SIST EN IEC 60704-1:2021
(Main)Household and similar electrical appliances - Test code for the determination of airborne acoustical noise - Part 1: General requirements
Household and similar electrical appliances - Test code for the determination of airborne acoustical noise - Part 1: General requirements
IEC 60704-1:2021 is available as IEC 60704-1:2021 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.
IEC 60704-1:2021 applies to electric appliances (including their accessories or components) for household and similar use, supplied from mains or from batteries.
By "similar use" is understood the use in conditions similar to those found in households, for example in inns, coffee houses, tea rooms, hotels, barber or hairdresser shops, launderettes, etc., if not otherwise specified in the IEC 60704-2 series.
This document does not apply to:
– appliances, equipment, or machines designed exclusively for industrial or professional purposes;
– appliances that are integrated parts of a building or its installations, such as equipment for air conditioning, heating and ventilating (except household fans, cooker hoods, free-standing heating appliances, dehumidifiers, air cleaners, and stand-alone water heaters), oil burners for central heating, pumps for water supply and for sewage systems;
– separate motors or generators and
– appliances exclusively for outdoor use.
For determining and verifying noise emission values declared in product specifications, see IEC 60704-3:2019.
This fourth edition cancels and replaces the third edition published in 2010. This edition constitutes a technical revision.
It includes the following significant changes with respect to the previous edition:
a) update of references (especially to ISO standards);
b) revision of requirements on climatic conditions;
c) revision of requirements on background noise level.
Elektrische Geräte für den Hausgebrauch und ähnliche Zwecke - Prüfvorschrift für die Bestimmung der Luftschallemission - Teil 1: Allgemeine Anforderungen
Appareils électrodomestiques et analogues - Code d'essai pour la détermination du bruit aérien - Partie 1: Exigences générales
IEC 60704-1:2021 est disponible sous forme de IEC 60704-1:2021 RLV qui contient la Norme internationale et sa version Redline, illustrant les modifications du contenu technique depuis l'édition précédente.
L’IEC 60704-1:2021 s’applique aux appareils électriques pour usages domestiques et analogues, y compris leurs accessoires ou composants, alimentés à partir du réseau ou par piles ou accumulateurs.
L’expression "usages analogues" s’entend des usages dans des conditions similaires à celles des foyers domestiques, par exemple dans les restaurants, cafés, salons de thé, hôtels, salons de coiffure, laveries, etc. sauf spécification contraire dans la série IEC 60704-2.
Le présent document ne s’applique pas
– aux appareils, équipements ou machines conçus exclusivement pour des usages industriels ou professionnels;
– aux appareils qui font partie intégrante d’un bâtiment ou de ses installations, tels que les équipements de climatisation, de chauffage ou de ventilation (à l’exception des ventilateurs domestiques, des hottes de cuisine et des appareils de chauffage indépendants, des déshumidificateurs, des épurateurs d’air et des chauffe-eau indépendants), aux brûleurs à mazout pour le chauffage central, aux pompes pour l’alimentation en eau et pour les systèmes d’eaux usées;
– aux moteurs ou générateurs individuels; et
– aux appareils exclusivement destinés à une utilisation à l’extérieur.
Pour déterminer et vérifier les valeurs d’émission acoustique déclarées dans les spécifications de produit, voir l’IEC 60704-3:2019.
Cette quatrième édition annule et remplace la troisième édition parue en 2010. Cette édition constitue une révision technique.
Elle inclut les modifications majeures suivantes par rapport à l’édition précédente:
a) mise à jour des références (notamment aux normes ISO);
b) révision des exigences relatives aux conditions climatiques;
c) révision des exigences relatives au niveau de bruit de fond.
