ISO 16032:2004

INTERNATIONAL ISO
STANDARD 16032
First edition
2004-09-15
Acoustics — Measurement of sound
pressure level from service equipment in
buildings — Engineering method
Acoustique — Mesurage du niveau de pression acoustique des
équipements techniques dans les bâtiments — Méthode d'expertise

Reference number
©
ISO 2004
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but
shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In
downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat
accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation
parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In
the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.

©  ISO 2004
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or
ISO's member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2004 – All rights reserved

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 16032 was prepared by the European Committee for Standardization (CEN) in collaboration with
Technical Committee ISO/TC 43, Acoustics, Subcommittee SC 2, Building acoustics, in accordance with the
Agreement on technical cooperation between ISO and CEN (Vienna Agreement).
Throughout the text of this document, read “.this European Standard.” to mean “.this International
Standard.”.
Contents page
Foreword.v
Introduction .vi
1 Scope .1
2 Normative references .1
3 Terms and definitions .1
4 Instrumentation.4
5 Test method – General .5
6 Measurement procedure.6
7 Measurement of reverberation time.8
8 Correction for background noise.8
9 Precision.9
10 Test report .9
Annex A (normative) A-weighting and C-weighting correction value.11
Annex B (normative) Operating conditions and operating cycles for measuring the maximum sound
pressure level and the equivalent continuous sound pressure level .12
Bibliography .19
iv © ISO 2004 – All rights reserved

Foreword
This document (EN ISO 16032:2004) has been prepared by Technical Committee CEN/TC 126 “Acoustic
properties of building products and of buildings”, the secretariat of which is held by AFNOR, in collaboration with
Technical Committee ISO/TC 43 “Acoustics”.
This European Standard shall be given the status of a national standard, either by publication of an identical text or
by endorsement, at the latest by March 2005, and conflicting national standards shall be withdrawn at the latest by
March 2005.
This document includes a Bibliography.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark,
Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
Introduction
This document specifies the engineering method for the measurement of sound pressure level from service
equipment in buildings. For use of this document measurements are performed under specified operation
conditions and operating cycles. Such conditions are given in Annex B.
The operating conditions and operating cycles given in Annex B are only used if they are not opposed to national
requirements and regulations.
vi © ISO 2004 – All rights reserved

1 Scope
This document specifies methods for measuring the sound pressure level from service equipment in buildings
installed to building structures. This document covers specifically measurements of sanitary installations,
mechanical ventilation, heating and cooling service equipment, lifts, rubbish chutes, boilers, blowers, pumps and
other auxiliary service equipment, and motor driven car park doors, but can also be applied to other equipment
attached to or installed in buildings.
The methods are suitable for rooms with volumes of approximately 300 m or less in e.g. dwellings, hotels, schools,
offices and hospitals. The standard is not in general intended for measurements in large auditoria and concert halls.
However, the operating conditions and operating cycles in Annex B can be used in such cases.
The service equipment sound pressure level is determined as the maximum A- weighted and optionally C- weighted
sound pressure level occurring during a specified operation cycle of the service equipment under test, or as the
equivalent continuous sound pressure level determined with a specified integration time. A-weighted and
C- weighted values are calculated from octave-band measurements.
2 Normative references
The following referenced documents are indispensable for the application 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.
EN 60942, Electroacoustics — Sound calibrators (IEC 60942:2003).
EN 61260, Electroacoustics — Octave-band and fractional-octave-band filters (IEC 61260:1995).
EN 61672-1, Electroacoustics - Sound level meters - Part 1: Specifications (IEC 61672-1:2002).
EN 61672-2, Electroacoustics - Sound level meters - Part 2: Pattern evaluation tests (IEC 61672-2:2003).
EN ISO 3382, Acoustics - Measurement of the reverberation time of rooms with reference to other acoustical
parameters (ISO 3382:1997).
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
sound pressure level
L
ten times the logarithm to the base 10 of the ratio of the square of the sound pressure, p (t), to the square of the
reference sound pressure p , measured with a particular time weighting and a particular frequency weighting,
selected from those defined in EN 61672-1. It is expressed in decibels. The reference sound pressure is 20 µPa
3.2
average sound pressure level
L
n
 
