IEC 61000-4-23:2016

IEC 61000-4-23 ®
Edition 2.0 2016-10
INTERNATIONAL
STANDARD
colour
inside
BASIC EMC PUBLICATION
Electromagnetic compatibility (EMC) –
Part 4-23: Testing and measurement techniques – Test methods for protective
devices for HEMP and other radiated disturbances

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IEC 61000-4-23 ®
Edition 2.0 2016-10
INTERNATIONAL
STANDARD
colour
inside
BASIC EMC PUBLICATION
Electromagnetic compatibility (EMC) –

Part 4-23: Testing and measurement techniques – Test methods for protective

devices for HEMP and other radiated disturbances

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 33.100.99 ISBN 978-2-8322-3687-1

– 2 – IEC 61000-4-23:2016 © IEC 2016
CONTENTS
FOREWORD . 6
INTRODUCTION . 8
1 Scope . 9
2 Normative references . 9
3 Terms and definitions . 10
4 HEMP test concepts . 15
4.1 General . 15
4.2 Testing of shielding enclosures . 16
4.2.1 General . 16
4.2.2 Buildings . 19
4.2.3 Shelters and shielded rooms . 20
4.2.4 Cabinets, racks and boxes . 21
4.3 Testing of shielded cables and connectors . 23
4.3.1 General . 23
4.3.2 Testing of cable shields . 23
4.3.3 Testing of cable connectors . 26
4.4 Testing of shielding materials . 27
4.4.1 General . 27
4.4.2 Conducting gaskets . 27
4.4.3 Conducting sheets and screens . 29
4.4.4 Cut-off waveguides and honeycombs . 32
4.5 Summary of test concepts . 33
5 Test methods for measuring the shielding effectiveness of HEMP protection
facilities . 34
5.1 General . 34
5.2 Electromagnetic field testing . 34
5.2.1 General . 34
5.2.2 Pulse field testing . 34
5.2.3 CW field testing . 40
5.3 Current injection test procedures . 55
5.3.1 General . 55
5.3.2 Injection testing of enclosures . 55
5.3.3 Transfer impedance and admittance of cable shields and connectors . 57
5.3.4 Testing of gasket material . 57
Annex A (informative) HEMP test concepts for electrical systems . 60
A.1 Overview. 60
A.2 Types of HEMP tests . 60
A.2.1 General . 60
A.2.2 System-level transient tests . 60
A.2.3 CW field illumination tests . 61
A.2.4 Current injection testing . 61
A.2.5 Partial illumination testing . 62
A.2.6 Subsystem and component testing . 62
A.3 Definition of the testing interface . 63
A.4 Use of test data . 65
A.4.1 General . 65

A.4.2 Acceptance of new systems . 65
A.4.3 System assessments . 65
A.4.4 Hardness surveillance monitoring . 65
A.4.5 System design . 65
A.5 Testing uncertainties . 66
Annex B (informative) Characterization of shielded cables . 67
B.1 Fundamentals of cable shielding . 67
B.2 Definitions of transfer impedance and transfer admittance . 68
B.3 Relative significance of Z′ and Y′ . 71
t t
Annex C (informative) Equipment for HEMP pulse measurements . 72
C.1 General . 72
C.2 Sensors for HEMP measurements . 72
C.2.1 B- and H-field sensors . 72
C.2.2 D- and E-field sensors . 74
C.2.3 Current sensors . 76
C.3 Signal transmission . 77
C.3.1 General . 77
C.3.2 Fibre optic links . 77
C.3.3 Fibre optic transducers . 78
C.4 Signal detection and processing . 78
Annex D (informative) Equipment for CW testing . 80
D.1 General . 80
D.2 Antenna system . 80
D.3 Power amplifier . 82
D.4 Receiver (network analyser). 83
D.5 Reference and response sensors . 83
D.6 Fibre optic system . 85
D.7 Limitations of measurements . 88
Annex E (informative) Characterization of a planar shield for HEMP protection . 89
E.1 General . 89
E.2 Problem geometry . 90
E.3 Equivalent circuit representation . 91
E.3.1 General . 91
E.3.2 Chain parameter representation of the shield . 92
E.3.3 Circuit responses . 93
Annex F (informative) Inside-to-out measurement method . 97
F.1 Purpose . 97
F.2 Comparison of existing SE test methods . 97
F.3 Inside-to-out SE test of shielded rooms . 98
F.3.1 Measurements of the inside-to-out SE . 98
F.3.2 Summary . 101
Bibliography . 102