Gospodinjski in podobni električni aparati - Postopek preskušanja za ugotavljanje zvočnega hrupa v zraku - 1. del: Splošne zahteve
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
01-december-2021
Nadomešča:
SIST EN 60704-1:2010
SIST EN 60704-1:2010/A11:2013
Gospodinjski in podobni električni aparati - Postopek preskušanja za ugotavljanje
zvočnega hrupa v zraku - 1. del: Splošne zahteve
Household and similar electrical appliances - Test code for the determination of airborne
acoustical noise - Part 1: General requirements
Appareils électrodomestiques et analogues - Code d'essai pour la détermination du bruit
aérien - Partie 1: Exigences générales
Ta slovenski standard je istoveten z: EN IEC 60704-1:2021
ICS:
17.140.20 Emisija hrupa naprav in Noise emitted by machines
opreme and equipment
97.030 Električni aparati za dom na Domestic electrical
splošno appliances in general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EUROPEAN STANDARD EN IEC 60704-1
NORME EUROPÉENNE
EUROPÄISCHE NORM
October 2021
ICS 13.120; 97.170 Supersedes EN 60704-1:2010 and all of its amendments
and corrigenda (if any)
English Version
Household and similar electrical appliances - Test code for the
determination of airborne acoustical noise - Part 1: General
requirements
(IEC 60704-1:2021)
Appareils électrodomestiques et analogues - Code d'essai Elektrische Geräte für den Hausgebrauch und ähnliche
pour la détermination du bruit aérien - Partie 1: Exigences Zwecke - Prüfvorschrift für die Bestimmung der
générales Luftschallemission - Teil 1: Allgemeine Anforderungen
(IEC 60704-1:2021) (IEC 60704-1:2021)
This European Standard was approved by CENELEC on 2021-04-15. CENELEC members are bound to comply with the CEN/CENELEC
Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC
Management Centre or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2021 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 60704-1:2021 E
European foreword
The text of document 59/753/FDIS, future edition 4 of IEC 60704-1, prepared by IEC/TC 59
"Performance of household and similar electrical appliances" was submitted to the IEC-CENELEC
parallel vote and approved by CENELEC as EN IEC 60704-1:2021.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2022-01-15
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) –
document have to be withdrawn
This document supersedes EN 60704-1:2010 and all of its amendments and corrigenda (if any).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national committee. A
complete listing of these bodies can be found on the CENELEC website.
Endorsement notice
The text of the International Standard IEC 60704-1:2021 was approved by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standards
indicated:
IEC 60038:2009 NOTE Harmonized as EN 60038:2011 (modified)
ISO 3741:2010 NOTE Harmonized as EN ISO 3741:2010 (not modified)
ISO 3745:2012 NOTE Harmonized as EN ISO 3745:2012 (not modified)
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
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.
NOTE 1 Where an International Publication has been modified by common modifications, indicated by (mod),
the relevant EN/HD applies.
NOTE 2 Up-to-date information on the latest versions of the European Standards listed in this annex is available
here: www.cenelec.eu.
