CISPR 16-2-2:2010

CISPR 16-2-2 ®
Edition 2.0 2010-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
INTERNATIONAL SPECIAL COMMITTEE ON RADIO INTERFERENCE
COMITÉ INTERNATIONAL SPÉCIAL DES PERTURBATIONS RADIOÉLECTRIQUES
BASIC EMC PUBLICATION
PUBLICATION FONDAMENTALE EN CEM
Specification for radio disturbance and immunity measuring apparatus
and methods –
Part 2-2: Methods of measurement of disturbances and immunity –
Measurement of disturbance power

Spécifications des méthodes et des appareils de mesure des perturbations
radioélectriques et de l'immunité aux perturbations radioélectriques –
Partie 2-2: Méthodes de mesure des perturbations et de l'immunité –
Mesure de la puissance perturbatrice

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CISPR 16-2-2 ®
Edition 2.0 2010-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
INTERNATIONAL SPECIAL COMMITTEE ON RADIO INTERFERENCE
COMITÉ INTERNATIONAL SPÉCIAL DES PERTURBATIONS RADIOÉLECTRIQUES
BASIC EMC PUBLICATION
PUBLICATION FONDAMENTALE EN CEM
Specification for radio disturbance and immunity measuring apparatus
and methods –
Part 2-2: Methods of measurement of disturbances and immunity –
Measurement of disturbance power

Spécifications des méthodes et des appareils de mesure des perturbations
radioélectriques et de l'immunité aux perturbations radioélectriques –
Partie 2-2: Méthodes de mesure des perturbations et de l'immunité –
Mesure de la puissance perturbatrice

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
X
CODE PRIX
ICS 33.100.10; 33.100.20 ISBN 978-2-88912-097-0
– 2 – CISPR 16-2-2 © IEC:2010
CONTENTS
FOREWORD.5
1 Scope.7
2 Normative references.7
3 Terms and definitions .7
4 Types of disturbance to be measured.12
4.1 General .12
4.2 Types of disturbance .12
4.3 Detector functions .12
5 Connection of measuring equipment .13
5.1 General .13
5.2 Connection of ancillary equipment.13
6 General measurement requirements and conditions .13
6.1 General .13
6.2 Disturbance not produced by the equipment under test .13
6.2.1 General .13
6.2.2 Compliance testing .13
6.3 Measurement of continuous disturbance .13
6.3.1 Narrowband continuous disturbance.13
6.3.2 Broadband continuous disturbance.14
6.3.3 Use of spectrum analyzers and scanning receivers.14
6.4 Operating conditions of the EUT .14
6.4.1 General .14
6.4.2 Normal load conditions.14
6.4.3 The time of operation.14
6.4.4 Running-in time .14
6.4.5 Supply .14
6.4.6 Mode of operation.14
6.5 Interpretation of measuring results.14
6.5.1 Continuous disturbance .14
6.5.2 Discontinuous disturbance .15
6.5.3 Measurement of the duration of disturbances .15
6.6 Measurement times and scan rates for continuous disturbance .15
6.6.1 General .15
6.6.2 Minimum measurement times .15
6.6.3 Scan rates for scanning receivers and spectrum analyzers .16
6.6.4 Scan times for stepping receivers .17
6.6.5 Strategies for a spectrum overview using the peak detector.18
6.6.6 Timing considerations using FFT-based instruments .21
7 Measurements using the absorbing clamp.23
7.1 Introduction to ACMM .23
7.2 Application of the absorbing clamp measurement method .24
7.2.1 General .24
7.2.2 Frequency range.24
7.2.3 EUT unit dimensions.24
7.2.4 LUT requirements .24
7.3 Requirements for measurements instrumentation and test site .24

