38
Annex B (informative) Example datasheets . 40
B.1 Example current generator datasheet. 40
B.2 Example datasheet of the welding circuit . 41
B.3 Example datasheets of equipment assembly . 42
Annex C (informative) Coupling coefficient method . 45
C.1 Principle . 45
C.2 Validation of this method . 45
C.2.1 Context . 45
C.2.2 Basic restriction against health effects . 46
C.2.3 Basic restriction against sensory effects . 46
C.3 Conclusion . 47
Annex D (informative) Correction factor method . 49
D.1 General . 49
D.2 Principle . 49
D.3 Example of correction factor finding . 50
D.3.1 Context . 50
D.3.2 Correction factor for the trunk and limbs . 50
D.3.3 Correction factor for the head . 50
D.4 Conclusion . 51
Annex E (informative) Example of exposure assessments on a welding machine . 52
E.1 General . 52
E.2 Description of the spot welding workstation . 52
E.3 Exposure conditions . 52
E.4 Main simulation parameters and results . 54
E.4.1 Main simulation parameters . 54
E.4.2 Simulation results . 55
E.5 Exposure assessments . 55
E.5.1 General . 55
E.5.2 Method based on magnetic field calculation . 55
E.5.3 Method based on coupling coefficients . 55
E.5.4 Method based on the correction factor . 56
E.5.5 Method based on the human model . 56
E.6 Conclusion . 57
Annex F (informative) Computational methods . 58
F.1 General . 58
F.2 SPFD method . 58
F.3 Quasi-static – Finite element method . 58
F.4 Impedance method . 59
F.5 Hybrid technique of FEM and SPFD method . 60
F.6 Computation of the magnetic vector potential . 60
Annex G (informative) Averaging algorithms . 62
G.1 Current density averaging over an area . 62
G.1.1 General . 62
G.1.2 Calculation of the current density in a Cartesian voxel . 62

– 4 – IEC 62822-3:2023 © IEC 2023
G.1.3 Calculation of the current density in a tetrahedron . 63
G.1.4 Calculation of J . 63
avg
G.2 E-field averaging in a cubical volume . 64
G.3 E-field averaging along an averaging distance . 64
G.3.1 General . 64
G.3.2 Algorithm to construct the integration path . 65
Annex H (informative) Correspondence table between time domain and frequency
domain . 66
Bibliography . 68

Figure 1 – Exposure measurement at the head position . 15
Figure 2 – Exposure measurement at trunk position . 15
Figure 3 – Exposure measurement at limb positions (hands and thigh) . 16
Figure 4 – Compliance perimeters according to reference levels (action levels) . 18
Figure 5 – Compliance perimeters according to basic restrictions (exposure limit

values) . 21
Figure 6 – Magnetic field around the human body obtained by source modelling . 23
Figure 7 – Example of induced electric field in a human body exposed to a welding gun
(I = 1kA to 50 Hz) . 24
Figure 8 – Welding current flowing in a (a × b) rectangular loop configuration . 31
Figure A.1 – Assessment of a complete welding system . 34
Figure A.2 – Typical component based assessment . 34
Figure A.3 – LF-AC (left) and MF-DC (right) current waveforms . 35
Figure A.4 – Combined ELV for the sensory and health effects applicable to the head . 35
Figure A.5 – Current exposure indices over the time for two welding technologies . 36
Figure A.6 – Geometry of the stationary spot welding gun . 37
Figure A.7 – Welding electric circuit model (in m) and one point of interest along the
X axis . 37
Figure A.8 – Coupling coefficient CC along the X axis . 38
BI
Figure A.9 – Exposure index (AL) along the X axis . 38
Figure A.10 – Exposure index (ELV) along the X axis . 39
Figure B.1 – Example datasheet of the power source . 40
Figure B.2 – Example datasheet of the electrode assembly . 41
Figure B.3 – Datasheet example of the welding system . 42
Figure B.4 – Example datasheet of the welding system (continuation) . 43
Figure B.5 – Example datasheet of the welding system (continuation) . 44
Figure C.1 – Distribution of human to disk model exposure index ratios (health effects

of ELV on trunk and hands) . 46
Figure C.2 – Distribution of human to disk model exposure index ratios (sensory and
health effects of ELV on the head) . 47
Figure D.1 – Distribution of correction factor k for health effects on trunk and hands . 50
E
Figure D.2 – Distribution of correction factor k for effects on the head (sensory and
E
health) . 51
Figure E.1 – Welding gun and its electric circuit model (yellow dash segments) . 53
Figure E.2 – Magnetic field distribution around the exposed body . 53

Figure E.3 – Configuration and electric field distribution on the exposed body
(for 1 kA at f = 50 Hz) . 54
Figure E.4 – Electric field distribution on hands (for 1 kA at f = 50 Hz) . 54
Figure G.1 – Field components on voxel edges . 63