Publication Year Title EN/HD Year
IEC 60704-2 series Household and similar electrical EN IEC 60704-2 series
appliances - Test code for the
determination of airborne acoustical
noise
IEC 60704-3 (mod) 2019 Household and similar electrical EN 60704-3 2019
appliances - Test code for the
determination of airborne acoustical
noise - Part 3: Procedure for
determining and verifying declared
noise emission values
IEC 61260-1 2014 Electroacoustics - Octave-band and EN 61260-1 2014
fractional-octave-band filters - Part 1:
Specifications
IEC 61672-1 2013 Electroacoustics - Sound level meters - EN 61672-1 2013
Part 1: Specifications
ISO 3743-1 2010 Acoustics - Determination of sound EN ISO 3743-1 2010
power levels and sound energy levels
of noise sources using sound pressure -
Engineering methods for small movable
sources in reverberant fields - Part 1:
Comparison method for a hard-walled
test room
ISO 3743-2 2018 Acoustics - Determination of sound EN ISO 3743-2 2019
power levels of noise sources using
sound pressure - Engineering methods
for small, movable sources in
reverberant fields - Part 2: Methods for
special reverberation test rooms
ISO 3744 2010 Acoustics - Determination of sound EN ISO 3744 2010
power levels and sound energy levels
of noise sources using sound pressure -
Engineering methods for an essentially
free field over a reflecting plane
Publication Year Title EN/HD Year
ISO 9614-1 1993 Acoustics - Determination of sound EN ISO 9614-1 2009
power levels of noise sources using
sound intensity - Part 1: Measurement
at discrete points
ISO 9614-2 1996 Acoustics - Determination of sound EN ISO 9614-2 1996
power levels of noise sources using
sound intensity - Part 2: Measurement
by scanning
ISO 9614-3 2002 Acoustics - Determination of sound EN ISO 9614-3 2009
power levels of noise sources using
sound intensity - Part 3: Precision
method for measurement by scanning
ISO 6926 2016 Acoustics - Requirements for the EN ISO 6926 2016
performance and calibration of
reference sound sources used for the
determination of sound power levels
ISO 12001 1996 Acoustics - Noise emitted by machinery EN ISO 12001 2009
and equipment - Rules for the drafting
and presentation of a noise test code
IEC 60704-1 ®
Edition 4.0 2021-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Household and similar electrical appliances – Test code for the determination
of airborne acoustical noise –
Part 1: General requirements
Appareils électrodomestiques et analogues – Code d’essai pour la
détermination du bruit aérien –
Partie 1: Exigences générales
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 13.120; 97.170 ISBN 978-2-8322-9515-1
– 2 – IEC 60704-1:2021 © IEC 2021
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 8
4 Measurement methods and acoustical environments . 9
4.1 General . 9
4.2 Direct method . 9
4.3 Comparison method . 10
4.4 Acoustical environments . 10
4.4.1 General requirements and criterion for adequacy of the test
environment . 10
4.4.2 Criterion for background noise level . 11
4.4.3 Environmental conditions . 11
4.5 Measurement uncertainties . 11
4.5.1 General . 11
4.5.2 Standard deviations on repeatability and reproducibility and standard
deviations related to declaration and verification . 11
5 Instrumentation . 12
5.1 Instrumentation for measuring acoustical data . 12
5.2 Instrumentation for measuring climatic conditions . 12
5.3 Instrumentation for measuring operating conditions . 12
6 Operation and location of appliances under test . 13
6.1 Equipping and pre-conditioning of appliances . 13
6.2 Supply of electric energy and of water or gas . 13
6.3 Climatic conditions . 14
6.4 Loading and operating of appliances during tests . 14
6.5 Location and mounting of appliances . 15
7 Measurement of sound pressure levels . 17
7.1 Microphone array, measurement surface and RSS location for essentially
free field conditions over reflecting plane(s) . 17
7.2 Microphone array and RSS location in hard-walled test rooms . 25
7.3 Microphone array and RSS location in special reverberation test rooms . 25
7.4 Measurements . 25
8 Calculation of sound pressure and sound power levels . 26
8.1 General . 26
8.2 Corrections for background noise levels . 26
8.3 Corrections for the test environment . 27
8.4 Calculation of sound pressure level averaged over the microphone positions . 27
8.5 Calculation of sound power levels with the comparison method . 27
8.6 Calculation of sound power levels in free field conditions over a reflecting
plane . 28
8.7 Calculation of A-weighted sound power level with the direct method in
special reverberation test rooms . 28
9 Information to be recorded . 29
9.1 General data . 29
IEC 60704-1:2021 © IEC 2021 – 3 –
9.2 Description of appliance under test . 29
9.3 Measurement method . 29
