IEC TR 61000-1-9:2024

IEC TR 61000-1-9 ®
Edition 1.0 2024-03
TECHNICAL
REPORT
Electromagnetic compatibility (EMC) –
Part 1-9: General – Evaluation of uncertainty for the measurement of harmonic
current emissions
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 Secretariat Tel.: +41 22 919 02 11
3, rue de Varembé info@iec.ch
CH-1211 Geneva 20 www.iec.ch
Switzerland
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 corrigendum or an amendment might have been published.

IEC publications search - webstore.iec.ch/advsearchform IEC Products & Services Portal - products.iec.ch
The advanced search enables to find IEC publications by a Discover our powerful search engine and read freely all the
variety of criteria (reference number, text, technical publications previews, graphical symbols and the glossary.
committee, …). It also gives information on projects, replaced With a subscription you will always have access to up to date
and withdrawn publications. content tailored to your needs.

IEC Just Published - webstore.iec.ch/justpublished
Electropedia - www.electropedia.org
Stay up to date on all new IEC publications. Just Published
The world's leading online dictionary on electrotechnology,
details all new publications released. Available online and once
containing more than 22 500 terminological entries in English
a month by email.
and French, with equivalent terms in 25 additional languages.

Also known as the International Electrotechnical Vocabulary
IEC Customer Service Centre - webstore.iec.ch/csc
(IEV) online.
If you wish to give us your feedback on this publication or need

further assistance, please contact the Customer Service
Centre: sales@iec.ch.
IEC TR 61000-1-9 ®
Edition 1.0 2024-03
TECHNICAL
REPORT
Electromagnetic compatibility (EMC) –

Part 1-9: General – Evaluation of uncertainty for the measurement of harmonic

current emissions
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 33.100.10; 33.100.01 ISBN 978-2-8322-8282-3

– 2 – IEC TR 61000-1-9:2024 © IEC 2024
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 7
4 Uncertainty evaluation for harmonic emissions tests in IEC 61000-3-2 and
IEC 61000-3-12 . 7
4.1 Methodology . 7
4.2 Measurement model. 8
4.3 Uncertainty components for worst-case scenario . 9
4.3.1 Method . 9
4.3.2 Current measurement equipment . 9
4.3.3 Input impedance of the current measurement equipment . 9
4.3.4 Test voltage RMS value . 10
4.3.5 Harmonic distortion of the test voltage . 10
4.3.6 Loading effect of the voltmeter. 11
4.4 Uncertainty budget for Class A harmonic 5 . 11
5 Uncertainty budget for typical measurement data . 12
5.1 General . 12
5.2 Current measurement equipment . 12
5.3 Input impedance of the measurement equipment . 13
5.4 Test voltage RMS value . 13
5.5 Harmonic distortion of the test voltage . 14
5.6 Loading effect of the voltmeter . 14
6 Measurement uncertainty supporting conformity decisions . 15
Annex A (informative) Worst-case uncertainty budgets for various EUT classes of
tests and selected harmonics . 16
Bibliography . 23

Figure 1 – Measurement circuit for single-phase equipment . 8

Table 1 – Worst-case uncertainty budget for Class A, Harmonic 5 . 11
Table A.1 – Worst-case uncertainty budget for Class A, Harmonic 5 . 16
Table A.2 – Worst-case uncertainty budget for Class A, Harmonic 6 . 17
Table A.3 – Worst-case uncertainty budget for Class A, Harmonic15 . 17
Table A.4 – Worst-case uncertainty budget for Class A, Harmonic 40 . 18
Table A.5 – Worst-case uncertainty budget for Class C, Harmonic 3 . 18
Table A.6 – Worst-case uncertainty budget for Class C, Harmonic 5 . 19
Table A.7 – Worst-case uncertainty budget for Class C, Harmonic 11 . 20
Table A.8 – Worst-case uncertainty budget for Class D, Harmonic 3 . 21
Table A.9 – Worst-case uncertainty budget for Class D, Harmonic 11 . 22

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ELECTROMAGNETIC COMPATIBILITY (EMC) –

Part 1-9: General – Evaluation of uncertainty for
the measurement of harmonic current emissions

