EN 60704-1:1997

SLOVENSKI STANDARD
01-februar-2001
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
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: Règles générales
Ta slovenski standard je istoveten z: EN 60704-1:1997
ICS:
17.140.20 Emisija hrupa naprav in Noise emitted by machines
opreme and equipment
97.030 (OHNWULþQLDSDUDWL]DGRPQD Domestic electrical
VSORãQR appliances in general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

NORME
CEI
INTERNATIONALE
IEC
60704-1
INTERNATIONAL
Deuxième édition
STANDARD
Second edition
1997-02
Appareils électrodomestiques et analogues –
Code d'essai pour la détermination du bruit aérien –
Partie 1:
Règles générales
Household and similar electrical appliances –
Test code for the determination of airborne
acoustical noise –
Part 1:
General requirements
 IEC 1997 Droits de reproduction réservés  Copyright - all rights reserved
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CODE PRIX
Commission Electrotechnique Internationale
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International Electrotechnical Commission
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60704-1  IEC:1997 − 3 −
CONTENTS
Page
FOREWORD . 5
INTRODUCTION . 7
Clause
1 Scope and object. 9
2 Normative references . 11
3 Terms and definitions . 13
4 Measurement methods and acoustical environments . 15
5 Instrumentation . 19
6 Operation and location of appliances under test . 21
7 Measurements of sound pressure levels . 27
8 Calculation of sound pressure and sound power levels. 35
9 Information to be recorded . 39
10 Information to be reported . 45
Figures
1 Measurement surface − parallelepiped − with key microphone positions,
for floor free-standing appliances . 49
2 Measurement surface − parallelepiped − with key microphone positions,
for floor-standing appliances placed against a wall . 49
3 Measurement surface − parallelepiped − with key microphone positions,
for high floor-standing appliances placed against a wall . 50
4 Measurement surface − hemisphere − with key microphone positions for hand-held,
table-type and floor-treatment appliances. 51
5 Measurement surface − quarter-sphere − with key microphone positions for small
floor-standing appliances placed against a wall . 52
6 Measurement surface − parallelepiped − with five or nine microphone positions
for stand-type appliances. 53
Annexes
A Standard test table . 55
B Guidelines for the design of simple test rooms with essentially free-field conditions . 57

60704-1  IEC:1997 − 5 −
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
HOUSEHOLD AND SIMILAR ELECTRICAL APPLIANCES –
TEST CODE FOR THE DETERMINATION OF AIRBORNE
ACOUSTICAL NOISE –
Part 1: General requirements
FOREWORD
1) The IEC (International Electrotechnical Commission) is a worldwide organization for standardization
comprising all national electrotechnical committees (IEC National Committees). The object of the 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, the IEC publishes International Standards. 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. The 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 the 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 National Committees.
3) The documents produced have the form of recommendations for international use and are published in the
form of standards, technical reports or guides and they are accepted by the National Committees in that
sense.
4) In order to promote international unification, IEC National Committees undertake to apply IEC International
Standards transparently to the maximum extent possible in their national and regional standards. Any
divergence between the IEC Standard and the corresponding national or regional standard shall be clearly
indicated in the latter.
5) The IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with one of its standards.
6) Attention is drawn to the possibility that some of the elements of this International Standard may be the
subject of patent rights. The 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 electrical appliances.
This second edition cancels and replaces the first edition published in 1982 and constitutes a
technical revision. It includes the conditions for using hard-walled test rooms and introduces
the concept of time-averaged sound pressure level.
The text of this standard is based on the following documents:
FDIS Report on voting
59/162/FDIS 59/173/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
Annex A forms an integral part of this standard.
Annex B is for information only.

