CISPR TR 16-4-1:2003/AMD2:2007

Amendment 2 - Specification for radio disturbance and immunity measuring apparatus and methods - Part 4-1: Uncertainties, statistics and limit modelling - Uncertainties in standardized EMC tests

General Information

• Status: Published
• Publication Date: 26-Apr-2007
• ICS: 33.100.10 - Emission
• ICS: 33.100.20 - Immunity
• Technical Committee: CIS/A - Radio-interference measurements and statistical methods
• Current Stage: DELPUB - Deleted Publication
• Completion Date: 23-Feb-2009

Relations

• Amends: CISPR TR 16-4-1:2003 - Specification for radio disturbance and immunity measuring apparatus and methods - Part 4-1: Uncertainties, statistics and limit modelling - Uncertainties in standardized EMC tests
• Effective Date: 05-Sep-2023
• Revised: CISPR TR 16-4-1:2009 - Specification for radio disturbance and immunity measuring apparatus and methods - Part 4-1: Uncertainties, statistics and limit modelling - Uncertainties in standardized EMC tests
• Effective Date: 05-Sep-2023

Standards Content (Sample)

TECHNICAL CISPR
REPORT 16-4-1
AMENDMENT 2
2007-04
INTERNATIONAL SPECIAL COMMITTEE ON RADIO INTERFERENCE
Amendment 2
Specification for radio disturbance and immunity
measuring apparatus and methods –
Part 4-1:
Uncertainties, statistics and limit modelling –
Uncertainties in standardized EMC tests

Reference number
CISPR 16-4-1 Amend. 2:2007(E)
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form

or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester.
If you have any questions about IEC copyright or have an enquiry about obtaining additional rights to this publication,
please contact the address below or your local IEC member National Committee for further information.

IEC Central Office
3, rue de Varembé
CH-1211 Geneva 20
Switzerland
Email: [e-mail]
Web: www.iec.ch
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigenda or an amendment might have been published.
ƒ Catalogue of IEC publications: www.iec.ch/searchpub
The IEC on-line Catalogue enables you to search by a variety of criteria (reference number, text, technical committee,…).
It also gives information on projects, withdrawn and replaced publications.
ƒ IEC Just Published: www.iec.ch/online_news/justpub
Stay up to date on all new IEC publications. Just Published details twice a month all new publications released. Available
on-line and also by email.
ƒ Customer Service Centre: www.iec.ch/webstore/custserv
If you wish to give us your feedback on this publication or need further assistance, please visit the Customer Service
Centre FAQ or contact us:
Email: [e-mail]
Tel.: [phone]
Fax: [phone]
TECHNICAL CISPR
REPORT 16-4-1
AMENDMENT 2
2007-04
INTERNATIONAL SPECIAL COMMITTEE ON RADIO INTERFERENCE
Amendment 2
Specification for radio disturbance and immunity
measuring apparatus and methods –
Part 4-1:
Uncertainties, statistics and limit modelling –
Uncertainties in standardized EMC tests

PRICE CODE
Commission Electrotechnique Internationale V
International Electrotechnical Commission
МеждународнаяЭлектротехническаяКомиссия
For price, see current catalogue

– 2 – TR CISPR 16-4-1 Amend. 2 © IEC:2007(E)

FOREWORD
This amendment has been prepared by CISPR subcommittee A: Radio-interference

measurements and statistical methods.

The text of this amendment is based on the following documents:

DTR Report on voting
CISPR/A/713/DTR CISPR/A/729/RVC

Full information on the voting for the approval of this amendment can be found in the report
on voting indicated in the above table.
The committee has decided that the contents of this amendment and the base publication will
remain unchanged until the maintenance result 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.
A bilingual version of this publication may be issued at a later date.
_____________
Page 10
2 Normative references
Add the following new references:
CISPR 16-1-4:2007, Specification for radio disturbance and immunity measuring apparatus

and methods - Part 1-4: Radio disturbance and immunity measuring apparatus - Ancillary
equipment - Radiated disturbances
CISPR 16-2-3:2006, Specification for radio disturbance and immunity measuring apparatus
and methods - Part 2-3: Methods of measurement of disturbances and immunity - Radiated
disturbance measurements
Page 11
3 Terms and definitions
Replace the existing heading of Clause 3 by the following:

TR CISPR 16-4-1 Amend. 2 © IEC:2007(E) – 3 –

3 Terms, definitions, and acronyms

Add new subclause 3.1 as follows, and renumber terms 3.1 to 3.20 as 3.1.1 to 3.1.20:

