EN 61063:1996

SLOVENSKI STANDARD
01-junij-2000
Acoustics - Measurement of airborne noise emitted by steam turbines and driven
machinery
Acoustics - Measurement of airborne noise emitted by steam turbines and driven
machinery
Akustik - Messung von luftübertragenen Geräuschen emittiert von Dampfturbinen und
angetriebenen Maschinen
Acoustique - Mesure du bruit aérien émis par les turbines à vapeur et les machines
entraînées
Ta slovenski standard je istoveten z: EN 61063:1996
ICS:
17.140.20 Emisija hrupa naprav in Noise emitted by machines
opreme and equipment
27.040 Plinske in parne turbine. Gas and steam turbines.
Parni stroji Steam engines
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

NORME CEI
INTERNATIONALE IEC
INTERNATIONAL
Première édition
STAN DARD
First edition
1991-04
Acoustique — Mesure du bruit aérien
émis par les turbines à vapeur et les
machines entraînées
Acoustics — Measurement of airborne
noise emitted by steam turbines and
driven machinery
© IEC 1991 Droits de reproduction réservés — Copyright - all rights reserved
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1063©IEC
CONTENTS
Page
FOREWORD 5
INTRODUCTION 7
Clause
1 Scope 9
2 Normative references
3 Definitions
Acoustic environment
Instrumentation 5
Installation and operation of turbine set 6
19 7 Measurement of A-weighted sound pressure level
25 Calculation of surface sound pressure level and sound power level
9 Information to be recorded
10 Information to be reported
qualification procedure ANNEX A - Test environment

1063©IEC — 5 —
INTERNATIONAL ELECTROTECHNICAL COMMISSION
ACOUSTICS - MEASUREMENT OF AIRBORNE NOISE
EMITTED BY STEAM TURBINES AND DRIVEN MACHINERY
FOREWORD
The formal decisions or agreements of the IEC on technical matters, prepared by Technical Committees on
1)
which all the National Committees having a special interest therein are represented, express, as nearly as
possible, an international consensus of opinion on the subjects dealt with.
2) They have the form of recommendations for international use and they are accepted by the National
Committees in that sense.
3) In order to promote international unification, the IEC expresses the wish that all National Committees
should adopt the text of the IEC recommendation for their national rules in so far as national conditions will
permit. Any divergence between the IEC recommendation and the corresponding national rules should, as
far as possible, be clearly indicated in the latter.
This International Standard has been prepared by IEC Technical Committee No. 5: Steam
turbines.
The text of this standard is based on the following documents:
Six Months' Rule Report on Voting
5(CO)29 5(CO)32
Full information on the voting for the approval of this standard can be found in the Voting
Report indicated in the above table.
Annex A forms an integral part of this International Standard

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INTRODUCTION
This standard is based on ISO 3746 and has been drafted in accordance with ISO 3740.
The main purpose of this standard is to describe a method for the measurement of noise
radiated by steam-turbines including driven machinery operating under steady state
conditions. The results are expressed in sound power levels and in sound pressure levels.
NOTE - For special environmental conditions, it may be possible to use the engineering methods based
on ISO 3744 resulting in a higher grade of accuracy. In this case no reference to this standard will be
made.
– 9 –
1063©IEC
ACOUSTICS - MEASUREMENT OF AIRBORNE NOISE
EMITTED BY STEAM TURBINES AND DRIVEN MACHINERY
1 Scope
1.1 General
1.1.1 This International Standard applies to the measurement of airborne noise emitted
by assemblies comprising steam turbines and driven machinery, hereinafter referred to as
turbine sets. These sets are of all sizes without limitation of output when fitted with their
rt of the turbine set (turbine,
normal auxiliaries. This standard applies only to the pa
generator and attached components) located above the floor of the turbine room and in-
side a continuous enveloping measurement surface bounded by this floor.
An extensive and continuous turbine operating floor of a reflecting nature above the
turbine foundation floor level shall be considered as the reflecting plane.
1.1.2 In the case of large turbine sets, the turbine operating floor is often located below
and near the horizontal centreline of the turbine (see figure 1). If this floor is continuous
and free from openings which would otherwise allow noise radiated below the turbine
operating floor to influence the noise measured at microphone locations, a valid measure
of the turbine set noise emission may be obtained by use of this standard.
Enveloping measurement surface
r
Turbine
Generator
\—
HP LP
LP
Operating floor
\ /
Auxiliaries
Condensate pumps
Condenser
Foundation floor
(feedwater pumps are
on the ground floor)
IEC 197/9!
Figure 1 - General situation of the turbine sets, including their
ancillaries and auxiliaries
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1.1.3 In the case where the turbine operating floor is located below and near the
horizontal centerline of the turbine set, but consists of:
an open grating construction, or
a)
b) a solid floor with openings near to the boundary of the turbine set, or
c) walkways typically 1 to 2 m wide of either solid or grated construction,
the turbine operating floor cannot be considered as a reflecting plane. In this case the
reflecting plane will be the turbine set foundation floor.
rface being bounded by either
In the case of the continuous enveloping measurement su
the turbine operating floor or the turbine foundation floor, a large contribution from the
noise of ancillary and auxiliary plant located below the turbine operating floor may be
expected at the microphone measuring positions. In this case the use of this standard for
the determination of sound power levels is not valid.
If this standard is to be employed for the purpose of the comparison of the 1 m sound
rface
levels of similar turbines, the turbine operating floor shall be used as the bounding su
rface. The validity of comparative measure-
for the continuous enveloping measurement su
ments will depend on the noise present at the measurement positions due to auxiliary and
ancillary plant and it will be necessary to define exactly the number, type and location of
these items.
It is preferable to establish the effect auxiliary and ancillary plant noise radiation will have
on the sound level at the microphone locations by determining the noise emission of these
items in accordance with ISO 3746, and determining the propagation of this noise to micro-
phone locations. However, this procedure is beyond the scope of this standard.
NOTE - When openings in the floor are suitably blocked during the test with appropriate panels (upper
side of panels should have same reflective characteristics as the turbine operating floor), valid measure-
ments are permitted.
1.1.4 In the case of turbine sets mounted on, or partially submerged in, the foundation
floor, which may also be defined as the turbine operating floor, a valid measure of the
turbine set noise emission may be obtained by use of this standard.
1.1.5 Where noise control treatments such as enclosures and/or screens are fitted to the
turbine set, driven equipment and auxiliaries, the type, location and extent of treatment
shall be reported.
1.2
Measurement uncertainty
Measurements made in conformity with this standard tend to result in standard deviations
which are equal to or less than those given in table 1.