60704-1  IEC:1997 − 7 −
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) should be kept at a modest level.
The results of noise measurements will be 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 will be 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,
ISO 3743-2 and ISO 3744.
The adoption of these methods permits the use of semi-anechoïc 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 and
2)
ISO 9614-2 is under consideration.
It should be emphasized that this test code is concerned with airborne noise only. In some
cases, structure-borne noise, for example transmitted to the adjoining room, may be of
importance.
_________
)
ISO 9614-1: 1993, Acoustics − Determination of sound power levels of noise sources using sound intensity −
Part 1: Measurement.
)
ISO/DIS 9614-2: 1996, Acoustics − Determination of sound power levels of noise sources using sound intensity −
Part 2: Measurement by scanning.

60704-1  IEC:1997 − 9 −
HOUSEHOLD AND SIMILAR ELECTRICAL APPLIANCES –
TEST CODE FOR THE DETERMINATION OF AIRBORNE
ACOUSTICAL NOISE –
Part 1: General requirements
1 Scope and object
1.1 Scope
General
1.1.1
This part of IEC 704 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 similar conditions as in households, for example in inns,
coffee-houses, tea-rooms, hotels, barber or hairdresser shops, launderettes, etc., if not
otherwise specified in part 2.
This standard does not apply to:
– appliances, equipment or machines designed exclusively for industrial or professional
purposes;
– appliances which are integrated parts of a building or its installations, such as equipment
for air conditioning, heating and ventilating (except household fans, cooker hoods and free
standing heating appliances), oil burners for central heating, pumps for water supply and for
sewage systems;
– separate motors or generators;
– appliances for outdoor use.
1.1.2 Types of noise
A classification of different types of noise is given in ISO 12001. The method specified in
ISO 3744 is suitable for measurements of all types of noise emitted by household appliances.
The methods specified in ISO 3743-1 and ISO 3743-2 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 2.
1.1.3 Size of the source
The method specified in ISO 3744 is applicable to noise sources of any size. Limitations for the
size of the source are given in 1.2.2 of ISO 3743-1 and ISO 3743-2. This will be taken into
account in the preparation of parts 2.
Object
1.2
This standard is concerned with objective methods of engineering accuracy (grade 2 according
to ISO 12001) for determining sound power levels L , expressed in decibels (dB) with
W
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.
60704-1  IEC:1997 − 11 −
The following quantities are used:
– A-weighted sound power level, L ; and
WA
– octave band sound power levels.
In general, the described methods are specified for appliances without an operator present. A
part 2 can specify that an operator will be present only for the (rare) cases where an appliance
can only be operated, or must be fed, by an operator.
Methods for determining sound power levels with precision accuracy (grade 1 according to
ISO 12001), specified for example in ISO 3741 and ISO 3745, are not included in this standard.
They may, however, be applied if the appropriate test environment and instrumentation are
available.
NOTES
1 The noise values obtained under the described conditions of this part will not necessarily correspond with
the noise experienced under the operational conditions of practical use.
2 For quality control during production etc., simplified methods may be appropriate. For noise reduction
purposes, other measurement methods employing, for example, narrow-band analysis or intensity technics
usually will have to be applied. These methods are not covered by this part.
1.3 Measurement uncertainty
The estimated values of the standard deviations of reproducibility of sound power levels
determined according to this part are given in 1.4 of ISO 3743-1 and of ISO 3743-2, and in 1.4
of ISO 3744. But for a particular family of appliances of similar size with similar operating
conditions, the standard deviations of reproducibility may be smaller than these values. Hence,
in part 2, standard deviations smaller than those listed in ISO standards may be stated if
substantiation is available from the results of suitable interlaboratory tests.
IEC 704-3 gives values of standard deviations of reproducibility for several categories of
appliances.
In case of discrepancies between the measurements where the results normally remain inside
the foreseen standard deviation, it will be necessary to perform measurements according to the
upper grade of accuracy: grade 1, laboratory or precision, as described in ISO 3741 or
ISO 3745.
2 Normative references
The following normative documents contain provisions which, through reference in this text,
constitute provisions of this part of IEC 704. At the time of publication, the editions indicated
were valid. All standards are subject to revision, and parties to agreements based on this part
of IEC 704 are encouraged to investigate the possibility of applying the most recent editions of
the standards indicated below. Members of IEC and ISO maintain registers of currently valid
International Standards.
IEC 651: 1979, Sound level meters
IEC 704-3: 1992, Test code for the determination of airborne acoustical noise emitted by
household and similar electrical appliances – Part 3: Procedure for determining and verifying
declared noise emission values

