SIST EN ISO 3743-2:2019

SLOVENSKI STANDARD
SIST EN ISO 3743-2:2019
01-december-2019
Nadomešča:
SIST EN ISO 3743-2:2009
Akustika - Ugotavljanje ravni zvočnih moči virov hrupa z merjenjem zvočnega
tlaka - Inženirske metode za majhne premične vire v odmevnih poljih - 2. del:
Metode za posebne odmevnice (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 3743-2:2018)
Akustik - Bestimmung der Schallleistungspegel von Geräuschquellen aus
Schalldruckmessungen - Verfahren der Genauigkeitsklasse 2 für kleine, transportable
Quellen in Hallfeldern - Teil 2: Verfahren für Sonder-Hallräume (ISO 3743-2:2018)
Acoustique - Détermination des niveaux de puissance acoustique émis par les sources
de bruit à partir de la pression acoustique - Méthodes d'expertise en champ réverbéré
applicables aux petites sources transportables - Partie 2: Méthodes en salle d'essai
réverbérante spéciale (ISO 3743-2:2018)
Ta slovenski standard je istoveten z: EN ISO 3743-2:2019
ICS:
17.140.01 Akustična merjenja in Acoustic measurements and
blaženje hrupa na splošno noise abatement in general
SIST EN ISO 3743-2:2019 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN ISO 3743-2:2019

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SIST EN ISO 3743-2:2019


EN ISO 3743-2
EUROPEAN STANDARD

NORME EUROPÉENNE

September 2019
EUROPÄISCHE NORM
ICS 17.140.01 Supersedes EN ISO 3743-2:2009
English Version

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 3743-
2:2018)
Acoustique - Détermination des niveaux de puissance Akustik - Bestimmung der Schallleistungspegel von
acoustique émis par les sources de bruit à partir de la Geräuschquellen aus Schalldruckmessungen -
pression acoustique - Méthodes d'expertise en champ Verfahren der Genauigkeitsklasse 2 für kleine,
réverbéré applicables aux petites sources transportable Quellen in Hallfeldern - Teil 2: Verfahren
transportables - Partie 2: Méthodes en salle d'essai für Sonder-Hallräume (ISO 3743-2:2018)
réverbérante spéciale (ISO 3743-2:2018)
This European Standard was approved by CEN on 29 January 2018.

CEN 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 CEN
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 CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.





EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2019 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 3743-2:2019 E
worldwide for CEN national Members.

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SIST EN ISO 3743-2:2019
EN ISO 3743-2:2019 (E)
Contents Page
European foreword . 3
Annex ZA (informative) Relationship between this European Standard and the essential
requirements of Directive 2006/42/EC aimed to be covered . 4

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SIST EN ISO 3743-2:2019
EN ISO 3743-2:2019 (E)
European foreword
This document (EN ISO 3743-2:2019) has been prepared by Technical Committee ISO/TC 43
"Acoustics" in collaboration with Technical Committee CEN/TC 211 “Acoustics” the secretariat of which
is held by DIN.
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 2020, and conflicting national standards shall
be withdrawn at the latest by March 2020.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 3743-2:2009.
This document has been prepared under a mandate given to CEN by the European Commission and the
European Free Trade Association, and supports essential requirements of EU Directive(s).
For the relationship with EU Directive(s) see informative Annex ZA, which is an integral part of this
document.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the
United Kingdom.
Endorsement notice
The text of ISO 3743-2:2018 has been approved by CEN as EN ISO 3743-2:2019 without any
modification.