0,1×L
i
 10 
∑
 i=1 
= 10 lg dB (1)
L
 
n
 
 
where
L is the sound pressure level at different microphone positions, in decibels, to be averaged
i
3.3
A- weighted sound pressure level calculated from octave-band values in the frequency range 63 Hz to
8 000 Hz
L
A
n
0,1( + )
Li Ai
= 10 lg  dB (2)
LA 10
∑
i=1
where
L is the sound pressure level in octave-band i, and A is the A-weighting correction for octave-band i
i i
(see Annex A). The value of L depends on the measurements, but can be all the parameters of 3.6
i
3.4
C- weighted sound pressure level calculated from octave-band values in the frequency range 31,5 Hz to
8 000 Hz
L
C
n
0,1( + )
Li Ci
= 10 lg  dB (3)
L 10
C
∑
i=1
where
L is the sound pressure level in octave-band i, and C is the C-weighting correction for octave-band i
i i
(see Annex A). The value of L depends on the measurements, but can be all the parameters of 3.6
i
2 © ISO 2004 – All rights reserved

3.5
sound exposure level
L
E
the sound exposure level of a sound event is given by the formula:
t
1 p (t)
= 10 lg  dt dB (4)
L
E
∫
t p
o
t
o
where
p(t) is the instantaneous sound pressure in Pascals;
t - t is a stated time interval long enough to encompass all significant sound of a stated event, in
2 1
seconds;
p is the reference sound pressure (20 µPa);
o
t is the reference duration (t = 1 s)
o o
3.6
service equipment sound pressure level in octave-bands in the frequency range 31,5 Hz to 8 000 Hz
in the following subclauses 3.6.1 to 3.6.9 are defined the octave-band values which can be measured according to
this document. See also Clause 5, Table 1
3.6.1
L
S max
maximum sound pressure level in octave-bands determined with time weighting “S”
3.6.2
L
S max, nT
maximum sound pressure level in octave-bands determined with time weighting “S” and standardized to a
reverberation time of 0,5 s (3.8, equation (5))
3.6.3
L
S max, n
maximum sound pressure level in octave-bands determined with time weighting “S” and normalized to an
equivalent sound absorption area of 10 m (3.8, equation (6))
3.6.4
L
F max
maximum sound pressure level in octave-bands determined with time weighting “F”
3.6.5
L
F max, nT
maximum sound pressure level in octave-bands determined with time weighting “F” and standardized to a
reverberation time of 0,5 s (3.8, equation (5))
3.6.6
L
F max, n
maximum sound pressure level in octave-bands determined with time weighting “F” and normalized to an
equivalent sound absorption area of 10 m (3.8, equation (6))
3.6.7
L
eq
equivalent continuous sound pressure level in octave-bands
3.6.8
L
eq, nT
equivalent continuous sound pressure level in octave-bands standardized to a reverberation time of 0,5 s (3.8,
equation (5))
3.6.9
L
eq, n
equivalent continuous sound pressure level in octave-bands normalized to an equivalent sound absorption area of
10 m (3.8, equation (6))
3.7
reverberation time
T
time that would be required for the sound pressure level to decrease by 60 dB after the sound source has stopped.
It is expressed in seconds
3.8
standardized/normalized sound pressure level
the measured sound pressure levels in octave-bands can be standardized to a reverberation time of 0,5 s or
normalized to an equivalent sound absorption area of 10 m . The equations (5) and (6), respectively, are used
T
= L - 10 lg dB (5)
L
nT
T
where
L can be L , L , L ;
S max F max eq
T is the measured reverberation time in seconds;
T = 0,5 s
T
A0
= L - 10 lg (6)
L
n
0,16 V
where
L can be L , L , L ;
S max F max eq
T is the measured reverberation time in seconds;
V is the room volume in cubic metres;
A is the reference equivalent sound absorption area in square metres; A = 10 m
0 0
 