60704-1  IEC:1997 − 13 −
IEC 804: 1985, Integrating-averaging sound level meters
IEC 1260: 1995, Electroacoustics – Octave band and fractional – octave band filters
ISO 3741: 1988, Acoustics – Determination of sound power levels of noise sources – Precision
methods for broad-band sources in reverberation rooms
ISO 3742: 1988, Acoustics – Determination of sound power levels of noise sources – Precision
methods for discrete frequency and narrow-band sources in reverberation rooms
ISO 3743-1: 1994, Acoustics – Determination of sound power levels of noise sources –
Engineering methods for small, movable sources in reverberant fields using sound pressure –
Part 1: Comparison method in hard-walled test rooms
ISO 3743-2: 1994, Acoustics – Determination of sound power levels of noise sources –
Engineering methods for small, movable sources in reverberant fields using sound pressure –
Part 2: Methods for special reverberation test rooms
ISO 3744: 1994, Acoustics – Determination of sound power levels of noise sources using
sound pressure – Engineering method in an essentially free-field over a reflecting plane
ISO 3745: 1977, Acoustics – Determination of sound power levels of noise sources – Precision
method for anechoic and semi-anechoic rooms
ISO 6926: 1990, Acoustics – Determination of sound power levels of noise sources –
Requirements for the performance and calibration of reference sound sources
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 part of IEC 704, the following definitions apply:
3.1 terms and definitions pertinent to determination of sound power levels: These may
be found in ISO 3743-1, ISO 3743-2 and ISO 3744.
3.2 measurement time interval: A portion or a multiple of an operational period or
operational cycle for which the sound power levels are determined.
3.3 operational period: An 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).

60704-1  IEC:1997 − 15 −
3.4 operational cycle: A specific sequence of operational periods occurring while the
appliance under test performs a complete work cycle. During the operational cycle, each
operational period is associated with a specific process that may occur only once, or may be
repeated, (for example, for a dishwasher, washing and rinsing and drying).
3.5 time history: A 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.
3.6 standard test operator: A person necessary for operating or feeding the appliance
under test, not wearing abnormally sound absorptive clothing which might influence the sound
measurements.
3.7 centre of location or position of a source: The term used for describing the location or
position of the source (appliance) to be tested within the test environment and, in free-field
environment, with respect to the co-ordinate system of microphone positions.
The centre of location is such that the centre of the appliance coincides with the centre of a
parallelepiped drawn around the main part of hand-held, suspended, or stand-type appliances.
The centre of location is such that the centre of the appliance coincides with the centre of a
rectangle drawn around the projection of the main part of the appliance on the floor, for floor-
supported appliances, and on the wall, for wall-mounted appliances.
4 Measurement methods and acoustical environments
4.1 General
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. The sound
power of a machine is essentially 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 decibels
WA
(ref. 1 pW).
According to this standard, two principal methods exist, the direct method and the comparison
method, as described in 4.2 and 4.3 below. These two methods can be used alternatively.
Different types of environments, as described in 4.4, may be used. A part 2 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 according
to ISO 3744 for free-field conditions over reflecting plane(s), and according to ISO 3743-2 for
special reverberation test rooms.