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SIST EN ISO 3743-2:2019
EN ISO 3743-2:2019 (E)
Annex ZA
(informative)

Relationship between this European Standard and the essential
requirements of Directive 2006/42/EC aimed to be covered
This European Standard has been prepared under a Commission’s standardization request M/396
(Machinery) to provide one voluntary means of conforming to essential requirements of Directive
2006/42/EC of the European Parliament and of the Council of 17 May 2006 on machinery, and
amending Directive 95/16/EC (recast).
Once this standard is cited in the Official Journal of the European Union under that Directive,
compliance with the normative clauses of this standard given in Table ZA.1 confers, within the limits of
the scope of this standard, a presumption of conformity with the corresponding essential requirements
of that Directive, and associated EFTA regulations.
Table ZA.1 — Correspondence between this European Standard and Directive 2006/42/EC
Essential Requirements of Clause(s)/sub-clause(s) of this EN Remarks/Notes
Directive
1.7.4.2 u) Clauses 5 to 13, Annexes A, E and F
WARNING 1 — Presumption of conformity stays valid only as long as a reference to this European
Standard is maintained in the list published in the Official Journal of the European Union. Users of this
standard should consult frequently the latest list published in the Official Journal of the European
Union.
WARNING 2 — Other Union legislation may be applicable to the product(s) falling within the scope of
this standard.
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SIST EN ISO 3743-2:2019
INTERNATIONAL ISO
STANDARD 3743-2
Second edition
2018-02
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
Acoustique — Détermination des niveaux de puissance acoustique
émis par les sources de bruit à partir de la pression acoustique —
Méthodes d'expertise en champ réverbéré applicables aux petites
sources transportables —
Partie 2: Méthodes en salle d'essai réverbérante spéciale
Reference number
ISO 3743-2:2018(E)
©
ISO 2018

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SIST EN ISO 3743-2:2019
ISO 3743-2:2018(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2018
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2018 – All rights reserved

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SIST EN ISO 3743-2:2019
ISO 3743-2:2018(E)

Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
5 Noise source . 2
6 Requirements for special reverberation test room . 2
6.1 General . 2
6.2 Volume of test room. 2
6.3 Reverberation time of test room. 3
6.4 Surface treatment . 3
6.5 Criterion for background noise. 3
6.6 Criteria for temperature and humidity . 4
6.7 Evaluation of suitability of test room . 4
7 Instrumentation . 5
7.1 General . 5
7.2 Microphone and its associated cable . 5
7.3 Amplifier and weighting network . 5
7.4 Octave-band filters . 6
7.5 Squaring and averaging circuits and indicating device . 6
7.6 Frequency response of the instrumentation system . 6
7.7 Calibration . 6
8 Installation and operation of source under test . 6
8.1 General . 6
8.2 Source location . 6
8.3 Source mounting . 7
8.4 Auxiliary equipment . 7
8.5 Operation of source during the test . 7
9 Measurements in test room . 8
9.1 General . 8
9.2 Period of observation . 8
9.3 Microphone positions . 8
9.4 Number of microphones and source positions . 8
9.5 Criteria for the presence of spectral irregularities .10
9.6 Averaging technique with moving microphones .10
9.6.1 General.10
9.6.2 Path length for continuous averaging .10
9.6.3 Location of path within test room .10
9.6.4 Speed of traverse .10
9.7 Array of fixed microphones .11
9.8 Correction for background sound pressure levels .11
10 Calculation of sound power levels .11
10.1 Calculation of mean band pressure levels .11
10.2 Direct method for determining sound power levels .12
10.3 Comparison method for determining band power levels .12
10.4 A-weighted sound power levels determined by the comparison method .13
11 Measurement uncertainty .13
11.1 Methodology .13
11.2 Determination of σ .14
omc
© ISO 2018 – All rights reserved iii

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SIST EN ISO 3743-2:2019
ISO 3743-2:2018(E)

11.3 Determination of σ .14
R0
11.3.1 General.14
11.3.2 Round robin test .14
11.3.3 Modelling approach for σ .15
R0
11.4 Typical upper bound values of σ .15
R0
11.5 Total standard deviation σ and expanded uncertainty U .16
tot
12 Information to be recorded .16
12.1 General .16
12.2 Sound source under test .16
12.3 Acoustical environment .17
12.4 Instrumentation .17
12.5 Acoustical data .17
13 Information to be reported .17
Annex A (normative) Characteristics and calibration of reference sound source .18
Annex B (informative) Guidelines for the design of special reverberation test rooms .19
Annex C (informative) Examples of suitable instrumentation systems .24
Annex D (informative) Guidance on the development of information on
measurement uncertainty .26
Annex E (normative) Sound power level under reference meteorological conditions .36
Annex F (normative) Calculation of A-weighted sound power levels from octave band levels .37
Bibliography .38
iv © ISO 2018 – All rights reserved