Figure 1 – Example of measured magnitude and phase of the transfer function
T(ω) = H /H for a shielded enclosure . 17
in out
Figure 2 – Electric field and magnetic field shielding effectiveness of a 0,5 mm thick
aluminum enclosure [29] . 18
Figure 3 – Measured magnetic field shielding effectiveness SE for a building . 19
H
– 4 – IEC 61000-4-23:2016 © IEC 2016
Figure 4 – Conceptual illustration of the HEMP test of a building . 19
Figure 5 – Illustration of a shielded room or enclosure excited by HEMP fields . 21
Figure 6 – Illustration of equipment racks, cabinets and box excited by internal HEMP
disturbance . 21
Figure 7 – A general shield excited by current injection . 22
Figure 8 – Basic configuration for transfer impedance measurement . 24
Figure 9 – Measured transfer impedance magnitude and phase of transfer impedance
per unit length for four braided shield cables with good shielding properties . 25
Figure 10 – Basic configuration for transfer admittance measurement . 26
Figure 11 – Test configuration for transfer impedance measurement of a cable
connector . 26
Figure 12 – Examples of conducting gaskets used as HEMP protection devices . 28
Figure 13 – Circuit model representing the behaviour of a conducting gasket for HEMP
protection . 28
Figure 14 – Measurement configuration for the resistivity of a sample . 29
Figure 15 – Test concept for measuring the resistivity with surface probes . 30
Figure 16 – Concepts for shielding effectiveness measurement of conducting sheets
and screens . 32
Figure 17 – Example of the calculated plane-wave shielding effectiveness of a
0,01 mm thick plate of different material as a function of frequency . 32
Figure 18 – Cut-off waveguides and honeycomb used as protective elements . 33
Figure 19 – Examples of full-scale, pulse-radiating HEMP simulators. 37
Figure 20 – Test procedure for the pulse test . 39
Figure 21 – Typical configuration of a CW test facility . 40
Figure 22 – Example CW measurement set-up . 41
Figure 23 – Test and analysis procedures for conducting a CW test. 42
Figure 24 – Analysis flow diagram for extrapolating a measured CW spectrum to the
HEMP response . 43
Figure 25 – Example scan from 9 kHz to 3 GHz for the ambient electromagnetic field
from communication signals . 44
Figure 26 – Test procedure for the ambient EM excitation test . 45
Figure 27 – Double-ended TEM cell for field illumination testing of small enclosures . 46
Figure 28 – Example test set-up for field illumination in the TEM cell . 47
Figure 29 – Illustration of the single-ended TEM cell and associated equipment . 48
Figure 30 – Test set-up for the plane-wave shielding effectiveness measurements . 50
Figure 31 – Test set-up for the H-field shielding effectiveness measurements . 51
Figure 32 – Example of antenna locations for the localized antenna tests for a
hypothetical shielded enclosure or facility . 52
Figure 33 – Test concept and equipment configuration for current injection testing of a
shielded enclosure or box . 56
Figure 34 – Surface probe for volume resistivity measurement . 59
Figure A.1 – Sample HEMP interaction diagram illustrating penetration mechanisms,
system responses and generic test interface locations . 64
Figure B.1 – Geometry of a shielded coaxial line with an internal circuit . 67
Figure B.2 – Coaxial cable located over a conducting ground plane . 68
Figure B.3 – Two per-unit-length circuits formed by the sheath and its ground return,
and the sheath and the internal conductor . 69