60704-1  IEC:1997 − 17 −
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;
– in special reverberation test rooms, from averaged sound pressure levels, and from the
reverberation time and the volume of the test room.
This method yields results expressed in A-weighted sound power levels (and in octave-band
sound power levels, if required) which are calculated directly from measured sound pressure
levels.
NOTE – This method can also be used in conjunction with more precise methods, as for instance as given in
ISO 3741, ISO 3742 and ISO 3745.
4.3 Comparison method
The comparison method for measurement is explicitly described in ISO 3743-1 and in
ISO 3743-2.
NOTE – The term “comparison method" is not explicitly given in ISO 3744, but when applying the “absolute
comparison test" for the determination of the environmental correction given in clause A.3 of ISO 3744, 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. 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-band sound power levels, and the A-weighted
sound power level is calculated from the 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 clause 4 of:
− ISO 3743-1 for hard-walled test rooms;
− ISO 3743-2 for special reverberation test rooms;
− ISO 3744 for free-field conditions over reflecting plane.
NOTE – For free-field conditions over reflecting plane, the absolute comparison test for the qualification of the
environment, described in clause A.3, annex A of ISO 3744, is preferred.
Guidelines for the design of simple test rooms with free-field conditions are given in annex A of
this standard.
60704-1  IEC:1997 − 19 −
Guidelines for the design of a suitable special reverberation test room are given in annex A of
ISO 3743-2.
4.4.2 Criterion for background noise level
Requirements for the background noise level are given in clause 4 of ISO 3743-1, ISO 3743-2
and ISO 3744. 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 8.1.
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.
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, ISO 3743-2 and ISO 3744.
The instrumentation system shall meet the requirements for a type 1 instrument laid down in
IEC 651 or IEC 804, according to the basic standard used. For measurements in octave bands,
the instrumentation system shall meet the requirements of IEC 1260.
Reference sound sources (RSS) shall meet the requirements of ISO 6926, 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.
Instrumentation for measuring operating conditions
5.3
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.

60704-1  IEC:1997 − 21 −
6 Operation and location of appliances under test
Equipping and pre-conditioning of appliances
6.1
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 energy into the test environment or
change the sound output of the appliance. Guidelines are given in 6.4 of ISO 3743-1,
ISO 3743-2 and ISO 3744.
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 part 2 shall indicate the total period for running-in and the rated operating
times, unless the manufacturer has recommended otherwise.
6.1.4 Immediately before each series of noise measurements, the appliance, equipped as for
the intended use, is operated for stabilizing at the highest speed setting, if any and unless
otherwise stated, without load, as indicated in part 2 or according to the manufacturer's
instructions.
Supply of electric energy and of water or gas
6.2
6.2.1 Appliances with mains powered electric motor(s) are supplied at rated voltage with a
tolerance of ±1 %, and, if applicable at rated frequency. Appliances designed for d.c. only are
supplied with d.c. Appliances not marked with rated frequency are supplied either with 50 Hz or
with 60 Hz, as common in the country of use, with a tolerance of ±1 %.
Appliances designed for a voltage range are supplied with the mean voltage of the range and
the same tolerances as specified before, if the difference between the limits of the range does
not exceed 10 % of the mean voltage of the range. If the difference exceeds 10 %, the
appliance is supplied with the highest voltage of the range and the same tolerances as
specified before.
The supply voltage is measured at the plug of a non-detachable cable or cord, or at the
appliance inlet if a detachable cable is provided, but in no case at the entrance of extension
cables or cords.
NOTE – When, in some countries, the rated voltage/frequency differs from the nominal system
voltage/frequency of the country concerned, measurements carried out at rated voltage/frequency may be
misleading for the consumer. In that case, additional measurements may be necessary. If the test
voltage/frequency differs from the rated voltage/frequency, this should be reported.
6.2.2 Appliances with battery-powered electric motor(s) are started, for noise measurements,
with full-charged batteries as specified by the manufacturer, and the measurements are
interrupted when the battery voltage under load has dropped for lead-acid batteries to 0,9 times
and for other batteries to 0,8 times the battery voltage under load at the beginning of the test.
The battery voltage is measured at the battery terminals.