9.4 Acoustical test environment . 29
9.5 Instrumentation . 30
9.6 Equipment and pre-conditioning of appliance under test . 30
9.7 Electric supply, water supply, etc. . 30
9.8 Climatic conditions . 30
9.9 Operation of the appliance under test . 30
9.10 Location and mounting of the appliance under test. 30
9.11 Microphone array . 31
9.12 Measurement data . 31
9.13 Calculated sound pressure and sound power levels . 31
9.14 Reporting . 31
10 Information to be reported . 32
10.1 General data . 32
10.2 Appliance under test . 32
10.3 Test conditions for the appliance . 32
10.4 Acoustical data . 33
Annex A (normative) Standard test table . 34
Annex B (normative) Test enclosure . 35
Annex C (informative) Guidelines for the design of simple test rooms with essentially
free field conditions. 36
Bibliography . 37
Figure 1 – Measurement surface – parallelepiped – with key microphone positions, for
floor free-standing appliances . 18
Figure 2 – Measurement surface – parallelepiped – with key microphone positions, for
floor standing appliances placed against a wall . 19
Figure 3 – Measurement surface – parallelepiped – with key microphone positions, for
high floor-standing appliances placed against a wall . 20
Figure 4 – Measurement surface – hemisphere – with key microphone positions, for
hand-held, table type and floor-treatment appliances . 21
Figure 5 – Measurement surface – quarter-sphere – with key microphone positions, for
small floor-standing appliances placed against a wall . 22
Figure 6 – Measurement surface – parallelepiped – with five or nine microphone
positions for stand-type appliances . 24
Figure A.1 – Example of standard test table . 34
Figure B.1 – Test enclosure . 35
Table 1 – Standard deviations of sound power levels . 12
Table 2 – Standard deviations for declaration and verification . 12
– 4 – IEC 60704-1:2021 © IEC 2021
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
HOUSEHOLD AND SIMILAR ELECTRICAL APPLIANCES –
TEST CODE FOR THE DETERMINATION
OF AIRBORNE ACOUSTICAL NOISE –
Part 1: General requirements
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) 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 60704-1 has been prepared by IEC technical committee 59:
Performance of household and similar electrical appliances.
This fourth edition cancels and replaces the third edition published in 2010. This edition
constitutes a technical revision.
It includes the following significant changes with respect to the previous edition:
a) update of references (especially to ISO standards);
b) revision of requirements on climatic conditions;
c) revision of requirements on background noise level.
IEC 60704-1:2021 © IEC 2021 – 5 –
The text of this International Standard is based on the following documents:
FDIS Report on voting
59/753/FDIS 59/762/RVD
Full information on the voting for the approval of this International Standard can be found in
the report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all the parts in the IEC 60704 series, under the general title Household and similar
electrical appliances – Test code for the determination of airborne acoustical noise, can be
found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
– 6 – IEC 60704-1:2021 © IEC 2021
INTRODUCTION
Although the noise emitted by household appliances does not generally present a hazard to
the hearing of the operator and other exposed persons, the need for standardization
procedures for the determination of the noise emitted has been recognized for a long time.
Such procedures should be specified, not only for special types of appliances, but also the
principles should be applicable to the majority of appliances in general use.
Generally, the determination of noise levels is only part of a comprehensive testing procedure
covering many aspects of the properties and performances of the appliance. It is therefore
important that the requirements for noise measurements (such as test environment,
instrumentation, and amount of labour involved) be kept at a modest level.
The results of noise measurements are used for many purposes, for example for noise
declaration, as well as for comparing the noise emitted by a specific appliance to the noise
emitted by other appliances of the same family. In other cases, the results are taken as a
basis for engineering action in the development stages of new pieces of equipment, or in
deciding on means for sound insulation. For all purposes, it is important to specify procedures
with known accuracy so that the results of measurements taken by different laboratories can
be compared.
These conditions have, as far as possible, been taken into account in the preparation of this
test code. The acoustic measuring methods are based on those described in
ISO 3743‑1:2010, ISO 3743-2:2018 and ISO 3744:2010.
