CISPR TR 16-4-4:2003

TECHNICAL CISPR
REPORT 16-4-4
First edition
2003-11
INTERNATIONAL SPECIAL COMMITTEE ON RADIO INTERFERENCE
Specification for radio disturbance and immunity
measuring apparatus and methods –

Part 4-4:
Uncertainties, statistics and limit modelling –
Statistics of complaints and a model
for the calculation of limits
Reference number
CISPR 16-4-4/TR:2003(E)
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TECHNICAL CISPR
REPORT 16-4-4
First edition
2003-11
INTERNATIONAL SPECIAL COMMITTEE ON RADIO INTERFERENCE
Specification for radio disturbance and immunity
measuring apparatus and methods –

Part 4-4:
Uncertainties, statistics and limit modelling –
Statistics of complaints and a model
for the calculation of limits
© IEC 2003 ⎯ Copyright - all rights reserved
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For price, see current catalogue

– 2 – CISPR 16-4-4/TR © IEC:2003(E)

CONTENTS
FOREWORD.3

INTRODUCTION.5

TABLE RECAPITULATING CROSS-REFERENCES .7

1 Scope .8

2 Normative references.8

3 Definitions .8
4 Recommendation 2/3: Statistics of complaints and sources of interference .9
Appendix I to Recommendation 2/3: Classification of sources of interference and
other causes of complaint.10
Appendix II to Recommendation 2/3: Classification of sources of interference and
other causes of complaint.13
5 A model for the calculation of limits.18
5.1 Introduction .18
5.2 Probability of interference.18
5.3 Circumstances of interferences.20
5.4 Basic model.28
5.5 Application of the basic model .29
5.6 An alternative method used for ISM equipment.32
Annex 5.6-A Summary of proposals for determination of limits .36
5.6-A.1 Experience approach .36
5.6-A.2 User and manufacturer responsibility for avoidance of interference .36
5.6-A.3 Calculation of limits on a worst-case basis .37
5.6-A.4 Statistical evaluation approach.37

CISPR 16-4-4/TR © IEC:2003(E) – 3 –

INTERNATIONAL ELECTROTECHNICAL COMMISSION
INTERNATIONAL SPECIAL COMMITTEE ON RADIO INTERFERENCE

____________
SPECIFICATION FOR RADIO DISTURBANCE AND IMMUNITY

MEASURING APPARATUS AND METHODS –

Part 4-4: Uncertainties, statistics and limit modelling –

Statistics of complaints and a model for the calculation of limits

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
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2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
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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.

The main task of IEC technical committees is to prepare International Standards. However, a
technical committee may propose the publication of a technical report when it has collected
data of a different kind from that which is normally published as an International Standard, for
example "state of the art".
CISPR 16-4-4, which is a technical report, has been prepared by CISPR subcommittee A:
Radio interference measurements and statistical methods.
This first edition of CISPR 16-4-4, together with CISPR 16-4-1, CISPR 16-4-3 and the second
edition of CISPR 16-3, cancels and replaces the first edition of CISPR 16-3, published in
2000, and its amendment 1 (2002). It contains the relevant clauses of CISPR 16-3 without
technical changes.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
A bilingual version of this publication may be issued at a later date.

– 4 – CISPR 16-4-4/TR © IEC:2003(E)

The committee has decided that the contents of this publication will remain unchanged until

2004. At this date, the publication will be

• reconfirmed;
• withdrawn;
• replaced by a revised edition, or

• amended.
The text of this publication is based on the following documents:

Recommendation 2/2 – p/o CISPR 7B, 1975; CIS/A(CO)67 , 1992; CIS/A(CO)67A, 1993;

Report 61 – CISPR 23:1987; CISPR/A(Sec)81, 1987.

CISPR 16-4-4/TR © IEC:2003(E) – 5 –

INTRODUCTION
CISPR 16-1, CISPR 16-2, CISPR 16-3 and CISPR 16-4 have been reorganised into 14 parts,

to accommodate growth and easier maintenance. The new parts have also been renumbered.

See the list given below.
Old CISPR 16 publications New CISPR 16 publications

CISPR 16-1-1 Measuring apparatus

CISPR 16-1-2 Ancillary equipment – Conducted disturbances
Radio disturbance
and immunity
CISPR 16-1-3 Ancillary equipment – Disturbance power

CISPR 16-1
measuring
apparatus
Ancillary equipment – Radiated disturbances
CISPR 16-1-4
Antenna calibration test sites for 30 MHz to
CISPR 16-1-5
1 000 MHz
CISPR 16-2-1 Conducted disturbance measurements
Methods of
Measurement of disturbance power
CISPR 16-2-2
measurement of
CISPR 16-2
disturbances and
CISPR 16-2-3 Radiated disturbance measurements
immunity
CISPR 16-2-4
Immunity measurements
CISPR 16-3 CISPR technical reports
Uncertainties in standardised EMC tests
CISPR 16-4-1
Reports and
Measurement instrumentation uncertainty
CISPR 16-3 recommendations CISPR 16-4-2
of CISPR
Statistical considerations in the
CISPR 16-4-3
determination of EMC compliance of mass-
produced products
Statistics of complaints and a model for the
Uncertainty in EMC
CISPR 16-4 CISPR 16-4-4
calculation of limits
measurements
More specific information on the relation between the ‘old’ CISPR 16-3 and the present ‘new’
CISPR 16-4-4 is given in the table after this introduction (TABLE RECAPITULATING CROSS
REFERENCES).
Measurement instrumentation specifications are given in five new parts of CISPR 16-1, while
the methods of measurement are covered now in four new parts of CISPR 16-2. Various
reports with further information and background on CISPR and radio disturbances in general
are given in CISPR 16-3. CISPR 16-4 contains information related to uncertainties, statistics
and limit modelling.
CISPR 16-4 consists of the following parts, under the general title Specification for radio
disturbance and immunity measuring apparatus and methods - Uncertainties, statistics and
limit modelling:
• Part 4-1: Uncertainties in standardised EMC tests,
• Part 4-2: Uncertainty in EMC measurements,
• Part 4-3: Statistical considerations in the determination of EMC compliance of mass-
produced products,
• Part 4-4: Statistics of complaints and a model for the calculation of limits.
For practical reasons, standardised EMC tests are drastic simplifications of all possible EMI
scenarios that a product may encounter in practice. Consequently, in an EMC standard the
measurand, the limit, measurement instruments, set-up, measurement procedure and
measurement conditions shall be simplified but still meaningful. Meaningful means that there
is a statistical correlation between compliance of the product with a standardized EMC test
and a high probability of actual EMC of the same product during its life cycle. Part 4-4
provides statistically based methods to derive meaningful disturbance limits for the protection
of radio services.
– 6 – CISPR 16-4-4/TR © IEC:2003(E)

In general, a standardized EMC test must be developed such that reproducible results are

obtained if different parties perform the same test with the same product. However, various

uncertainty sources and influence quantities cause that the reproducibility of a standardized

EMC test is limited. Part 4-1 consists of a collection of informative reports that deal with all

relevant uncertain
...