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 international
co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,
Publicly Available Specifications (PAS) and Guides (hereafter referred to as "IEC Publication(s)"). Their
preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
may participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for
Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence between
any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
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) IEC draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). IEC takes no position concerning the evidence, validity or applicability of any claimed patent rights in
respect thereof. As of the date of publication of this document, IEC had not received notice of (a) patent(s), which
may be required to implement this document. However, implementers are cautioned that this may not represent
the latest information, which may be obtained from the patent database available at https://patents.iec.ch. IEC
shall not be held responsible for identifying any or all such patent rights.
IEC TR 61000-1-9 has been prepared by subcommittee 77A: EMC - Low frequency phenomena,
of IEC technical committee 77: Electromagnetic compatibility. It is a Technical Report.
The text of this Technical Report is based on the following documents:
Draft Report on voting
77A/1194/DTR 77A/1204/RVDTR
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 Technical Report is English.

– 4 – IEC TR 61000-1-9:2024 © IEC 2024
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 61000 series, published under the general title Electromagnetic
compatibility (EMC), can be found on the IEC website.
This document contains attached files in the form of a spreadsheet. These files are intended to
be used as a complement and do not form an integral part of the document.
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, or
• revised.
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 levels
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
or 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 purpose of this document is to help testing laboratories that operate in accordance with
ISO/IEC 17025 to evaluate measurement uncertainty of harmonic current emission tests for
IEC 61000-3-2 and IEC 61000-3-12.
The document contains practical formulae that enable uncertainty calculations in accordance
with ISO/IEC Guide 98-3 (GUM).
The tables in this document provide examples relating to a worst-case scenario when the
measurement equipment introduces maximum permissible errors, as specified in IEC 61000-4-7
and IEC 61000-3-2 and the combination of fundamental and harmonic currents drawn by the
equipment under test (EUT) is least favourable.
Furthermore the detailed formulae, linking the uncertainty contribution with the corresponding
source of uncertainty, allow the user of the document to calculate measurement uncertainties
based on their own measurement data. Typically, these uncertainties would be significantly
lower than the worst-case uncertainties.

– 6 – IEC TR 61000-1-9:2024 © IEC 2024
ELECTROMAGNETIC COMPATIBILITY (EMC) –

Part 1-9: General – Evaluation of uncertainty for
the measurement of harmonic current emissions

1 Scope
This document provides examples for the evaluation of measurement uncertainty of harmonic
emission tests performed using IEC 61000-3-2 and IEC 61000-3-12, and their application to the
relevant conformity decisions. It also contains practical formulae to enable calculations in
accordance with ISO/IEC Guide 98-3 (GUM).
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 61000-3-2:2018, Electromagnetic compatibility (EMC) – Part 3-2: Limits – Limits for
harmonic current emissions (equipment input current ≤16 A per phase)
IEC 61000-3-2:2018/AMD1:2020
IEC 61000-3-12, Electromagnetic Compatibility (EMC) – Part 3-12: Limits – Limits for harmonic
currents produced by equipment connected to public low-voltage systems with input
current >16 A and ≤75 A per phase
IEC 61000-4-7:2002, Electromagnetic compatibility (EMC) – Part 4-7: Testing and
measurement techniques – General guide on harmonics and interharmonics measurements and
instrumentation, for power supply systems and equipment connected thereto
IEC 61000-4-7:2002/AMD1:2008
IEC GUIDE 115, Application of uncertainty of measurement to conformity assessment activities
in the electrotechnical sector
ISO/IEC 17025:2017, General requirements for the competence of testing and calibration
laboratories
ISO/IEC GUIDE 98-3, Uncertainty of measurement – Part 3: Guide to the expression of
uncertainty in measurement (GUM:1995)
ISO/IEC GUIDE 99, International vocabulary of metrology – Basic and general concepts and
associated terms (VIM)
JCGM 106:2012, Evaluation of measurement data – The role of measurement uncertainty in
conformity assessment
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 61000-3-2,
IEC 61000-3-12, IEC 61000-4-7, IEC GUIDE 115, ISO/IEC 17025, ISO/IEC GUIDE 98-3,
ISO/IEC GUIDE 99 and JCGM 106, 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
4 Uncertainty evaluation for harmonic emissions tests in IEC 61000-3-2 and
IEC 61000-3-12
4.1 Methodology
Testing laboratories that operate in accordance with ISO/IEC 17025 are required to evaluate
measurement uncertainty (ISO/IEC 17025:2017, 7.6.3). Other laboratories could, likewise, do
so.
This document applies ISO/IEC Guide 98-3 (GUM) to calculate the measurement uncertainty
for the tests performed as specified in IEC 61000-3-2 and IEC 61000-3-12.
In 4.3, the uncertainty calculation is made for the worst-case scenario, when the following
conditions are met:
– measurement equipment introduces maximum permissible errors, as specified in
IEC 61000-4-7 and IEC 61000-3-2;
– the combination of fundamental and harmonic currents drawn by the equipment under test
(EUT) is the least favourable. It is based on an EUT that reacts linearly to every external
influence quantity. While not every EUT item exhibits such behaviour, the use of a linear
model provides a meaningful uncertainty estimate for the purpose of conformity assessment.
When the EUT is known to be non-linear, for example, when its harmonic emission currents
depend on the harmonic composition of the test voltage, further evaluation can be required
if accurate uncertainty assessment is sought.
Examples for typical uncertainties are given in Clause 5.
The calculated worst-case uncertainty values are expressed as a percentage of permissible
harmonic current limit for a particular class of the EUT and harmonic number.
The detailed formulae, linking the uncertainty contribution with the corresponding source of
uncertainty, allow the user of the document to calculate measurement uncertainties for the
relevant tests. Typically, these uncertainties would be significantly lower than the worst-case
uncertainties.
To calculate measurement uncertainty in accordance with ISO/IEC Guide 98-3, the following
steps are performed:
a) a measurement model is established, where the measurement is expressed in terms of
formulae linking the measurand with each input quantity (see 4.2);
b) all uncertainty components are listed, their values characterized, and their effect on the
measurement calculated numerically (see 4.3);
c) the combined standard uncertainty and the expanded uncertainty values are calculated and
tabulated in the uncertainty budget (see 4.4).