Table 1 – Examples of human models to determine induced electric fields in the low
frequency range . 29
Table A.1 – Current exposure index for LF-AC technology (I = 11,4 kA) . 36
rms
Table A.2 – GP current exposure index for LF-AC technology (I = 11,4 kA) . 36
rms
Table C.1 – Representative disk radius (geometric model) . 45
Table C.2 – Coupling coefficients . 47
Table E.1 – Coupling coefficients for the magnetic field and on human model . 55
Table E.2 – Results based on magnetic field calculation . 55
Table E.3 – Results based on coupling coefficients . 56
Table E.4 – Results based on the correction factor . 56
Table E.5 – Results based on human model . 56
Table H.1 – Transcription of formulae . 66

– 6 – IEC 62822-3:2023 © IEC 2023
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
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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.
IEC 62822-3 has been prepared by IEC technical committee 26: Electric welding. It is an
International Standard.
This second edition cancels and replaces the first edition published in 2017. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) inclusion of the uncertainties in the results of the assessment;
b) simplification of the methods of exposure assessment.

The text of this International Standard is based on the following documents:
Draft Report on voting
26/744/FDIS 26/745/RVD
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/publications.
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 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 document 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.

– 8 – IEC 62822-3:2023 © IEC 2023
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.
More generally, this document covers equipment for which the welding current flows in an
electrical circuit whose geometry cannot be changed and regardless of the technology of the
current generator (for example LF-AC, MF-DC for spot or seam welding or capacitive discharge
used for stud welding).
NOTE 1 Allied processes such as resistance hard and soft soldering or resistance heating achieved by means
comparable to resistance welding equipment are included as well.
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 IEC 62311
or relevant basic standards will apply.
This document aims to propose methods for providing EMF exposure data that can be used to
assist in the assessment of the workplace, especially when the conditions of use of the
equipment are not known. When these are technically constrained (for example, a double hand
control imposes the position and posture of the user), the data can be directly exploitable if they
fall within the scope specified by the manufacturer or the integrator.
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 proposes several methods to assess the exposure to EMF, from simple to
sophisticated, with the latter providing more precise assessment.
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 60050-851:2008, International Electrotechnical Vocabulary (IEV) – Part 851: Electric
welding (available at www.electropedia.org)
IEC 60974-1, Arc welding equipment – Part 1: Welding power sources

IEC 60974-6, Arc welding equipment – Part 6: Limited duty equipment
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 61786-2:2014, 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 62311, Assessment of electronic and electrical equipment related to human exposure
restrictions for electromagnetic fields (0 Hz to 300 GHz)
IEC 62822-1:2016, Electric welding equipment – Assessment of restrictions related to human
exposure to electromagnetic fields (0 Hz to 300 GHz) – Part 1: Product family standard
3 Terms, definitions, quantities, units, constants and symbols
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 terminology databases for use in standardization at the following
addresses:
• IEC Electropedia: available at https://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp
3.1.1
basic restriction
restriction on exposure to electric, magnetic and electromagnetic fields that is based directly on
established health effects and biological considerations
Note 1 to entry: Basic restrictions are also named dosimetric reference limits (DRLs) and exposure limit values
(ELVs).
3.1.2
coupling-coefficient
CC
YX
relation allowing to estimate Y from X
EXAMPLE CC gives the maximum induced electric field inside a region of the human body according a unit welding
EI
current.
Note 1 to entry: Keeping in mind that the electric conductivity can be frequency dependent, a conversion between
CC and CC or CC and CC is possible with the relation given in Formula (1)
JI EI JB EB
J jω σ jω⋅ E jω
( ) ( ) ( ) (1)
=
– 10 – IEC 62822-3:2023 © IEC 2023
where
J is the electric current density, expressed in ampere per square meter;
E is the electric field strength, expressed in volt per meter;
σ is the conductivity, expressed in siemens per meter;
ω is the angular frequency (2·π · f), expressed in radians per second”.
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
intracorporeal
situated or occurring within the body
3.1.6
layman
operator who does not weld in the performance of his profession and may have little or no
formal instruction in welding
[SOURCE: IEC 60050-851:2008, 851-11-14, modified – “arc welding” was replaced with
“welding”.]
3.1.7
non-thermal effect
stimulation of muscles, nerves or sensory organs as a result of human exposure to EMF
3.1.8
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.
3.1.9
reference level
directly measurable quantity, derived from basic restrictions, provided for practical exposure
assessment purposes
Note 1 to entry: Reference levels are also named exposure reference levels (ERLs) and action levels (Als).
Note 2 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.
3.1.10
resistance welding system
combination of power source, transformer, cabling and welding circuit
3.1.11
sensory effect
transient disturbed sensory perceptions and minor change in brain functions as a result of
human exposure to EMF
3.1.12
standardized configuration
configuration reflecting the normal operator positions
3.1.13
standardized distance
distance from the axis of a part of the welding circuit to the closest surface of the body in
standardized configurations
3.1.14
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 60050-851:2008, 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 throughout this document set in bold type are vector quantities.
Physical quantity Symbol Unit Dimension
. -1
σ
Electric conductivity Siemens per metre S m
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
Frequency ƒ Hertz Hz
. 2
B
Magnetic flux density Tesla T (V s/m )
. -1
µ
Magnetic permeability Henry per metre H m
Wavelength λ Metre m
3.3 Constants
Physical constant Symbol Magnitude Dimension
-7 . -1
Permeability of free space µ
4 · π · 10 H m
– 12 – IEC 62822-3:2023 © IEC 2023
3.4 Symbols
Symbols used in this document are expanded hereafter.
Symbols Meaning
* Convolution product i.e. B(t)*WL(t) means filtering B(t) by WL(t)
t Time
f Frequency of a single frequency signal
B(t) Magnetic flux density (magnetic field) in the time domain
B(f) Magnetic flux density (magnetic field) in the frequency domain
B (f)
B reference level at f
RL
W (t)
Time (impulse) response of the weighted filter according to the reference level
RL
W (f)
Frequency response of the weighted function according to the reference level
RL
EI
Exposure index according to the reference level
RL
I(t) / I Welding current in the time domain/frequency domain
CC
Coupling coefficient from I to B (frequency independent)
BI
−1
Inverse Fourier transform