The adoption of these methods permits the use of hemi-anechoic rooms, special reverberation
test rooms and hard-walled test rooms. The result of the measurements is the sound power
level of the appliance. Within the measuring uncertainty specific to these methods, the results
from the determination under free field conditions over a reflecting plane are equal to those
obtained in reverberant fields.
The use of intensity methods as described in ISO 9614-1:1993, ISO 9614-2:1996, and
ISO 9614-3:2002 is applicable under special conditions, which are described in specific parts
of the IEC 60704-2 series.
This test code is concerned with airborne noise only. In some cases, structure-borne noise,
for example transmitted to the adjoining room, can be of importance.
IEC 60704-1:2021 © IEC 2021 – 7 –
HOUSEHOLD AND SIMILAR ELECTRICAL APPLIANCES –
TEST CODE FOR THE DETERMINATION
OF AIRBORNE ACOUSTICAL NOISE –
Part 1: General requirements
1 Scope
This part of IEC 60704 applies to electric appliances (including their accessories or
components) for household and similar use, supplied from mains or from batteries.
By "similar use" is understood the use in conditions similar to those found in households, for
example in inns, coffee houses, tea rooms, hotels, barber or hairdresser shops, launderettes,
etc., if not otherwise specified in the IEC 60704-2 series.
This document does not apply to
– appliances, equipment, or machines designed exclusively for industrial or professional
purposes;
– appliances that are integrated parts of a building or its installations, such as equipment for
air conditioning, heating and ventilating (except household fans, cooker hoods, free-
standing heating appliances, dehumidifiers, air cleaners, and stand-alone water heaters),
oil burners for central heating, pumps for water supply and for sewage systems;
– separate motors or generators and
– appliances exclusively for outdoor use.
For determining and verifying noise emission values declared in product specifications, see
IEC 60704-3:2019.
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 60704-2 (all parts), Household and similar electrical appliances – Test code for the
determination of airborne acoustical noise
IEC 60704-3:2019, Household and similar electrical appliances – Test code for the
determination of airborne acoustical noise – Part 3: Procedure for determining and verifying
declared noise emission values
IEC 61260-1:2014, Electroacoustics – Octave-band and fractional-octave-band filters – Part 1:
Specifications
IEC 61672-1:2013, Electroacoustics – Sound level meters – Part 1: Specifications
ISO 3743-1:2010, Acoustics – Determination of sound power levels of noise sources –
Engineering methods for small, movable sources in reverberant fields – Part 1: Comparison
method for hard-walled test rooms
– 8 – IEC 60704-1:2021 © IEC 2021
ISO 3743-2:2018, Acoustics – Determination of sound power levels of noise sources using
sound pressure – Engineering methods for small, movable sources in reverberant fields –
Part 2: Methods for special reverberation test rooms
ISO 3744:2010, Acoustics – Determination of sound power levels of noise sources using
sound pressure – Engineering method in an essentially free field over a reflecting plane
ISO 9614-1:1993, Acoustics – Determination of sound power levels of noise sources using
sound intensity – Part 1: Measurement at discrete points
ISO 9614-2:1996, Acoustics – Determination of sound power levels of noise sources using
sound intensity – Part 2: Measurement by scanning
ISO 9614-3:2002, Acoustics – Determination of sound power levels of noise sources using
sound intensity – Part 3: Precision method for measurement by scanning
ISO 6926:2016, Acoustics – Requirements for the performance and calibration of reference
sound sources used for the determination of sound power levels
ISO 12001:1996, Acoustics – Noise emitted by machinery and equipment – Rules for the
drafting and presentation of a noise test code
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply. Terms and
definitions pertinent to the determination of sound power levels can be found in ISO 3743-
1:2010, ISO 3743-2:2018 and ISO 3744:2010.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1
measurement time interval
portion or a multiple of an operational period or operational cycle for which the sound power
levels are determined
3.2
operational period
interval of time during which a specified process is accomplished by the appliance under test
(for example, washing or rinsing or drying for a dishwasher)
3.3
operational cycle
specific sequence of operational periods occurring while the appliance under test performs a
complete work cycle
Note 1 to entry: During the operational cycle, each operational period is associated with a specific process that
can occur only once, or can be repeated (for example, washing and rinsing and drying for a dishwasher).