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SIST EN ISO 3743-2:2019
ISO 3743-2:2018(E)

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.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
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. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following
URL: www .iso .org/ iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 43, Acoustics, Subcommittee SC 1, Noise.
This second edition cancels and replaces the first edition (ISO 3743-2:1994), of which it constitutes a
minor revision. The main changes are the following:
— Table 0.1 in the Introduction deleted;
— restructuring of the content of Clause 1;
— references updated;
— clause on measurement uncertainty revised to be in-line with the other standards of the ISO 3740
series (now Clause 11);
— new Annexes D, E, and F added;
— new entries in Bibliography added.
A list of all the parts in the ISO 3743 series can be found on the ISO website.
© ISO 2018 – All rights reserved v

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SIST EN ISO 3743-2:2019
ISO 3743-2:2018(E)

Introduction
ISO 3743 is one standard of the series ISO 3741 to ISO 3747 series, which specifies various methods for
determining the sound power levels of machines, equipment and sub-assemblies. These basic standards
specify the acoustical requirements for measurements appropriate for different test environments.
When selecting one of the methods of the series ISO 3741 to ISO 3747, it is necessary to select the most
appropriate for the conditions and purposes of the noise test. General guidelines to assist in the selection
are provided in ISO 3740. The series ISO 3741 to ISO 3747 gives only general principles regarding the
operating and mounting conditions of the machine or equipment under test. Reference should be made
to the noise test code for a specific type of machine or equipment, if available, for specifications on
mounting and operating conditions.
The method given in this document enables measurement of sound pressure levels with A-weighting
and in octave bands at pre-scribed fixed microphone positions or along prescribed paths. It allows
determination of A-weighted sound power levels or sound power levels with other weighting and octave-
band sound power levels. Quantities which cannot be determined are the directivity characteristics of
the source and the temporal pattern of noise radiated by sources emitting non-steady noise.
ISO 3743-1 and this document specify engineering methods for determining the A-weighted and octave-
band sound power levels of small noise sources. The methods are applicable to small machines, devices,
components and sub-assemblies which can be installed in a special reverberation test room or in a hard-
walled test room with prescribed acoustical characteristics. The methods are particularly suitable for
small items of portable equipment; they are not intended for larger pieces of stationary equipment
which, due to their manner of operation or installation, cannot readily be moved into the test room and
operated as in normal usage. The procedures are intended to be used when an engineering grade of
accuracy is desired without requiring the use of laboratory facilities.
In ISO 3743-1, a comparison method is used to determine the octave-band sound power levels of the
source. The spatial average (octave-band) sound pressure levels produced by the source under test are
compared to the spatial average (octave-band) sound pressure levels produced by a reference sound
source of known sound power output. The difference in sound pressure levels is equal to the difference
in sound power levels if conditions are the same for both sets of measurements. The A-weighted sound
power level is then calculated from the octave-band sound power levels.
The requirements to be fulfilled by the special reverberation test room for measurements in accordance
with this document are significantly more restrictive than those placed on the hard-walled test room
by the comparison method of ISO 3743-1.
vi © ISO 2018 – All rights reserved

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SIST EN ISO 3743-2:2019
INTERNATIONAL STANDARD ISO 3743-2:2018(E)
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
1 Scope
This document specifies a relatively simple engineering method for determining the sound power levels
of small, movable noise sources. The methods specified in this document are suitable for measurements
of all types of noise within a specified frequency range, except impulsive noise consisting of isolated
bursts of sound energy which are covered by ISO 3744 and ISO 3745.
NOTE A classification of different types of noise is given in ISO 12001.
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.
ISO 3741, Acoustics — Determination of sound power levels and sound energy levels of noise sources using
sound pressure — Precision methods for reverberation test rooms
ISO 3743-1, Acoustics — Determination of sound 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 3745, Acoustics — Determination of sound power levels and sound energy levels of noise sources using
...