Figure C.1 – Magnetic field sensors [23] . 73
Figure C.2 – Single-slot, cylindrical coil sensor [23] . 73
Figure C.3 – Two- and four-slot cylindrical coil sensors [23] . 74
Figure C.4 – Electrical configuration of an E-field sensor [23] . 74
Figure C.5 – Biconical E-field sensor . 75
Figure C.6 – E-field sensor mounted on a conducting ground plane [23] . 75
Figure C.7 – Equipotential shapes for an optimally designed E-field sensor [23] . 75
Figure C.8 – Rogowski coil used for current measurements [23] . 76
Figure C.9 – Toroidal current sensor made of magnetic material [23] . 76
Figure C.10 – Voltage pick-up points on the edges of the toroidal sensor [23] . 76
Figure C.11 – Example of a single-channel fibre optic transmission system [23] . 77
Figure C.12 – Attenuation of coaxial lines and fibre optic cables as a function of
frequency . 78
Figure D.1 – Various antennas for CW testing. 81
Figure D.2 – Relationship between the CW antenna and the incident HEMP field . 82
Figure D.3 – Incident and ground-reflected field contributions to the reference sensor
excitations . 84
Figure D.4 – Measured reference H-field spectrum and its inverse Fourier transform . 85
Figure D.5 – Measured sensor responses and calibration function . 87
Figure D.6 – Measured transfer function, corrected by calibration file . 87
Figure E.1 – Example of a general shielding problem . 89
Figure E.2 – Behaviour of the impedance ratio EH as a function of distance from a
source [29] . 90
Figure E.3 – Conducting slab of thickness, d, and infinite extent serving as an
electromagnetic barrier . 91
Figure E.4 – Equivalent circuit representation of the shielding problem . 92
Figure E.5 – Two-port representation of a circuit . 93
Figure F.1 – Test set-up for the outside-to-in and inside-to-out SE measurement . 100

Table 1 – Recommended test procedure for different test objects . 34
Table 2 – Dimensions and composition of distances d to d , with reference to Figure 30 . 50
1 3
Table 3 – Dimensions and composition of distances d to d , with reference to Figure 31 . 51
1 3
Table 4 – Measurement frequencies and antennas in plane-wave . 52
Table 5 – Measurement frequencies and antennas in magnetic field . 54
Table E.1 – Surface resistance and electrical parameters for selected materials . 95
Table F.1 – Comparison with other standards . 98
Table F.2 – Test shielded rooms . 99
Table F.3 – Comparison of the SE measurement results . 101

– 6 – IEC 61000-4-23:2016 © IEC 2016
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ELECTROMAGNETIC COMPATIBILITY (EMC) –

Part 4-23: Testing and measurement techniques –
Test methods for protective devices for HEMP
and other radiated disturbances

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
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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 61000-4-23 has been prepared by subcommittee 77C: High power
transient phenomena, of IEC technical committee 77: Electromagnetic compatibility.
It forms Part 4-23 of IEC 61000. It has the status of a basic EMC publication in accordance
with IEC Guide 107.
This second edition cancels and replaces the first edition published in 2000. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) updates to the shielding effectiveness (SE) test method in Clause 5;
b) a new Annex F describing methods for testing ‘inside-to-out’ has been added.

The text of this standard is based on the following documents:
CDV Report on voting
77C/253/CDV 77C/257/RVC
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts in the IEC 61000 series, published under the general title Electromagnetic
compatibility (EMC), can be found on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC website under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.