3.4
time history
continuous recording of the sound pressure level (for a distinct microphone position) as a
function of time, which is obtained during one or more operational periods of an operational
cycle
IEC 60704-1:2021 © IEC 2021 – 9 –
3.5
reference box
hypothetical right parallelepiped terminating on the reflecting plane(s) on which the noise
source under test is located, that just encloses the source including all the significant sound
radiating components and any test table on which the source is mounted
[SOURCE: ISO 3744:2010, 3.10, modified – The note has been omitted.]
3.6
test enclosure
enclosure used for simulating the typical acoustic built-in or/and mounting conditions
4 Measurement methods and acoustical environments
4.1 General
This document is concerned with objective methods of engineering accuracy grade 2 in
accordance with ISO 12001:1996 for determining sound power levels L , expressed in
W
decibels (dB), with reference to a sound power of one picowatt (1 pW), of airborne acoustical
noise within the specified frequency range of interest (generally including the octave-bands
with centre frequencies from 125 Hz to 8 000 Hz), and for prescribed operating conditions of
the appliance to be measured.
Methods for determining sound power levels with precision accuracy grade 1 in accordance
with ISO 12001:1996, as specified for example in ISO 3741 and ISO 3745, are not included in
this document. They may, however, be applied if the appropriate test environment and
instrumentation are available.
NOTE 1 The noise values obtained under the described conditions of this document will not necessarily
correspond to the noise experienced under the operational conditions of practical use.
NOTE 2 For quality control during production etc., simplified methods can be appropriate. For noise reduction
purposes, other measurement methods employing, for example, narrow-band analysis or intensity techniques
usually have to be applied. These methods are not covered by this document.
The total noise emitted by machinery or equipment and radiated in all directions to the space
surrounding the machine can be characterized by the sound power of the machine. Within the
accuracy range of this document, the sound power of a machine is basically independent of
the environment in which the machine is installed
Therefore, the concept of sound power level has been chosen for expressing the noise
emission of appliances for household and similar purposes.
The preferred noise emission quantity is the A-weighted sound power level, L , in dB
WA
(re 1 pW).
According to this document, two principal methods exist, the direct method and the
comparison method, as described in 4.2 and 4.3. These two methods can be used
alternatively.
Different types of environments, as described in 4.4, may be used. A part of the IEC 60704-2
series may, if necessary, exclude one or several combinations among those available.
4.2 Direct method
The direct method can be used only for measurements in qualified test environments in
accordance with ISO 3744:2010 for free field conditions over reflecting plane(s), and in
accordance with ISO 3743-2:2018 for special reverberation test rooms.
– 10 – IEC 60704-1:2021 © IEC 2021
With this method, the sound power level is determined
– in free field conditions over reflecting plane(s), from time-averaged sound pressure levels
(on a mean-square basis) over the measurement surface and from the area of the
measurement surface, S, or
– in reverberation and special reverberation test rooms, from averaged sound pressure
levels, and from the reverberation time and the volume of the test room.
If for a measurement in a free field, reverberation or special reverberation room is not
possible because the appliance cannot be placed or operated in such an environment, the
intensity method in accordance with ISO 9614-1:1993, ISO 9614-2:1996, and ISO 9614-
3:2002 shall be applied. For the intensity method, the standard deviations given in the parts of
the IEC 60704-2 series and IEC 60704-3:2019 are not applicable unless stated explicitly.
These methods yield results expressed in A-weighted sound power levels (and in octave- or
1/3 octave-band sound power levels, if required) that are calculated directly from measured
sound pressure levels.