CISPR 16-2-2 © IEC:2010 – 3 –
7.3.1 General .24
7.3.2 Measuring receiver .24
7.3.3 Absorbing clamp assembly.24
7.3.4 Absorbing clamp test site requirements .25
7.4 Ambient requirements.26
7.5 EUT leads requirements .26
7.5.1 General .26
7.5.2 Lead under test.26
7.5.3 Leads not under test .27
7.6 Test set-up requirements .27
7.6.1 General .27
7.6.2 EUT set-up .27
7.6.3 LUT set-up.28
7.6.4 Absorbing clamp .29
7.6.5 Measurement cable.29
7.7 Operating conditions of the EUT .29
7.8 Measurement procedure .29
7.8.1 Ambient measurement procedure.29
7.8.2 EUT measurement procedure .29
7.9 Determination of disturbance power .31
7.10 Determination of the measurement uncertainty.31
7.11 Compliance criteria.31
8 Automated measurement of emissions.32
8.1 Precautions for automating measurements.32
8.2 Generic measurement procedure .32
8.3 Prescan measurements .33
8.3.1 Purpose.33
8.3.2 Determination of the required measurement time .33
8.3.3 Defining the prescan measurement .33
8.4 Data reduction .34
8.5 Emission maximization and final measurement .34
8.6 Post processing and reporting.34
8.7 Emission measurement strategies with FFT-based measuring instruments .34
Annex A (informative) Historical background to the method of measurement of the
interference power produced by electrical household and similar appliances in the VHF
range (see 7.1) .35
Annex B (informative) Use of spectrum analyzers and scanning receivers (see Clause 6) .38
Annex C (informative) Scan rates and measurement times for use with the average
detector .41
Annex D (normative) Determination of suitability of spectrum analyzers for compliance
tests.45
Bibliography .46

Figure 1 – Measurement of a combination of a CW signal (“NB”) and an impulsive
signal (“BB”) using multiple sweeps with maximum hold.18
Figure 2 – Example of a timing analysis.19
Figure 3 – A broadband spectrum measured with a stepped receiver .20
Figure 4 – Intermittent narrowband disturbances measured using fast short repetitive
sweeps with maximum hold function to obtain an overview of the emission spectrum .20

– 4 – CISPR 16-2-2 © IEC:2010
Figure 5 – FFT scan in segments .22
Figure 6 – Frequency resolution enhanced by FFT-based measuring instrument .23
Figure 7 – Schematic drawing of the absorbing clamp measurement method .25
Figure 8 – Side view of the absorbing clamp measurement set-up for table top EUTs .28
Figure 9 – Side view of the absorbing clamp measurement set-up for floor standing
EUTs .28
Figure 10 – Process for reduction in measurement time.32
Figure C.1 – Weighting function of a 10 ms pulse for peak (“PK”) and average
detections with (“CISPR AV”) and without (“AV”) peak reading; meter time constant
160 ms.43
Figure C.2 – Weighting functions of a 10 ms pulse for peak (“PK”) and average
detections with (“CISPR AV”) and without (“AV”) peak reading; meter time constant
100 ms.43
Figure C.3 – Example of weighting functions (of a 1 Hz pulse) for peak (“PK”) and
average detections as a function of pulse width: meter time constant 160 ms.44
Figure C.4 – Example of weighting functions (of a 1 Hz pulse) for peak (“PK”) and
average detections as a function of pulse width: meter time constant 100 ms.44

Table 1 – Minimum measurement times for the four CISPR bands .16
Table 2 – Minimum scan times for the three CISPR bands with peak and quasi-peak
detectors.16
Table 3 – Sample scheme for an absorbing clamp measurement with an upper
frequency bound of 300 MHz.30
Table 4 – Sample scheme for an absorbing clamp measurement with an upper
frequency bound of 1 000 MHz .31
Table B.1 – Minimum sweep time/fastest scan rates.39
Table C.1 – Pulse suppression factors and scan rates for a 100 Hz video bandwidth.42
Table C.2 – Meter time constants and the corresponding video bandwidths and
maximum scan rates .42
Table D.1 – Maximum amplitude difference between peak and quasi-peak detected
signals .45

CISPR 16-2-2 © IEC:2010 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
INTERNATIONAL SPECIAL COMMITTEE ON RADIO INTERFERENCE
____________
SPECIFICATION FOR RADIO DISTURBANCE AND IMMUNITY
MEASURING APPARATUS AND METHODS –

Part 2-2: Methods of measurement of disturbances and immunity –
Measurement of disturbance power

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
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5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
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6) All users should ensure that they have the latest edition of this publication.
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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 CISPR 16-2-2 has been prepared by CISPR subcommittee A: Radio-
interference measurements and statistical methods, in cooperation with CISPR subcommittee
D: Electromagnetic disturbances related to electric/electronic equipment on vehicles and
internal combustion engine powered devices.
This second edition cancels and replaces the first edition (2003), its Amendment 1 (2004) and
Amendment 2 (2005). It constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition: provisions for the use of spectrum analyzers for compliance measurements (Annex D)
and the use of FFT-based test instrumentation (Clauses 3, 6 and 8) are now included.