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.
– 8 – IEC 61000-4-23:2016 © IEC 2016
INTRODUCTION
IEC 61000 is published in separate parts, according to the following structure:
Part 1: General
General considerations (introduction, fundamental principles)
Definitions, terminology
Part 2: Environment
Description of the environment
Classification of the environment
Compatibility levels
Part 3: Limits
Emission limits
Immunity limits (in so far as they do not fall under the responsibility of the product
committees)
Part 4: Testing and measurement techniques
Measurement techniques
Testing techniques
Part 5: Installation and mitigation guidelines
Installation guidelines
Mitigation methods and devices
Part 6: Generic Standards
Part 9: Miscellaneous
Each part is further subdivided into several parts, published either as international standards,
as technical specifications or technical reports, some of which have already been published
as sections. Others will be published with the part number followed by a dash and a second
number identifying the subdivision (example: IEC 61000-6-1).
The IEC has initiated the preparation of standardized methods to protect civilian society from
the effects of high power electromagnetic (HPEM) environments. Such effects could disrupt
systems for communications, electric power, information technology, etc.
This part of IEC 61000 is an international standard that establishes the test concepts, set-ups,
required equipment, and test procedures for protective devices against HEMP radiated
disturbances.
Annex F provides examples of the SE test method placing the TX antenna inside the barrier.

ELECTROMAGNETIC COMPATIBILITY (EMC) –

Part 4-23: Testing and measurement techniques –
Test methods for protective devices for HEMP
and other radiated disturbances

1 Scope
This part of IEC 61000 provides a protective devices test method for HEMP and other
radiated disturbances. It is primarily intended for HEMP testing but can be applied to other
externally generated radiated disturbances where appropriate. It provides a brief description
of the most important concepts for testing of shielding elements. For each test, the following
basic information is provided:
– theoretical foundation of the test (the test concepts);
– test set-up including outside-to-in and inside-to-out measurements;
– required equipment;
– test procedures;
– data processing.
This international standard does not provide information on requirements for specific levels
for testing.
This part of IEC 61000 has been updated to include a new test method.
Due to the available space, a transmitting antenna position outside the barrier has mainly
been suggested. However, nowadays, many EMP protection facilities in practical use do not
actually have enough space available outside the electromagnetic barrier due to physical
constraints such as concrete walls or soil to allow the method described in IEC 61000-4-
23:2000 (edition 1) to be applied correctly. From experience many facilities have available
space for a 1 m separation or less only.
Therefore, in many practical cases it is not possible to measure shielding effectiveness
according to the test method of previous documents. The constructors for EMP protection
facilities are also unwilling to build facilities with extra space for measurements with the
transmitting antenna outside the barrier due to the great expense and inefficiency of the
operational working area for new or existing buildings.
This document provides additionally a method that allows the transmitting antenna to be
placed inside the enclosure and the receiving antenna outside the barrier (‘inside-to-out’
method). Annex F includes test set-up and procedure examples.
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 60050-161, International Electrotechnical Vocabulary (IEV) – Part 161: Electromagnetic
compatibility (available at www.electropedia.org)