60704-1  IEC:1997 − 23 −
6.2.3 Appliances incorporating heating, either electric or gas, may be operated without
heating, if the heating does not change the noise emission of the appliance.
6.2.4 The water and/or gas supply, if any, shall be as specified by the manufacturer.
If not specified by the manufacturer, the water supply pressure shall be 240 kPa ± 50 kPa, the
temperature of cold water shall be +15 °C ± 2 °C and the temperature of hot water shall be
+55 °C ± 2 °C, unless otherwise specified in part 2.
NOTE – When, in some countries, the water supply pressure/temperature differs from the water supply
pressure/temperature of the country concerned, measurements carried out at rated pressure/temperature may
be misleading for the consumer. In this case, additional measurements may be necessary. If the test
pressure/temperature differs from the rated pressure/temperature, this should be reported.
6.3 Climatic conditions
In general, household appliances (unless otherwise specified for a special family) are operated
under the following climatic conditions:
ambient temperature      t  = 20 °C ± 5 °C
relative humidity          RH = 50 % ± 20 %
atmospheric pressure      p = 96 kPa ± 10 kPa
s
6.4 Loading and operating of appliances during tests
General requirements are given in 6.5 of ISO 3743-1, ISO 3743-2 and ISO 3744. For the
purpose of establishing a noise test code, the following guidelines are given, unless otherwise
specified in part 2:
6.4.1 In general, the loading and operating conditions should, as far as practicable, simulate
normal use but, in every case, preference has to be given to simple conditions providing a
satisfactory repeatability and reproducibility.
The presence of an operator should be avoided. An operator shall be present only if the
application of the load is not practicable without an operator.
6.4.2 For determining noise emission of an appliance, the loading and operating conditions, if
not specified for a particular category of appliances in part 2, shall be restricted to one single
condition, except for appliances with multiple main functions of long duration and for multi-
purpose appliances, where one or several conditions may be specified.
The idling condition may be chosen as the sole condition for determining noise emission of the
appliance if it is typical and steady and if the reproducibility with the loading condition is poor.
For appliances provided with speed control, in general the highest speed setting is used.

60704-1  IEC:1997 − 25 −
6.4.3 Appliances operated during normal use in operational cycles are operated likewise for
determining noise emission, taking measurements during appropriate parts of the operational
cycles of the main functions.
NOTE – It is recommended to record the A-weighted sound pressure level during the operational cycle(s) – time
history – at one of the microphone positions, preferably in front of the appliance to be tested.
6.4.4 When applying loading and operating conditions for determining noise emission, care
shall be taken to avoid possible overheating of the appliance under test. Rated operating and
resting times and/or the manufacturer's instructions shall be followed.
6.5 Location and mounting of appliances
The basic requirements of 6.2 and 6.3 of ISO 3743-1, ISO 3743-2 and ISO 3744 shall be
followed. For the purpose of establishing a noise test code the following guidelines are given,
unless otherwise specified in part 2:
6.5.1 Floor-standing appliances, counter-top or table-type appliances, are placed in normal
position directly, without any resilient means other than those incorporated in the appliance:
– either on the floor of the hard-walled test room or of the special reverberation test room
with a minimum distance of 1 m between any surface (including protruding parts)
of the appliance and the nearest wall;
– or on the reflecting plane of the free-field environment, taking into account the shape
and size of the specified measurement surface.
Stand-type appliances (such as appliances designed for use on a stand, for example,
hairdrying hoods) are placed on the stand supplied with the appliance, or on a stand
constructed according to the manufacturer's instructions.
NOTE – Sound radiation due to possible vibrations of the piece of floor covering must be prevented. The piece
of floor covering is considered to be a part of the appliance under test, and its possible influence on the
acoustical characteristics of the test environment is not taken into account.
Table-top appliances, where a table is required for operation, are placed in the centre of the
top of the standard test table described in annex B.
6.5.2 Hand-held appliances, including their accessories, if any, are resiliently suspended or
resiliently mounted in an adequate test fixture at a height of approximately 25 cm.
The base of the test fixture is placed on an intermediate resilient means (having no influence
on the airborne noise emitted by the appliance under test), so that structure-borne noise is not
transmitted from the appliance, and is located:
– either on the floor of the hard-walled test room or of the special reverberation test room
with a minimum distance of 1 m between any surface (including protruding parts)
of the appliance and the nearest wall;
– or on the reflecting plane of the free-field environment, taking into account the shape
and size of the specified measurement surface.