3.1 Terms and definitions
Add, on page 14, the following new subclause:

3.2 Acronyms
AF antenna factor
EUT equipment under test
GUM ISO/IEC Guide to the expression of uncertainty in measurement
ILC interlaboratory comparison
LPDA log-periodic dipole array
MIU measurement instrumentation uncertainty
OATS open-area test site
RRT round-robin test
SAC semi-anechoic chamber
SCU standards compliance uncertainty

Page 57
8 Radiated emission measurements
Replace the existing title and text of Clause 8 by the following:
8 Radiated emission measurements using a SAC or an OATS in the frequency
range of 30 MHz to 1 000 MHz
8.1 General
8.1.1 Objective
This clause provides information and guidance for the determination of uncertainties
associated with measurement equipment and the measurement method used for radiated

emission measurements in the frequency range of 30 MHz to 1 000 MHz in a SAC or on an
OATS. Furthermore, a rationale is provided for the various uncertainty aspects described in
several parts of CISPR 16 that are related to the radiated emission measurement method (see
Clause 7 of CISPR 16-2-3).
In CISPR 16-4-2, the uncertainty considerations for SAC/OATS-based radiated emission
measurements are limited to measurement instrumentation uncertainties (MIU). This part
addresses all uncertainties that are relevant for compliance testing, i.e. the standards
compliance uncertainty (SCU), which also includes the MIU.
The rationale for the methods of uncertainty estimation provided in this Clause 8 is intended
to serve as background information for the parts of CISPR 16 that are related to the
SAC/OATS-based emission measurement method. This background information may be used
by the CISPR subcommittees to improve the existing standards as far as uncertainties are
concerned. In addition, this clause provides information for those who apply the radiated
emission measurement method and who have to establish their own uncertainty estimates.

– 4 – TR CISPR 16-4-1 Amend. 2 © IEC:2007(E)

8.1.2 Introduction
Clause 8 provides information on the uncertainties associated with the SAC/OATS-based

radiated emission measurement method as described in CISPR 16-2-3. The uncertainty

estimates for the SAC/OATS radiated emission measurement method described in

CISPR 16-4-2, or for example in LAB 34 [11], address only some of the uncertainty
components present in actual compliance tests performed in accordance with CISPR 16-2-3.

Uncertainty estimates in the aforementioned documents account only for the measurement

instrumentation uncertainties (MIUs), whereas uncertainties due to the set-up of the EUT

including its cables, and due to the measurement procedure itself, are not taken into account.

In this clause, all uncertainty sources that are relevant for the measurement uncertainty of the

compliance test, termed as the standards compliance uncertainty (SCU), are considered. One

basic assumption for these SCU estimations is that the EUT does not change. In other words,
the uncertainty of the SAC/OATS radiated emission measurement method is considered
based on using the same EUT as measured by different test laboratories. The laboratories will
use different measurement instrumentation, a different test site, different measurement
procedures, and different operators. Often the laboratories may also apply different
measurement set-ups or different EUT operating modes. The latter EUT-related sources of
uncertainty may become significant, and can contribute to poor reproducibility.
The uncertainty estimation described in this clause is done in accordance with the basic
considerations on uncertainties in emission measurements given in Clause 4.
8.2 Uncertainties related to the SAC/OATS radiated emission measurement method
This subclause describes the preparation of the uncertainty estimates for the SAC/OATS-
based radiated emission measurement method described in Clause 7 of CISPR 16-2-3. For
reference, a schematic overview of the radiated emission measurement method is given in
Figure 8-1. This figure shows an EUT set up on a positioning table in a SAC. The receive
antenna measures the sum of the direct and reflected emission from the EUT.

Receive antenna
mast
SAC
Receive antenna
Direct
Table top
ray
EUT
EUT
cable
Reflected
ray
Receive antenna
cable
EUT
table
Ground plane
Receiver
IEC  506/07
Figure 8-1 – Schematic of a radiated emission measurement set-up in a SAC

TR CISPR 16-4-1 Amend. 2 © IEC:2007(E) – 5 –

8.2.1 The measurand
Previously, the measurand for the SAC/OATS-based radiated emission measurement method

in CISPR 16-2-3 was only incompletely defined. In Clause 4 of CISPR 16-1-4, which covers

the frequency range 9 kHz to 18 GHz, a reference antenna (balanced dipole) was specified in

the range 30 MHz to 300 MHz. For convenience, this measurand was called the reference
electric field strength (E-field), i.e. the E-field measured by the CISPR reference antenna. In

the frequency range 300 MHz to 1 000 MHz, a reference antenna was not defined, and the

measurand is the electric field strength.