– 6 – CISPR 16-2-2 © IEC:2010
It has the status of a basic EMC publication in accordance with IEC Guide 107,
Electromagnetic compatibility – Guide to the drafting of electromagnetic compatibility
publications.
The text of this standard is based on the following documents:
CDV Report on voting
CISPR/A/877/CDV CISPR/A/896/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 of the CISPR 16 series can be found on the IEC website under the general
title Specification for radio disturbance and immunity measuring apparatus and methods.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC web site 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.
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 publication using a colour printer.

CISPR 16-2-2 © IEC:2010 – 7 –
SPECIFICATION FOR RADIO DISTURBANCE AND IMMUNITY
MEASURING APPARATUS AND METHODS –

Part 2-2: Methods of measurement of disturbances and immunity –
Measurement of disturbance power

1 Scope
This part of CISPR 16 specifies the methods of measurement of disturbance power using the
absorbing clamp in the frequency range 30 MHz to 1 000 MHz.
NOTE In accordance with IEC Guide 107, CISPR 16-2-2 is a basic EMC publication for use by product
committees of the IEC. As stated in Guide 107, product committees are responsible for determining the
applicability of the EMC standard. CISPR and its sub-committees are prepared to co-operate with product
committees in the determination of the value of particular EMC tests for specific products.
2 Normative references
The following referenced documents are indispensable for the application 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.
CISPR 16-1-1:2010, Specification for radio disturbance and immunity measuring apparatus
and methods – Part 1-1: Radio disturbance and immunity measuring apparatus – Measuring
apparatus
CISPR 16-1-3:2004, Specification for radio disturbance and immunity measuring apparatus
and methods – Part 1-3: Radio disturbance and immunity measuring apparatus – Ancillary
equipment – Disturbance power
CISPR 16-1-4, Specification for radio disturbance and immunity measuring apparatus and
methods – Part 1-4: Radio disturbance and immunity measuring apparatus – Antennas and
test sites for radiated disturbance measurements
CISPR 16-4-2, Specification for radio disturbance and immunity measuring apparatus and
methods – Part 4-2: Uncertainties, statistics and limit modelling – Uncertainty in EMC
measurements
IEC 60050-161:1990, International Electrotechnical Vocabulary (IEV) – Part 161:
Electromagnetic compatibility
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
absorbing clamp measurement method
ACMM
method for measurement of disturbance power of an equipment under test (EUT) by using an
absorbing clamp device that is clamped around the lead(s) of the EUT

– 8 – CISPR 16-2-2 © IEC:2010
3.2
absorbing clamp test site
ACTS
test site that is validated to perform disturbance power measurements by using the absorbing
clamp measurement method (ACMM)
3.3
ancillary equipment
transducers (e.g. current and voltage probes and artificial networks) connected to a measuring
receiver or (test) signal generator and used in the disturbance signal transfer between the EUT
and the measuring or test equipment
3.4
clamp factor
CF
F
c
ratio of the disturbance power of an EUT to the received voltage at the output of the absorbing
clamp
NOTE The clamp factor is a transducer factor of the absorbing clamp.
3.5
clamp reference point
CRP
indication on the outside of the absorbing clamp that is related to the longitudinal position of
the front edge of the current transformer within the clamp and is used to define the horizontal
position of the clamp during the measurement
3.6
coaxial cable
cable containing one or more coaxial lines, typically used for a matched connection of ancillary
equipment to the measuring equipment or (test-)signal generator providing a specified
characteristic impedance and a specified maximum allowable cable transfer impedance
3.7
common mode (asymmetrical) disturbance voltage
RF voltage between the artificial midpoint of a two-conductor line and reference ground, or in
case of a bundle of lines, the effective RF disturbance voltage of the whole bundle (vector sum
of the unsymmetrical voltages) against the reference ground measured with a clamp (current
transformer) at a defined terminating impedance
NOTE See also IEC 60050-161, 161-04-09.
3.8
common mode current
the vector sum of the currents flowing through two or more conductors at a specified cross-
section of a "mathematical" plane intersected by these conductors
3.9
continuous disturbance
RF disturbance with a duration of more than 200 ms at the IF-output of a measuring receiver,
which causes a deflection on the meter of a measuring receiver in quasi-peak detection mode
which does not decrease immediately
[IEC 60050-161, 161-02-11, modified]