– 10 – IEC 61000-4-23:2016 © IEC 2016
IEC 61000-2-9, Electromagnetic compatibility (EMC) – Part 2: Environment – Section 9:
Description of HEMP environment – Radiated disturbance
IEC 61000-5-3, Electromagnetic compatibility (EMC) – Part 5-3: Installation and mitigation
guidelines – HEMP protection concepts
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60050-161, as well
as the following apply.
3.1
aperture
opening in an electromagnetic barrier (shield) through which EM fields may penetrate
3.2
aperture point-of-entry
intentional or inadvertent holes, cracks, openings or other discontinuities in a shield surface
Note 1 to entry: Intentional aperture points-of-entry are provided for personnel and/or equipment entry and egress
and for ventilation through an electromagnetic barrier.
3.3
attenuation
reduction in magnitude (as a result of absorption and scattering) of an electric or magnetic
field, a current or a voltage, usually expressed in decibels
3.4
bandwidth (of a device)
width of a frequency band over which a given characteristic of an equipment or transmission
channel does not differ from its reference value by more than a specified amount or ratio
[SOURCE: IEC 60050-161:1990, 161-06-09, modified – the note has been deleted.]
3.5
bandwidth (of an emission or signal)
width of the frequency band outside which the level of any spectral component does not
exceed a specified percentage of a reference level
[SOURCE: IEC 60050-161:1990, 161-06-10]
3.6
bounded wave simulator
type of simulator for producing electromagnetic fields in a localized region of space referred to
as a "test volume"
3.7
box
enclosure that contains electrical equipment
Note 1 to entry: Such boxes usually contain modules of subsystems.
3.8
broadband
3.8.1
broadband
emission which has a bandwidth greater than that of a particular measuring
apparatus or receiver
3.8.2
broadband device
device whose bandwidth is such that it is able to accept and process all the spectral
components of a particular emission
[SOURCE: IEC 60050-161:1990, 161-06-12]
3.9
circuit
collection of interconnected electronics forming one or more closed paths
3.10
conductive point-of-entry
electrical wire or cable or other conductive object, such as a metal rod, which passes through
the electromagnetic barrier
3.11
coupling
interaction of electromagnetic fields with electrical systems, whereby part of the energy of the
field is transferred to the system
3.12
current injection test
test technique by which, through some external means, a current is forced to flow in a circuit
at a desired location
Note 1 to entry: For EMP testing purposes, it is a process by which simulated EMP transient current pulses are
introduced into a component, circuit or system to measure damage or upset thresholds.
3.13
cut-off frequency
lowest frequency for which there is no attenuation of the electromagnetic fields
propagating in a lossless waveguide
Note 1 to entry: Below this frequency, the fields attenuate exponentially with distance along the waveguide.
3.14
dipole
straight antenna, usually fed in the center, that produces maximum radiation in a plane normal
to its principal axis
3.15
direct drive
excitation of an electrical system by directly applying a voltage or current source (either
transient or continuous wave) to system cables or surfaces as a means of simulating the
effects of transient EM pulses
Note 1 to entry: See current injection test (3.12).
3.16
direct field penetration
penetration of the system shielding by the EM field
3.17
direction of propagation
direction of the electromagnetic plane-wave propagation vector k, which is perpendicular to
the plane containing the vectors of the electric and the magnetic fields