s
 
0,16 has the unit .
m
 
 
4 Instrumentation
Measurement of the maximum sound pressure level according to this document implies the use of an octave-band
real-time frequency analyser. The analyser shall be able to read values of all octave-band sound pressure levels at
the time when the maximum A-weighted or C-weighted sound pressure level occurs (during a specified operating
cycle of the service equipment under test).
4 © ISO 2004 – All rights reserved

NOTE It is important to ensure that the equipment used according to this document fulfils the requirement stated above.
The most common analysers used for building acoustic measurements include this feature.
The instrumentation system, including the microphone and cable, shall meet the requirements for a class 1
instrument specified in EN 61672-1.
For measurements in octave-bands, the filters shall meet the requirements for class 1 filters specified in EN 61260.
At the beginning and at the end of the measurements verify the sensitivity of the instrumentation with a sound
calibrator class 1 according to EN 60942.
5 Test method – General
The service equipment sound pressure level is measured in octave-bands in the frequency range 31,5 Hz/63 Hz to
8 000 Hz as the linear (unweighted) spectrum corresponding to the maximum A-weighted or C-weighted sound
pressure level occurring during a specified operating cycle of the service equipment under test. In order to measure
the service equipment sound pressure level a parallel time dependent recording of the A-weighted or C-weighted
sound pressure level and the sound pressure levels in octave-bands shall be made (multispectral recording). For
evaluation of the equipment sound pressure level take the octave band spectrum at that time when the maximum
A-weighted or C-weighted sound pressure level occurs. Time weighting “S” or “F” shall be used. Alternatively or
additionally the equivalent continuous sound pressure level can be determined with a specified integration time.
The octave-band results are corrected for background noise and - if required - standardized to a reverberation time
of 0,5 s or normalized to an equivalent sound absorption area of 10 m . Finally the A-weighted and C-weighted
sound pressure levels are calculated from the corrected octave-band results.
A-weighted and C-weighted values shall always be calculated from octave-band results, also in situations where
standardization or normalization is not carried out.
The single number quantities which can be determined according to this document are given in Table 1 (calculated
from the octave-band values defined in 3.6.1 to 3.6.9). The notation in the table shall be used when reporting
measurement results. The different quantities can be combined according to e.g. requirements in national building
code regulations.
Table 1 — Single number quantities
A-weighted value C-weighted value
(calculated from (calculated from
octave-band values octave-band values
in the frequency in the frequency
range 63 Hz to range 31,5 Hz to
8 000 Hz) 8 000 Hz)
L L
Maximum sound pressure level, time
AS max CS max
a
L
weighting “S”
L
AS max, nT
CS max, nT
a
L
L
AS max, n
CS max, n
Maximum sound pressure level, time L L
AF max CF max
a
weighting “F” L
L
AF max, nT
CF max, nT
a
L
L
AF max, n
CF max, n
L L
Equivalent continuous sound pressure
Aeq ceq
a
L
level
L
Aeq, nT
Ceq, nT
a
L
L
Aeq, n
Ceq, n
a
See 6.7.
The different single number quantities given in Table 1 are not comparable. Only measurement results obtained
with the same method shall be compared. When measurement results are compared with legal requirements it
shall be ensured that both refer to the same quantity.
If the sound contains clearly audible tonal components, this shall be stated in the report.
Windows and doors shall be closed during the measurements. The person performing the test should stay outside
the room.
6 Measurement procedure
6.1 General
The service equipment sound pressure level is to be determined for a specified operating condition and operating
cycle. Operating conditions and operating cycles are given in Annex B. They shall only be used if they are not
opposed to national requirements and regulations.
According to this document the sound pressure level is measured in three microphone positions, one position in a
corner of the room and two positions in the reverberant sound field.
The service equipment sound pressure level is measured using the following procedure (step 6.2 to 6.9):
6.2 Selection of the corner position for the microphone
To select the corner position (position no. 1), search for the corner of the room with the highest C-weighted sound
pressure level. The measurement shall be carried out as the maximum sound pressure level with time weighting “S”
or “F”, or as the equivalent continuous sound pressure level. The quantity used for selection of the corner position
shall be the same as the one chosen to be the final result, but without any corrections. Use the chosen operating
condition and operating cycle.
The microphone position shall, preferably, at each corner be 0,5 m from the walls and 0,5 m above the floor. If in a
corner this is not feasible due to protruding furniture, obstacles etc., increase the height to 1,0 m or if necessary to
6 © ISO 2004 – All rights reserved