60704-1  IEC:1997 − 27 −
NOTE – Care should be taken to ensure that the means of suspension or clamping do not change the sound
output of the appliance, for example radiated by the floor, or by suppressing or emphasizing special modes of
vibration of the body of the appliance, or by covering radiating surfaces, air intakes, etc.
6.5.3 Floor-standing appliances, including cabinets or counters for built-in appliances, for
placing on the floor against a wall, are placed in normal position, with a distance of 15 cm ± 5
cm between the back of the appliance and a vertical wall or reflecting plane, taking care to
avoid contact of protruding parts with the wall or plane, directly, without any resilient means
other than those incorporated in the appliance:
– either on the floor of the hard-walled test room or of the special reverberation test room
with the mentioned distance of 15 cm ± 5 cm of the back from a wall and with a
minimum distance of 1,5 m between any other surface of the appliance or of the
cabinet or the counter from the nearest corner of the room;
– or on the reflecting plane of the free-field environment and with the mentioned
distance of 15 cm ± 5 cm between the back of the appliance and the second
vertical reflecting plane, taking into account the shape and size of the specified
measurement surface.
6.5.4 Wall-mounted appliances, including their accessories, if any, are fastened or held by an
appropriate fixture in close contact, without any resilient means other than those incorporated
in the appliance:
– either on a wall of the hard-walled test room or of the special reverberation test room;
– or on a second reflecting plane of the free-field environment.
The height of the lowest edge of the appliance from the floor shall be fixed according to the
manufacturer's instructions.
The location of the appliance (fastened or held in an appropriate fixture) as for floor-standing
appliances (see 6.5.1) may be adopted, if preliminary investigation has shown that the resulting
sound power level value is not significantly different from that determined with the location
prescribed in this subclause.
6.5.5 Appliances destined to be built-in are built-in according to the manufacturer's
instructions in appropriate cabinets or counters.
7 Measurement of sound pressure levels
Microphone array, measurement surface and RSS location for
7.1
essentially free-field conditions over reflecting plane(s)
The requirements of 7.1 to 7.4 of ISO 3744 shall be followed. Guidance for the selection of the
measurement surface and microphone array in part 2 are given below; care shall be taken to
use only one of the following two shapes and one of the possible microphone arrays for a
particular family of appliances, unless otherwise specified in part 2.
7.1.1 For floor-standing free-standing appliances, including built-in appliances, the measure-
ment surface is a parallelepiped with nine microphone positions, as specified in 7.3.1 of
ISO 3744 and in figure 1 of this standard. Additional measurement positions can be required
according to 7.3.2 of ISO 3744. The number of microphone positions can also be reduced
according to 7.4.2 of ISO 3744.