– 12 – IEC 61000-4-23:2016 © IEC 2016
3.18
electric field strength
E
magnitude of the electric field vector of an electromagnetic wave or of a field created by an
electric charge distribution, measured in volt per meter
3.19
electromagnetic barrier
shield
topologically closed surface made to prevent or limit EM fields and conducted transients from
entering the enclosed space
Note 1 to entry: The barrier consists of the shield surface and PoE treatments and it encloses the protected
volume.
3.20
electromagnetic disturbance
any electromagnetic phenomenon which may degrade the performance of a device,
equipment or system, or adversely affect living or inert matter
[SOURCE: IEC 60050-161:1990, 161-01-05]
3.21
electromagnetic environment
totality of electromagnetic phenomena existing at a given location
[SOURCE: IEC 60050-161:1990, 161-01-01, modified – the note has been deleted.]
3.22
electromagnetic pulse
EMP
all types of electromagnetic fields produced by a nuclear explosion
Note 1 to entry: Electromagnetic pulse is also referred to as nuclear electromagnetic pulse (NEMP).
3.23
(electromagnetic) radiation
a) phenomenon by which energy in the form of electromagnetic waves emanates from a
source into space
b) energy transferred through space in the form of electromagnetic waves
[SOURCE: IEC 60050-161:1990, 161-01-10, modified – the note has been deleted.]
3.24
electromagnetic topology
description of the interconnection of shields or electromagnetic barriers in a system that limit
the EMP environment within the system
3.25
external coupling
process by which an incident electromagnetic field strikes the exterior portions of a
conducting system enclosure and induces currents and charges
3.26
gasket
element, normally electrically conductive and flexible, used to seal an aperture in an
enclosure
3.27
inside-to-out
test method where the transmitting antenna is placed inside and the receiving antenna is
placed outside the shielded enclosure
3.28
hardening
process of decreasing the vulnerability of a system or component by design techniques, for
example by protecting against, or decoupling from, an undesirable external environment such
as EMP
3.29
high-altitude electromagnetic pulse
HEMP
electromagnetic pulse produced when a nuclear explosion occurs outside the earth's
atmosphere, typically above an altitude of 30 km
3.30
hyperband
spectrum of EM field with a band ratio greater than 10
3.31
impulse radiating antenna
IRA
half IRA
full IRA
full IRA with a full parabolic dish or half IRA with a divided parabolic dish on a conducting
ground plane and an impedance transformer from 50 Ω to 100 Ω
3.32
inside-to-out
alternative test method where the receiving antenna is placed outside and the transmitting
antenna is placed inside of the shielded enclosure
3.33
magnetic field strength
H
magnitude of the magnetic field vector of an electromagnetic wave, or the field produced by a
current flowing in a wire, loop antenna, etc., measured in amperes per meter
3.34
outside-to-in
conventional test method where the receiving antenna is placed inside and the transmitting
antenna is placed outside of the shielded enclosure
3.35
overall shielding
global shielding
protection of an entire entity by use of a single shielding enclosure or some practical
equivalent, such as the protection of the contents of an entire building by shielding the entire
building
3.36
penetration
transfer of electromagnetic energy through an electromagnetic barrier from one volume to
another
– 14 – IEC 61000-4-23:2016 © IEC 2016
Note 1 to entry: This can occur by field diffusion through the barrier, by field leakage through apertures, and by
electrical current passing through conductors connecting the two volumes (wires, cables, conduits, pipes, ducts,
etc.).
3.37
point-of-entry
PoE
physical location (point/port) on the electromagnetic barrier, where EM energy may enter or
exit a topological volume, unless an adequate PoE protective device is provided
Note 1 to entry: A PoE is not limited to a geometrical point. PoEs are classified as aperture PoEs or conductor
PoEs according to the type of penetration. They are also classified as architectural, mechanical, structural or
electrical PoEs according to the architectural engineering discipline in which they are usually encountered.
3.38
PoE protective device
PoE treatment
protective measure used to prevent or limit EM energy from entering a protected volume at a
PoE
Note 1 to entry: Common PoE protective devices include waveguides below cut-off, closure plates for aperture
PoEs, and filters and surge arresters on penetrating conductors.
3.39
protected volume
three-dimensional space enclosed by an electromagnetic barrier
3.40
pulse
abrupt variation of short duration of a physical quantity followed by a rapid return to the initial
value
[SOURCE: IEC 60050-161:1990, 161-02-02]
3.41
radio frequency
RF
frequency of the electromagnetic spectrum that is between the audio frequency portion and
the infrared portion
Note 1 to entry: Sometimes, audio frequencies are considered to be included as part of the RF spectrum.
3.42
penetrating field
field inside the shielded volume that may penetrate via shield imperfections
3.43
shielded enclosure
screened room
mesh or sheet metallic housing designed expressly for the purpose of separating
electromagnetically the internal and external environment
[SOURCE: IEC 60050-161:1990, 161-04-37]
3.44
shielding degradation
general or localized reduction of electromagnetic shielding effectiveness as a result of
openings, penetrations, wear, improper utilization, etc.

3.45
shielding effectiveness
SE
measure of the reduction or attenuation in the electromagnetic field strength at a point in
space caused by the insertion of a shield between the source and that point, usually
expressed in decibels (dB)
3.46
skin effect
tendency of alternating current to concentrate in the surface layer of a conductor, resulting in
the effective resistance of the conductor increasing with frequency
3.47
system
collection of equipment, subsystems, skilled personnel, and techniques capable of performing
or supporting a defined operational role
Note 1 to entry: A complete system includes related facilities, equipment, subsystems, materials, servi
...