NOTE This method can also be used in conjunction with more precise methods, such as those given in ISO 3741
and ISO 3745.
4.3 Comparison method
The comparison method for measurement is explicitly described in ISO 3743-1:2010 and in
ISO 3743-2:2018.
NOTE The term "comparison method" is not explicitly given in ISO 3744:2010, but when applying the "absolute
comparison test" for the determination of the environmental correction given in A.3 of ISO 3744:2010, by using a
reference sound source, the procedure is, in fact, a comparison method.
With this method, the sound power level is determined by comparing the averaged values (on
a mean-square basis) of the sound pressure levels produced by the source in the test room to
the averaged values of the sound pressure levels produced in the same room by a calibrated
reference sound source (RSS) of known sound power output, complying with the requirements
of ISO 6926:2016. The difference in sound pressure levels is equal to the difference in sound
power levels when conditions are the same for both sets of measurements.
This method yields results expressed in octave- or 1/3 octave-band sound power levels, and
the A-weighted sound power level is calculated from the octave- or 1/3 octave-band sound
power levels.
To check whether there is a systematic difference between results obtained in different
environments, the use of the comparison method is recommended.
4.4 Acoustical environments
4.4.1 General requirements and criterion for adequacy of the test environment
They are given in the following clauses:
– Clause 4 of ISO 3743-1:2010 for hard-walled test rooms;
– Clause 5 of ISO 3743-2:2018 for special reverberation test rooms and
– Clause 4 of ISO 3744:2010 for free-field conditions over a reflecting plane.
A classification of different types of noise is given in ISO 12001:1996. The method specified
in ISO 3744:2010 is suitable for measurements of all types of noise emitted by household
appliances. The methods specified in ISO 3743-1:2010 and ISO 3743-2:2018 are suitable for
all types of noise, except for sources of impulsive noise consisting of short-duration noise
bursts. This will be taken into account in the preparation of parts of the IEC 60704-2 series.
IEC 60704-1:2021 © IEC 2021 – 11 –
The method specified in ISO 3744:2010 is applicable to noise sources of any size. Limitations
for the size of the source are given in 4.2 of ISO 3743-1:2010 and in Clause 5 of
ISO 3743-2:2018. This will be taken into account in the preparation of parts of the
IEC 60704-2 series.
NOTE For free-field conditions over a reflecting plane, the absolute comparison test for the qualification of the
environment, described in Clause A.2 of ISO 3744:2010, is preferred.
Guidelines for the design of simple test rooms with free-field conditions are given in Annex C.
Guidelines for the design of a suitable special reverberation test room are given in
ISO 3743-2:2018, Annex A.
4.4.2 Criterion for background noise level
Requirements for the background noise level are given in 4.5 of ISO 3743-1:2010, in 6.5 of
ISO 3743-2:2018 and in 4.2 of ISO 3744:2010. Averaged over the microphone positions, the
background noise level shall be at least 6 dB below, and preferably more than 15 dB below,
the sound pressure level to be measured.
NOTE If the difference between the sound pressure levels of the background noise and the appliance noise is
less than 6 dB, see 8.2.
4.4.3 Environmental conditions
Environmental conditions having an adverse effect on the microphone used for the
measurements (for example, strong electric or magnetic fields, wind, impingement of air
discharge from the equipment being tested, high or low temperatures) shall be avoided by
proper selection or positioning of the microphone.
The instructions of the manufacturers of the measurement instruments regarding adverse
environmental conditions shall be followed. The microphone shall always be oriented in such
a way that the angle of incidence of the sound waves is that for which the microphone is
calibrated.
4.5 Measurement uncertainties
4.5.1 General
The estimated values of the standard deviations of reproducibility of sound power levels
determined in accordance with this document are given in 9.1 of ISO 3743-1:2010, in 11.1 of
ISO 3743‑2:2018 and in 9.1 of ISO 3744:2010. But for a particular family of appliances of
similar size with similar operating conditions, the standard deviations of reproducibility can be
smaller than these values. Hence, in the IEC 60704-2 series, standard deviations smaller than
those listed in ISO standards can be stated if substantiation is available from the results of
suitable interlaboratory tests.