60704-1  IEC:1997 − 29 −
NOTE – The front of the appliance, unless otherwise stated in part 2, is directed in the direction of the x-axis.
d
The preferred value of the measurement distance is 1 m.
For determining time histories, frequency spectra, etc. of the appliance, the microphone position no. 1 is
recommended for the nine microphone array.
7.1.2 For floor-standing or counter-type appliances for placing against a wall, including built-
in appliances, the measurement surface is a parallelepiped, with six microphone positions, as
specified in 7.3.1 of ISO 3744 and in figure 2 of this standard. Additional measurement
positions can be required according to 7.3.2 of ISO 3744. The number of microphones can also
be reduced according to 7.4.2 of ISO 3744.
NOTE – The front of the appliance is directed in the direction of the x-axis.
The preferred value of the measurement surface d is 1 m.
For determining time histories, frequency spectra, etc. of the appliance, the microphone position no. 1 is
recommended for the six microphone array.
This measurement surface can also be used for wall-mounted appliances.
NOTE – In this case, the x and y axes are located in the vertical reflecting plane, with the x-axis directed
vertically upwards and the front of the appliance being directed in the direction of the z-axis.
7.1.3 For floor-standing cabinet-type appliances for placing against a wall, including built-in
d d
appliances of larger size with a height exceeding 2 , but less than or equal to 5 , the
measurement surface is a parallelepiped with 10 microphone positions as specified in figure 3
of this standard. The points 9 and 10 are suppressed when not practicable (for example,
appliances in contact with the ceiling). Additional measurement positions may be required
according to 7.3.2 of ISO 3744. The number of microphones can also be reduced according to
7.4.2 of ISO 3744.
NOTE – The front of the appliance is directed in the direction of the x-axis.
The preferred value of the measurement surface d is 1 m.
For determining time histories, frequency spectra, etc. of the appliance, the microphone position no. 7 is
recommended for the 10 microphone array.
7.1.4 For counter-top or table-type appliances, floor treatment appliances and hand-held
appliances (mounted in test fixtures), with each of the dimensions of the reference box not
exceeding 0,7 m, and placed during measurements on the horizontal reflecting plane, the
measurement surface is a hemisphere with 10 microphone positions, as specified in 7.2.1 of
ISO 3744 and shown in figure 4 of this standard. Additional measurement positions can be
required according to 7.2.2 of ISO 3744. In special cases, a different number and arrangement
of microphone positions can be used, if the requirements of 7.2.1 of ISO 3744 are satisfied.
If the reference box has a dimension exceeding 0,7 m, the microphone array and measurement
surface described in 7.1.1 shall be used.
The radius r, of the hemispherical measurement surface preferably shall be equal to 2 m, but in
any case not less than 1,5 m.
NOTE – The front of the appliance, unless otherwise specified in part 2, is directed in the direction of the x-axis.
For determining time histories, frequency spectra, etc. of the appliance, the microphone position no. 8 is
recommended for the 10 microphone array.

60704-1  IEC:1997 − 31 −
7.1.5 For small floor-standing appliances for placing against a wall (for example shoe-
polishers), with the dimensions of the reference box, l and l each not exceeding 0,4 m and l

1 3 2
not exceeding 0,8 m, the measurement surface is a quarter-sphere with five microphone
positions, as specified in 7.2.1 of ISO 3744 and shown in figure 5 of this standard.
NOTE – For determining time histories, frequency spectra, etc. of the appliance, the microphone position no. 6
is recommended for the five microphone array.
7.1.6 For stand-type appliances, with the height of the geometric centre of the reference box
above the floor exceeding in normal use 1,0 m, the measurement surface is a parallelepiped
with five microphone positions as specified in figure 6 of this standard, centred in the centre of
the reference box. Four positions are regularly spaced at 1 m from the outlines of the
appliance, in a plane going through its geometrical centre and parallel to the reflecting plane;
the fifth position shall be situated at a distance of 1 m from the above described plane. The co-
ordinate system describing the microphone positions is located with the x and y axis in the
horizontal reflecting plane and the z axis at right angles to it.
In general, the number of measuring points is sufficient if the difference, in decibels, between
the maximum and minimum measured sound pressure levels is less than 5 dB. If this condition
is not fulfilled, it is necessary to carry out measurements in four additional points 6 to 9, as
described in figure 6.
The area of this measurement surface is given by:
S = 4 (ab + bc + ca)
where
c is the height, in metres, of the measurement surface (normally equal to the height of the
geometrical centre of the appliance above the reflecting plane, enlarged by 1 m);
2a is the width, in metres, of the measurement surface (normally equal to the width of the
appliance, enlarged by 2 m);
2b is the length, in metres, of the measurement surface (normally equal to the maximum
dimension of the appliance, enlarged by 2 m).
NOTE – The front of the appliance, unless otherwise specified in part 2, is directed in the direction of the x-axis.
For determining time histories, frequency spectra, etc. of the appliance, the microphone position no. 1 is
recommended.
7.1.7 If the appliance under test emits steady noise, it is permissible to measure the surface
sound pressure level by traversing a microphone along measurement paths, instead of at
individual microph
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