Recently work was begun in CISPR/A to implement E-field as the quantity to be measured

over the frequency range of 30 MHz to 1 000 MHz, with an amendment under development at

the time of writing.
In this subclause it is assumed that the quantity to be measured is the E-field. However, this
is not a complete description of the measurand, because as described in the ISO GUM the
measurand definition also requires statements about the influence quantities.
From a metrological viewpoint, a more appropriate description of the measurand associated
with the SAC/OATS-based radiated emission measurement, is as follows:
The quantity to be measured is the maximum field strength emitted by the EUT as a function
of horizontal and vertical polarisation and at heights between 1 m and 4 m, and at a horizontal
distance of 10 m from the EUT, over all angles in the azimuth plane. This quantity shall be
determined with the following provisions:
a) the frequency range of interest is 30 MHz to 1 000 MHz;
b) the quantity shall be expressed in terms of field strength units that correspond with the
units used to express the limit levels for this quantity;
c) a SAC/OATS measurement site and positioning table shall be used that complies with
the applicable CISPR validation requirements;
d) a CISPR-compliant EMI receiver shall be used;
e) the application of alternative measurement distances, such as 3 m or 30 m rather than
the nominal distance of 10 m (see 8.2.3.3a), is considered to be an alternative
measurement method; correlation factors shall be used to translate results obtained at
these measurement distances to 10 m results (see 8.2.3.3a for the consequences in
terms of uncertainties);
f) the measurement distance is the horizontal projection onto the ground plane of the
distance between the boundary of the EUT and the antenna reference point;
g) the EUT is configured and operated in accordance with the CISPR specifications;

h) free-space-antenna factors shall be used.
The measurand E is derived from the maximum voltage reading V by using the free-space
r
antenna factor AF:
IQ
E =V + L + F + C (8-1)
r c A
∑ i
i
where
E
is the field strength in dB(μV/m) as described in the measurand description;
V
is the maximum voltage reading in dB(μV) using the procedure as described
r
in the measurand description;
L is the loss in dB of the measuring cable between antenna and receiver;
c
– 6 – TR CISPR 16-4-1 Amend. 2 © IEC:2007(E)

-1
)
F
A is the free-space antenna factor of the receive antenna in dB(m );

IQ IQ
C is the sum of the correction factors C that may be applicable for the
∑ i i
i
various influence quantities as described in 8.2.3.

8.2.2 Uncertainty sources
This subclause summarises the sources of uncertainty associated with the SAC/OATS-based

measurement method. From Equation (8-1) it can be seen that the uncertainty is determined

by the uncertainty of the measured voltage, the uncertainty of the cable loss, and the

uncertainty of the antenna factor.

The uncertainty of the measured voltage is determined by the uncertainties induced by the
EUT, the set-up, the measurement procedure, the measurement instrumentation and the
environment. Figure 8-2 gives a schematic overview of all the relevant uncertainty sources.
This fish-bone diagram indicates the categories of uncertainty sources that contribute to the
overall uncertainty of the measurand. An important set-up uncertainty source is the
reproducibility of the set-up of the EUT.

MEASUREMENT
PROCEDURE
Nominal measurement -
SET-UP
distance
EUT Receiver settings -
EUT cables -
Height scanning
influence type -
receive antenna-
of EUT
Azimuth
EUT units -
Reproducibility -
scanning EUT -
Receiver performance -
OVERALL
Climatic -
UNCERTAINTY
ambient
Test site performance -
Electromagnetic -
Receive
ambient
antenna performance -
Receive antenna cable -
Mains
connection -
Repeatability -
MEASUREMENT
INSTRUMENTATION ENVIRONMENT
IEC  507/07
Figure 8-2 – Uncertainty sources associated with the SAC/OATS radiated emission
measurement method
—————————
1)
Free-space antenna factors are used as a figure of merit for the antenna. It should be noted the field strength is
not measured in a free-space environment but over a ground plane. See 8.2.3.5 h) for further information.

TR CISPR 16-4-1 Amend. 2 © IEC:2007(E) – 7 –

8.2.3 Influence quantities
For most of the qualitative uncertainty sources given in Figure 8-2, one or more influence

quantities can be used to “translate” the uncertainty source in question. Table 8-1 shows the

relationship between the uncertainty sources and the influence quantities. If an influence

quantity cannot be identified, the original
...