In the case of discrepancies between the measurements where the results normally remain
inside the foreseen standard deviation, it can be helpful to perform measurements according
to the upper grade of accuracy: grade 1, laboratory or precision, as described in ISO 3741 or
ISO 3745.
4.5.2 Standard deviations on repeatability and reproducibility and standard
deviations related to declaration and verification
The standard deviations on repeatability and reproducibility of sound power levels determined
in accordance with this document are indicated in tables in the IEC 60704-2 series and in
IEC 60704-3. Tables in the IEC 60704-2 series are given in the format shown in Table 1.
Values (X,X) are given to one decimal place.
– 12 – IEC 60704-1:2021 © IEC 2021
Table 1 – Standard deviations of sound power levels
Standard deviation (dB)
σ (repeatability) σ (reproducibility)
r R
X,X X,X
Standard deviations (on production, total and reference) for the purpose of determining and
verifying declared noise emission values in accordance with IEC 60704-3 are provided in the
IEC 60704-2 series and in IEC 60704-3. Tables in the IEC 60704-2 series are given in the
format shown in Table 2. Values are given to one decimal place.
Table 2 – Standard deviations for declaration and verification
Standard deviation (dB)
σ (production) σ (total) σ (reference)
P t M
X,X X,X X,X
5 Instrumentation
5.1 Instrumentation for measuring acoustical data
Requirements for the instrumentation system and for its calibration are given in Clause 5 of
ISO 3743-1:2010, in Clause 7 of ISO 3743-2:2018 and in Clause 5 of ISO 3744:2010.
The instrumentation system shall meet the requirements for a type 1 instrument laid down in
IEC 61672-1:2013, in accordance with the basic standard used. For measurements in octave-
and 1/3 octave-bands, the instrumentation system shall meet the requirements of
IEC 61260‑1:2014.
RSS shall meet the requirements of ISO 6926:2016, and shall be calibrated annually.
5.2 Instrumentation for measuring climatic conditions
5.2.1 The temperature is determined with instruments having an accuracy of ±1 °C.
5.2.2 The relative humidity is determined with instruments having an absolute accuracy of
±2 % within the measuring range.
5.2.3 The absolute air pressure is determined with instruments having an accuracy of
±0,5 kPa.
5.3 Instrumentation for measuring operating conditions
5.3.1 The voltage at the plug of the cable or cord of mains-powered appliances is
measured with voltmeters having an accuracy of class 0,5 instruments.
5.3.2 The voltage at the battery terminals of battery-powered appliances is measured with
voltmeters having an accuracy of class 0,5 instruments.
5.3.3 The rotational speed of motors, attachments, etc. is measured, if necessary, with
speed indicators having an accuracy of ±1 % of full scale.
IEC 60704-1:2021 © IEC 2021 – 13 –
6 Operation and location of appliances under test
6.1 Equipping and pre-conditioning of appliances
6.1.1 The appliance is equipped with attachments, accessories, etc. as delivered by the
manufacturer for the intended use or function.
6.1.2 Care shall be taken to ensure that any auxiliary equipment (such as electrical
conduits or cables, piping for water supply or drainage, air ducts, etc.) necessary for the
operation of the appliance, does not radiate a significant amount of sound into the test
environment or change the sound output of the appliance. Guidelines are given in 6.2 of
ISO 3743-1:2010, in 8.4 of ISO 3743-2:2018 and in 6.2 ISO 3744:2010.
6.1.3 Prior to noise measurements, the appliance, equipped as for intended use, shall
have been in operation long enough to prevent excessive noise due to parts not being run in.
Running-in should take place at the highest speed setting, if any, and unless otherwise
stated, without load. The relevant part of IE
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