CISPR 16-2-2 © IEC:2010 – 9 –
3.10
discontinuous disturbance
for counted clicks, disturbance with a duration of less than 200 ms at the IF-output of a
measuring receiver, which causes a transient deflection on the meter of a measuring receiver
in quasi-peak detection mode
NOTE For impulsive disturbance, see IEC 60050-161, 161-02-08.
3.11
(electromagnetic) emission
the phenomenon by which electromagnetic energy emanates from a source
[IEC 60050-161, 161-01-08]
3.12
emission limit (from a disturbing source)
the specified maximum emission level of a source of electromagnetic disturbance
[IEC 60050-161, 161-03-12]
3.13
EUT
equipment (devices, appliances and systems) subjected to EMC (emission) compliance tests
3.14
lead under test
LUT
lead, associated with an EUT, that is the subject of an emission or an immunity test
NOTE In general, an EUT may have one or more leads that are used for interconnections to the mains supply, or
other networks, or for interconnection to auxiliary equipment. These leads are generally electrical cables such as
mains cables, coaxial cables, data bus cables, etc.
3.15
measurement
process of experimentally obtaining one or more quantity values that can reasonably be
attributed to a quantity
[2.1 of ISO/IEC Guide 99] [6]
3.16
measurement, scan and sweep times

3.16.1
measurement time
T
m
effective, coherent time for a measurement result at a single frequency (in some areas also
called dwell time)
– for the peak detector, the effective time to detect the maximum of the signal envelope,
– for the quasi-peak detector, the effective time to measure the maximum of the weighted
envelope,
– for the average detector, the effective time to average the signal envelope,
– for the r.m.s. detector, the effective time to determine the r.m.s. of the signal envelope
———————
Numbers in square brackets refer to the Bibliography.

– 10 – CISPR 16-2-2 © IEC:2010
3.16.2
observation time
T
o
sum of measurement times T on a certain frequency in case of multiple sweeps; if n is the
m
number of sweeps or scans, then T = n × T
o m
3.16.3
scan
continuous or stepped frequency variation over a given frequency span
3.16.4
span
Δf
difference between stop and start frequencies of a sweep or scan
3.16.5
sweep
continuous frequency variation over a given frequency span
3.16.6
sweep rate
scan rate
frequency span divided by the sweep or scan time
3.16.7
sweep time
scan time
T
s
time between start and stop frequencies of a sweep or scan
3.16.8
total observation time
T
tot
effective time for an overview of the spectrum (either single or multiple sweeps). If c is the
number of channels within a scan or sweep, then T = c × n × T
tot m
3.17
measuring receiver
instrument such as a tunable voltmeter, an EMI receiver, a spectrum analyzer or an FFT-
based measuring instrument, with or without preselection, that meets the relevant clauses of
CISPR 16-1-1
NOTE See Annex I of CISPR 16-1-1 for further information.
3.18
number of sweeps per time unit (e.g. per second)
n
s
1/(sweep time + retrace time)
3.19
product publication
publication specifying EMC requirements for a product or product family, taking into account
specific aspects of such a product or product family