1,5 m above the floor. The measurement height shall be the same for all the corners. Move away small protruding
items that do not affect the sound field, if necessary. The microphone position shall be at least 0,2 m away from
any obstacle. If the sound pressure level in a corner is dominated by direct sound from a source in the room - e.g. a
ventilation outlet - this corner shall be left out when choosing the corner position.
For selection of the corner position, the C-weighted equivalent continuous sound pressure level can be measured
directly e.g. by use of a hand held integrating sound level meter. Calculation from octave-bands is not required. The
selection procedure for the corner position stated above shall be used prior to all measurements according to this
document.
6.3 Selection of the reverberant field positions of the microphone
Choose two additional positions (nos. 2 and 3) in the reverberant field of the room. Whenever practicable, the
minimum distance between each of the positions 1 (the corner position), 2 and 3 shall be at least 1,5 m. The
distance to any sound source in the room shall be at least 1,5 m. The distance between positions 2 and 3 and any
room surface shall be at least 0,75 m. In small rooms where this requirement cannot be fulfilled, the distance can
be decreased to 0,5 m. The height above floor level shall be at least 0,5 m and not more than 1,5 m.
6.4 Determination of the number of measurements at each microphone position
6.4.1 For measurement of the equivalent continuous sound pressure level
In the corner position, make two consecutive measurements of the A-weighted equivalent continuous sound
pressure level L . For this purpose the chosen operating conditions and operating cycles shall be used (as for
Aeq
choosing the corner position in 6.2, a hand held integrating sound level meter can be used). If the difference
between the results of the two consecutive measurements is equal to or less than 1,0 dB, then one measurement
in each of the microphone positions 1, 2 and 3 is sufficient. If the difference exceeds 1,0 dB, the number of
measurements at each microphone position shall be equal to the difference in level (rounded up to nearest whole
value; a difference of e.g. 3 dB results in three measurements in each position).
6.4.2 For measurement of the maximum sound pressure level
If the maximum sound pressure levels are to be measured, use the A-weighted maximum sound pressure level with
a similar procedure to 6.4.1 to determine the number of measurements to be made at each position. The chosen
operating conditions and operating cycles shall be used. However, especially for sound events of short duration, it
is allowed to use the sound exposure level L instead of the maximum sound pressure level when determining the
AE
required number of measurements at each microphone position.
6.5 Averaging the sound pressure level
Use the relevant operating conditions and operating cycles as stated in Annex B. Measure the linear (unweighted)
octave-band levels at each of the three microphone positions the number of times determined according to 6.4.
Calculate for each octave-band the average level of all the measurements (see 3.2). The octave-band levels shall
be rounded to one decimal place.
6.6 Correction for background noise
Determine the octave-band background noise level and correct the measured service equipment sound pressure
level according to Clause 8.
6.7 Standardization or normalization of octave band results
If required, the octave-band results corrected for background noise can be standardized or normalized to reference
absorption properties of the room. Measure the reverberation time according to Clause 7, and make the
standardization by
...