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Table 1 - Uncertainty in determining A-weighted sound power level
by the survey method
Standard deviation
Application
dB
For a source which produces sounds that
contain prominent discrete tones
For a source which produces sounds that are
uniformly distributed in frequency over the
frequency range of interest
NOTES
1 If the method specified in this standard is used to compare the sound power levels of similar machines
that are omnidirectional and radiate broad band noise, the uncertainty in this comparison tends to result in
a standard deviation which is equal to or less than 3 dB provided that the measurements are performed in
similar environments.
2 The standard deviations given in this table reflect the cumulative effects of all causes of measurement
uncertainty, excluding variations in the sound power level from machine to machine or from test to test
which may be caused, for example, by changes in the mounting or operating conditions of the source. The
reproducibility and repeatability of the test results may be considerably better (i.e. indicate smaller
deviations) than the uncertainties given in table 1 would indicate.
3 The standard deviations given above are considered, in the light of the experimental evidence
available, to be conservative.
2 Normative references
The following standards contain provisions which, through reference in this text, constitute
provisions of this International Standard. At the time of publication, the editions indicated
were valid. All standards are subject to revision, and parties to agreements based on this
International Standard 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 50(801): 1984,
International Electrotechnical Vocabulary (IEV) Chapter 801: Acoustics
and electro-acoustics.
IEC 268-4: 1972,
Sound-system equipment - Pa rt 4: Microphones.
IEC 651: 1979,
Sound level meters.
ISO 3740: 1980, Acoustics - Determination of sound power levels of noise sources -
Guidelines for the use of basic standards and for the preparation of noise test codes.

1063 ©IEC - 15 -
ISO 3744: 1981, Acoustics - Determination of sound power levels of noise sources -
Engineering methods for free-field conditions over a reflecting plane.
ISO 3746: 1979, Acoustics - Determination of sound power levels of noise sources -
Survey method.
ISO 6926-2, Acoustics - Determination of sound power levels of noise sources -
Requirements for the performances and calibration of reference sound sources. (In
preparation.)
3 Definitions
For the purpose of this International Standard the following definitions apply:
3.1 sound pressure level, LP, in decibels: Twenty times the logarithm to the base 10
of the ratio of the sound pressure to the reference sound pressure. The weighting network
LPA . The reference
used shall be indicated: for example, A-weighted sound pressure level,
sound pressure is 20 µPa.
3.2 A-weighted surface sound pressure level, L pA , in decibels: The A-weighted
ace as required in clause 8.
sound pressure level averaged over the measurement su rf
3.3 sound power level, Lw, in decibels: Ten times the logarithm to the base 10 of the
ratio of a given sound power to the reference sound power. The weighting network used
shall be indicated: for example, A-weighted sound power level, WA The reference sound
L .
pW (10A 2W).
power is 1
3.4 measurement surface: A hypothetical su rface of area S enveloping the source on
which the microphone positions are located.
3.5 reference surface: A hypothetical surface which is the smallest rectangular
parallelepiped (i.e., rectangular box) that just encloses the source and terminates on the
reflecting plane.
3.6 measurement distance: The distance between the reference surface and the
measurement su
rface.
3.7 background noise: The A-weighted sound pressure level at each microphone
position with the primary sound source inoperative.

1063 ©IEC
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4 Acoustic environment
4.1
Criteria of adequacy of the test environment
Ideally, the test environment should be free from reflecting objects other than a reflecting
plane so that the source radiates into a free-field over a reflecting plane. Test environ-
ments which are suitable for measurements according to this standard include a flat
outdoor area and a room which meets the qualification requirements of annex A.
Annex A describes procedures for determining the magnitude of the environmental correc-
tion (if any) to account for deviations of the test environment from the ideal conditions.
NOTE - If it is necessary to make measurements in spaces which do not meet the criteria of annex A, the
standard deviation of the test results may be greater than the one given in 1.2.
4.2 Criterion for background noise level
At the microphone positions the A-weighted sound pressure level due to background noise
should be at least 3 dB below the A-weighted sound pressure level with the primary
source operating.
NOTE - When the sound pressure level of the primary source is less than 3 dB above the background
sound pressure level, a valid measurement of the machine under test cannot be made. However, the result
determined with higher background sound level may be useful as an indication of the upper limit of the
sound power level of the source.
4.3 Wind
If measurements are to be made outdoors, the wind speed shall be less than 6 m/s. A
windscreen should be used for wind speeds above 1 m/s to ensure that the level of the
background noise (caused by the cumulative effect of the wind and the other background
noise sources) is at least 3 dB below the level with the source operating.
5 Instrumentation
5.1 General
A sound level meter that meets the requirements of IEC 651 shall be used with the "slow"
time weighting.
To minimize the influence of the observer on the measurements, a cable or an extension
rod should be used bet
...