CISPR 16-2-2 © IEC:2010 – 11 –

3.20
slide reference point
SRP
end of the clamp slide where the EUT is located and which is used to define the horizontal
distance to the clamp reference point (CRP) of the absorbing clamp during the measurement
procedure
3.21
test
technical operation that consists of the determination of one or more characteristics of a given
product, process or service according to a specified procedure
NOTE A test is carried out to measure or classify a characteristic or a property of an item by applying to the item
a set of environmental and operating conditions and/or requirements.
[IEC 60050-151, 151-16-13] [5]
3.22
test configuration
combination that gives the specified measurement arrangement of the EUT in which an
emission level is measured
3.23
weighting (of e.g. impulsive disturbance)
pulse-repetition-frequency (PRF) dependent conversion (mostly reduction) of a peak-detected
impulse voltage level to an indication that corresponds to the interference effect on radio
reception
NOTE 1 For the analogue receiver, the psychophysical annoyance of the interference is a subjective quantity
(audible or visual, usually not a certain number of misunderstandings of a spoken text).
NOTE 2 For the digital receiver, the interference effect is an objective quantity that may be defined by the critical
bit error ratio (BER) or bit error probability (BEP) for which perfect error correction can still occur or by another,
objective and reproducible parameter.
3.23.1
weighted disturbance measurement
measurement of disturbance using a weighting detector
3.23.2
weighting characteristic
peak voltage level as a function of PRF for a constant effect on a specific radiocommunication
system, i.e. the disturbance is weighted by the radiocommunication system itself
3.23.3
weighting detector
detector that provides an agreed weighting function
3.23.4
weighting factor
value of the weighting function relative to a reference PRF or relative to the peak value
NOTE Weighting factor is expressed in dB.

– 12 – CISPR 16-2-2 © IEC:2010
3.23.5
weighting function
weighting curve
relationship between input peak voltage level and PRF for constant level indication of a
measuring receiver with a weighting detector, i.e. the curve of response of a measuring
receiver to repeated pulses
4 Types of disturbance to be measured
4.1 General
This clause describes the classification of different types of disturbance and the detectors
appropriate for their measurement.
4.2 Types of disturbance
For physical and psychophysical reasons, dependent on the spectral distribution, measuring
receiver bandwidth, the duration, rate of occurrence, and degree of annoyance during the
assessment and measurement of radio disturbance, distinction is made between the following
types of disturbance:
a) narrowband continuous disturbance, i.e. disturbance on discrete frequencies as, for
example, the fundamentals and harmonics generated with the intentional application of RF
energy with ISM equipment, constituting a frequency spectrum consisting only of individual
spectral lines whose separation is greater than the bandwidth of the measuring receiver so
that during the measurement only one line falls into the bandwidth in contrast to b);
b) broadband continuous disturbance that normally is unintentionally produced by the
repeated impulses of, for example, commutator motors, and that has a repetition frequency
that is lower than the bandwidth of the measuring receiver so that during the measurement
more than one spectral line falls into the bandwidth; and
c) broadband discontinuous disturbance is also generated unintentionally by mechanical or
electronic switching procedures, for example by thermostats or programme controls with a
repetition rate lower than 1 Hz (click-rate less than 30/min).
The frequency spectra of b) and c) are characterized by having a continuous spectrum in the
case of individual (single) impulses and a discontinuous spectrum in case of repeated
impulses, both spectra being characterized by having a frequency range that is wider than the
bandwidth of the measuring receiver specified in CISPR 16-1-1.
4.3 Detector functions
Depending on the types of disturbance, measurements may be carried out using a measuring
receiver with:
a) an average detector generally used in the measurement of narrowband disturbance and
signals, and particularly to discriminate between narrowband and broadband disturbance;
b) a quasi-peak detector provided for the weighted measurement of broadband disturbance for
the assessment of audio annoyance to a radio listener, but also usable for narrowband
disturbance;
c) an rms-average detector provided for the weighted measurement of broadband disturbance
for the assessment of the effect of impulsive disturbance to digital radio communication
services but also useable for narrowband disturbance;
d) a peak detector that may be used for either broadband or narrowband disturbance
measurement.
Measuring receivers incorporating these detectors are specified in CISPR 16-1-1.