– 8 – IEC TR 61000-1-9:2024 © IEC 2024
4.2 Measurement model
An equipment setup shown in IEC 61000-3-2:2018, Figure A.1, is considered. The setup is used
to measure current harmonics of a Class A appliance, see IEC 61000-3-2:2018 and
IEC 61000-3-2:2018/AMD1:2020, 5.1.

Key
S power supply source Z input impedance of measurement equipment
M
M measurement equipment Z internal impedance of the supply source
S
EUT equipment under test I harmonic component of order h of the line current
h
U test voltage G open-loop voltage of the supply source

[SOURCE: IEC 61000-3-2:2018, Figure A.1]
Figure 1 – Measurement circuit for single-phase equipment
The measured harmonic current can be expressed as:
YI= (11+δδ)− 1+δ 1+δ (1−δ ) . (1)
hM ( ZU)( )( U ) V
M RMS THD
where:
Y is the measured value of harmonic current of a particular harmonic frequency,
corrected for all known systematic effects,
is the true value of harmonic current,
I
h
δ is the error of the current measurement equipment such as a power analyser,
M
δ is the error due to the input impedance of current measurement equipment,
Z
M
δ is the error due to the RMS value of the test voltage,
U
RMS
δ is the error due to the harmonic distortion in the test voltage, and
U
THD
δ is the loading effect of the voltmeter (connected in parallel to the EUT but not shown
V
in Figure 1).
The positive or negative sign indicates whether the measured value Y will increase or decrease
when a positive value of a particular error component is present. The sign has no bearing on
the uncertainty as the uncertainty components are root sum squared to obtain the standard
uncertainty, see Formula (8).
4.3 Uncertainty components for worst-case scenario
4.3.1 Method
As an example, to calculate worst-case uncertainties, a Class A EUT drawing a rated RMS
th
current of 16 A and a harmonic current equal to the maximum permissible current of the 5
harmonic (1,14 A) is considered. The EUT and the measurement equipment are connected as
shown in Figure 1.
ISO/IEC Guide 98-3 (GUM) is applied to calculate standard uncertainties contributed by each
error component in 4.2. Maximum permissible errors, as specified in IEC 61000-4-7 and
IEC 61000-3-2, are used for the calculation of each uncertainty component.
th
In this example, the uncertainties are exp
...