dB/dt Time derivate of the magnetic flux density
R Disk radius of 2D geometric model
E
Induced or internal electric field
i
dI/dt Time derivate of the welding current
W (t)
Time (impulse) response of the weighted filter according to the basic restriction
BR
W (f)
Frequency response of the weighted function according to the basic restriction
BR
CC Coupling coefficient from B to E with geometric model
EB/2D i
CC Coupling coefficient from I to E with human model
EI/HM i
EI
Exposure index according to the exposure limit value (basic restriction)
BR
k
Exposure index coefficient
E
CEI
Current exposure index according to the basic restrictions
BR
4 Requirements
Equipment shall be assessed as defined in Clause 5.
If the assessment is conducted using measured or calculated external field levels, 5.2 shall be
applied in conjunction with Clause 6.
If the assessment is conducted using corporal quantities, 5.3 shall be applied in conjunction
with Clause 6 if measurements are performed and in conjunction of Clause 7 if a human model
is applied.
The results shall be reported as specified in Clause 9.

5 Assessment methods
5.1 General
Clause 5 provides basic assessment methods considering the direct effects of electromagnetic
fields [2], [3], [4], [5], [6], [7], [8] . Evaluations are made either against basic restrictions or
against derived reference levels. In international guidelines, different limits on basic restrictions
and reference levels are defined for stimulation effects which are considered for exposure to
low frequency magnetic fields.
There are five methods to assess the welding equipment exposure and to demonstrate
conformity or give enough information to demonstrate it with the reference levels or basic
restrictions, or both. Any of the five methods can be selected, depending on which is the most
relevant for the exposure assessment. If one of the first four methods does not lead to
compliance, another can be chosen. The ultimate method is the fifth (dosimetry with human
model).
While the evaluation based on measuring incident magnetic fields against reference levels is
the easiest method (see 5.2.2), the evaluation based on computed magnetic field from the
welding current can predict the exposure, and it does not require a field meter (see 5.2.3).
Those methods are necessarily more conservative than the assessment of exposure according
to induced quantities against basic restrictions.
Thus, the evaluation of internal (or induced) E-field or current density against basic restrictions
(5.3) is performed with more realistic exposure conditions considering mainly the heterogeneity
of the magnetic field.
Evaluations of induced fields against basic restrictions using simple (geometric) models are
methods of intermediate complexity (see 5.3.2 and 5.3.3). As these methods have to cover a
large number of situations, they are conservative most of the time and in extreme cases, they
become accurate.
Lastly, evaluation of induced fields against basic restrictions with an electrical representative
human body is the most rigorous and reduces uncertainties. It requires simulation after a faithful
modelling of the environment (see 5.3.4).
5.2 Methods based on reference levels
5.2.1 General
The assessments are based on external (incident) magnetic fields against reference levels.
Reference levels have been derived from the basic restrictions considering the conditions which
maximized the exposure (whole body exposure to a uniform field). Such an assessment is
conservative under all non-uniform and local exposure conditions, which is the case in most
occupational exposure situations. Therefore, this method is simple but it overestimates
exposure to welding equipment most of the time.
The exposure level is determined by a comparison of the magnetic field and the relevant
exposure limits applicable to the affected regions of the body.
___________
Numbers in square brackets refer to the Bibliography.

– 14 – IEC 62822-3:2023 © IEC 2023
5.2.2 Assessment based on measured magnetic field
5.2.2.1 General
The method based on the measured magnetic field is convenient when the use of equipment is
known. In general, the assessment is performed on one or two welder positions.
Exposure shall be performed on the trunk, near the head, on both hands and on the thighs when
they are the closest part to the welding electric circuit. This leads to four, sometimes five,
measurement points on each welder position as described in 5.2.2.2 to 5.2.2.4. The measuring
points are the places where the measured level is the maximum (worst-case point) of the
different parts of the body. In general, they are closest to the welding circuit. A scan on the
surface of each body part can help determine these positions.
The reading values at these points should be recorded together with the positions in the
compliance testing report in order to carry out reproduceable measurements.
In practice, a magnetic field meter is able to measure either the magnetic field (in tesla) or the
exposure index directly according to the relevant exposure limit. Most often the meter
...