EN ISO 3745:2003

SLOVENSKI STANDARD
01-september-2004
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Acoustics - Determination of sound power levels of noise sources using sound pressure -
Precision methods for anechoic and semi-anechoic rooms (ISO 3745:2003)
Akustik - Bestimmung der Schallleistungspegel von Geräuschquellen aus
Schalldruckmessungen - Verfahren der Genauigkeitsklasse 1 für reflexionsarme Räume
und Halbräume (ISO 3745:2003)
Acoustique - Détermination des niveaux de puissance acoustique émis par les sources
de bruit a partir de la pression acoustique - Méthodes de laboratoire pour les salles
anéchoiques et semi-anéchoiques (ISO 3745:2003)
Ta slovenski standard je istoveten z: EN ISO 3745:2003
ICS:
17.140.01 $NXVWLþQDPHUMHQMDLQ Acoustic measurements and
EODåHQMHKUXSDQDVSORãQR noise abatement in general
91.120.20 $NXVWLNDYVWDYEDK=YRþQD Acoustics in building. Sound
L]RODFLMD insulation
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN ISO 3745
NORME EUROPÉENNE
EUROPÄISCHE NORM
December 2003
ICS 17.140.01
English version
Acoustics - Determination of sound power levels of noise
sources using sound pressure - Precision methods for anechoic
and hemi-anechoic rooms (ISO 3745:2003)
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 - Verfahren
pression acoustique - Méthodes de laboratoire pour les der Genauigkeitsklasse 1 für reflexionsarme Räume und
salles anéchoïques et semi-anéchoïques (ISO 3745:2003) Halbräume (ISO 3745:2003)
This European Standard was approved by CEN on 3 November 2003.
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 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 Management Centre has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,
Hungary, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Slovakia, Spain, Sweden, Switzerland and United
Kingdom.
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COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2003 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 3745:2003 E
worldwide for CEN national Members.

CORRECTED  2004-03-03
Foreword
This document (EN ISO 3745:2003) 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 DS.
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 June 2004, and conflicting national
standards shall be withdrawn at the latest by June 2004.
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 relationship with EU Directive(s), see informative Annex ZB, 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, Czech
Republic, Denmark, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy,
Luxembourg, Malta, Netherlands, Norway, Portugal, Slovakia, Spain, Sweden, Switzerland and
the United Kingdom.
Endorsement notice
The text of ISO 3745:2003 has been approved by CEN as EN ISO 3745:2003 without any
modifications.
NOTE Normative references to International Standards are listed in Annex ZA (normative).
Annex ZA
(normative)
Normative references to international publications
with their relevant European publications
This European Standard incorporates by dated or undated reference, provisions from other
publications. These normative references are cited at the appropriate places in the text and the
publications are listed hereafter. For dated references, subsequent amendments to or revisions of
any of these publications apply to this European Standard only when incorporated in it by
amendment or revision. For undated references the latest edition of the publication referred to
applies (including amendments).
NOTE Where an International Publication has been modified by common modifications, indicated
by (mod.), the relevant EN/HD applies.
Publication Year Title EN Year
ISO 7574-1 1985 Acoustics - Statistical methods for EN 27574-1 1988
determining and verifying stated
noise emission values of machinery
and equipment - Part 1: General
considerations and definitions
ISO 7574-4 1985 Acoustics - Statistical methods for EN 27574-4 1988
determining and verifying stated
noise emission values of machinery
and equipment - Part 4: Methods
for stated values for batches of
machines
ANNEX ZB
(informative)
Relationship between this European Standard and the Essential
Requirements of EU Directive 98/37 EEC
This European Standard has been prepared under a mandate given to CEN by the European

Commission and the European Free Trade Association to provide a means of conforming to
Essential Requirements of the New Approach Directive 98/37 EEC.
Once this standard is cited in the Official Journal of the European Communities under that
Directive and has been implemented as a national standard in at least one Member State,
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.
WARNING: Other requirements and other EU Directives may be applicable to the product(s)
falling within the scope of this standard.
INTERNATIONAL ISO
STANDARD 3745
Second edition
2003-12-01
Acoustics — Determination of sound
power levels of noise sources using
sound pressure — Precision methods for
anechoic and hemi-anechoic rooms
Acoustique — Détermination des niveaux de puissance acoustique
émis par les sources de bruit à partir de la pression acoustique —
Méthodes de laboratoire pour les salles anéchoïques et semi-
anéchoïques
Reference number
ISO 3745:2003(E)
©
ISO 2003
ISO 3745:2003(E)
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ISO 3745:2003(E)
Contents Page
Foreword. v
Introduction . vi
1 Scope. 1
2 Normative references . 1
3 Terms and definitions. 2
4 Measurement uncertainty. 5
5 Test room requirements. 6
5.1 General. 6
5.2 Criterion for adequacy of the test room . 7
5.3 Criterion for background noise . 7
5.4 Criterion for temperature. 7
5.5 Humidity correction . 7
6 Instrumentation . 7
6.1 General. 7
6.2 Calibration. 8
7 Installation and operation of source under test.8
7.1 General. 8
7.2 Source location . 8
7.3 Source mounting. 8
7.4 Auxiliary equipment. 9
7.5 Operation of source under test . 9
8 Measurement of sound pressure levels for the determination of sound power level . 10
8.1 General. 10
8.2 Measurement surface . 10
8.3 Microphone positions. 11
8.4 Conditions of measurement. 12
8.5 Data to be obtained. 13
8.6 Correction for background sound pressure levels . 13
8.7 Calculation of surface sound pressure level . 14
9 Measurement of single-event sound pressure levels for the determination of sound
energy level . 15
10 Calculation of sound power level and sound energy level. 16
10.1 Sound power level . 16
10.2 Sound energy level . 17
11 Information to be recorded . 17
11.1 General. 17
11.2 Sound source under test. 18
11.3 Acoustic environment . 18
11.4 Instrumentation .
...