CISPR 16-2-2 © IEC:2010 – 13 –
5 Connection of measuring equipment
5.1 General
This subclause describes the connection of measuring equipment, measuring receivers and
ancillary equipment.
5.2 Connection of ancillary equipment
The connecting cable between the measuring receiver and the ancillary equipment (absorbing
clamp) shall be shielded and its characteristic impedance shall be matched to the input
impedance of the measuring receiver.
6 General measurement requirements and conditions
6.1 General
Radio disturbance measurements shall be:
a) reproducible, i.e. independent of the measurement location and environmental conditions,
especially ambient noise;
b) free from interactions, i.e. the connection of the EUT to the measuring equipment shall
neither influence the function of the EUT nor the accuracy of the measurement equipment.
These requirements may be met by observing the following conditions:
– existence of a sufficient signal-to-noise ratio at the desired measurement level, e.g. the
level of the relevant disturbance limit;
– having a defined measuring set-up, termination and operating conditions of the EUT.
6.2 Disturbance not produced by the equipment under test
6.2.1 General
The measurement signal-to-noise ratio with respect to ambient noise shall meet the following
requirements. Should the ambient noise level exceed the required level, it shall be recorded in
the test report.
6.2.2 Compliance testing
A test site shall permit emissions from the EUT to be distinguished from ambient noise. The
ambient noise level should preferably be 20 dB, but at least be 6 dB below the desired
measurement level. For the 6 dB condition, the apparent disturbance level from the EUT is
increased by up to 3,5 dB. The suitability of the site for required ambient level may be
determined by measuring the ambient noise level with the test unit in place but not operating.
In the case of compliance measurement according to a limit, the ambient noise level is
permitted to exceed the preferred –6 dB level provided that the level of both ambient noise and
source emanation combined does not exceed the specified limit. The EUT is then considered
to meet the limit. Other actions can also be taken; for example, reducing the bandwidth for
narrowband signals.
6.3 Measurement of continuous disturbance
6.3.1 Narrowband continuous disturbance
The measuring set shall be kept tuned to the discrete frequency under investigation and
returned if the frequency fluctuates.

– 14 – CISPR 16-2-2 © IEC:2010
6.3.2 Broadband continuous disturbance
For the assessment of broadband continuous disturbance the level of which is not steady, the
maximum reproducible measurement value shall be found. See 6.5.1 for further details.
6.3.3 Use of spectrum analyzers and scanning receivers
Spectrum analyzers and scanning receivers are useful for disturbance measurements,
particularly in order to reduce measuring time. However, special consideration shall be given
to certain characteristics of these instruments, which include: overload, linearity, selectivity,
normal response to pulses, frequency scan rate, signal interception, sensitivity, amplitude
accuracy and peak, average, rms-average and quasi-peak detection. These characteristics are
considered in Annex B.
6.4 Operating conditions of the EUT
6.4.1 General
The EUT shall be operated under the following conditions.
6.4.2 Normal load conditions
The normal load conditions shall be as defined in the product specification relevant to the
EUT, and for EUTs not so covered, as indicated in the manufacturer's instructions.
6.4.3 The time of operation
The time of operation shall be, in the case of EUTs with a given rated operating time, in
accordance with the marking; in all other cases, the time is not restricted.
6.4.4 Running-in time
No specific running-in time, prior to testing, is given, but the EUT shall be operated for a
sufficient period to ensure that the modes and conditions of operation are typical of those
during the life of the equipment. For some EUTs, special test conditions may be prescribed in
the relevant equipment publications.
6.4.5 Supply
The EUT shall be operated from a supply having the rated voltage of the EUT. If the level of
disturbance varies considerably with the supply voltage, the measurements shall be repeated
for supply voltages over the range of 0,9 to 1,1 times the rated voltage. EUTs with more than
one rated voltage shall be tested at the rated voltage that causes maximum disturbance.
6.4.6 Mode of operation
The EUT shall be operated under practical conditions that cause the maximum disturbance at
the measurement frequency.
6.5 Interpretation of measuring results
6.5.1 Continuous disturbance
a) If the level of disturbance is not steady, the reading on the measuring receiver is observed
for at least 15 s for each measurement; the highest readings shall be recorded, with the
exception of any isolated clicks, which shall be ignored (see 4.2 of CISPR 14-1 [2]) .
b) If the general level of the disturbance is not steady, but shows a continuous rise or fall of
more than 2 dB in the 15 s period, then the disturbance voltage levels shall be observed
for a further period and the levels shall be interpreted according to the conditions of normal
use of the EUT, as follows:
CISPR 16-2-2 © IEC:2010 – 15 –
1) if the EUT is one that may be switched on and off frequently, or the direction of rotation
of which can be reversed, then at each frequency of measureme
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