Acoustics - Determination of sound power levels and sound energy levels of noise sources using sound pressure - Engineering methods for an essentially free field over a reflecting plane (ISO 3744:2010)

ISO 3744:2010 specifies methods for determining the sound power level or sound energy level of a noise source from sound pressure levels measured on a surface enveloping the noise source (machinery or equipment) in an environment that approximates to an acoustic free field near one or more reflecting planes. The sound power level (or, in the case of noise bursts or transient noise emission, the sound energy level) produced by the noise source, in frequency bands or with frequency A-weighting applied, is calculated using those measurements.
The methods specified in ISO 3744:2010 are suitable for all types of noise (steady, non-steady, fluctuating, isolated bursts of sound energy, etc.) defined in ISO 12001.
ISO 3744:2010 is applicable to all types and sizes of noise source (e.g. stationary or slowly moving plant, installation, machine, component or sub-assembly), provided the conditions for the measurements can be met.
The test environments that are applicable for measurements made in accordance with ISO 3744:2010 can be located indoors or outdoors, with one or more sound-reflecting planes present on or near which the noise source under test is mounted. The ideal environment is a completely open space with no bounding or reflecting surfaces other than the reflecting plane(s) (such as that provided by a qualified hemi-anechoic chamber), but procedures are given for applying corrections (within limits that are specified) in the case of environments that are less than ideal.
Information is given on the uncertainty of the sound power levels and sound energy levels determined in accordance with ISO 3744:2010, for measurements made in limited bands of frequency and with frequency A-weighting applied. The uncertainty conforms to ISO 12001:1996, accuracy grade 2 (engineering grade).

Akustik - Bestimmung der Schallleistungs- und Schallenergiepegel von Geräuschquellen aus Schalldruckmessungen - Hüllflächenverfahren der Genauigkeitsklasse 2 für ein im Wesentlichen freies Schallfeld über einer reflektierenden Ebene (ISO 3744:2010)

1.1 Allgemeines
Diese Internationale Norm legt Verfahren für die Bestimmung des Schallleistungs- oder Schallenergiepegels
einer Geräuschquelle aus Schalldruckpegeln fest, die auf einer Fläche gemessen werden, die die
Geräuschquelle (eine Maschine oder ein Gerät) umschließt (Hüllfläche), wobei sich die Geräuschquelle in
einer Umgebung befindet, die angenähert einem akustischen Freifeld in der Nähe einer oder mehrerer
reflektierender Ebenen entspricht. Der von der Geräuschquelle erzeugte Schallleistungspegel (oder Schallenergiepegel
bei Impulsen oder anderen Geräuschen kurzer Dauer) in Frequenzbändern oder mit
A-Bewertung wird aus den Ergebnissen dieser Messungen berechnet.
ANMERKUNG Unterschiedliche Messflächenformen können zu unterschiedlichen Werten des Schallleistungspegels der
betrachteten Geräuschquelle führen. Daher sind in einer

Acoustique - Détermination des niveaux de puissance et d'énergie acoustiques émis par les sources de bruit à partir de la pression acoustique - Méthodes d'expertise pour des conditions approchant celles du champ libre sur plan réfléchissant (ISO 3744:2010)

L'ISO 3744:2010 spécifie des méthodes de détermination du niveau de puissance acoustique ou du niveau d'énergie acoustique émis par une source de bruit à partir des niveaux de pression acoustique mesurés sur une surface entourant la source de bruit (machine ou équipement), dans des conditions approchant celles du champ acoustique libre au voisinage d'un ou de plusieurs plans réfléchissants. Le niveau de puissance acoustique (ou, dans le cas d'impulsions sonores ou d'émissions sonores transitoires, le niveau d'énergie acoustique) produit par la source de bruit, par bandes de fréquences ou avec la pondération A appliquée, est calculé en utilisant ces mesures.
Les méthodes spécifiées dans l'ISO 3744:2010 sont applicables à tous les types de bruit (stable, non stable, fluctuant, impulsions acoustiques isolées, etc.) définis dans l'ISO 12001.
L'ISO 3744:2010 s'applique à tous les types de sources de bruit, quelles que soient leurs dimensions (par exemple installation, dispositif, machine, composant, sous-ensemble fixe ou se déplaçant lentement), sous réserve de pouvoir satisfaire les conditions de mesurage.
Les environnements d'essai qui sont applicables aux mesurages réalisés conformément à l'ISO 3744:2010 peuvent être en salle ou en plein air, comprendre un ou plusieurs plans acoustiques réfléchissants sur lesquels ou à proximité desquels est montée la source de bruit en essai. L'environnement idéal est un espace complètement libre, dépourvu de surfaces limites ou réfléchissantes autres que le ou les plans réfléchissants (tels que ceux d'une salle semi-anéchoïque qualifiée), mais des méthodes sont fournies pour appliquer des corrections (dans des limites spécifiées) lorsque ces environnements ne correspondent pas à ces conditions idéales.
Des informations sont données sur l'incertitude associée aux niveaux de puissance acoustique et aux niveaux d'énergie acoustique déterminés conformément à l'ISO 3744:2010 pour des mesurages effectués dans des bandes de fréquences limitées et avec la pondération fréquentielle A. L'incertitude est conforme à celle de la classe de précision 2 (classe expertise) définie dans l'ISO 12001:1996.

Akustika - Ugotavljanje ravni zvočnih moči virov hrupa z merjenjem zvočnega tlaka - Inženirska metoda v pretežno prostem polju nad odbojno ravnino (ISO 3744:2010)

Ta mednarodni standard določa metode ugotavljanja ravni moči zvoka ali ravni energije zvoka iz virov hrupa iz ravni zvočnega tlaka, merjenih na površju, ki obdaja vir hrupa (stroji ali oprema), v okolju, ki se približuje akustičnemu prostemu polju v bližini ene ali več odbojnih ravnin. Raven moči zvoka (ali v primeru prodorov hrupa ali prehodnih emisij hrupa raven zvočne energije), ki jo proizvede vir hrupa v frekvenčnih pasovih ali z uporabljenim A-uteženjem, je izračunana z uporabo teh merjenj.

General Information

Status
Published
Publication Date
30-Sep-2010
Withdrawal Date
29-Apr-2011
Technical Committee
Drafting Committee
Current Stage
6060 - Definitive text made available (DAV) - Publishing
Start Date
01-Oct-2010
Completion Date
01-Oct-2010

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SLOVENSKI STANDARD
01-december-2010
1DGRPHãþD
SIST EN ISO 3744:2009
$NXVWLND8JRWDYOMDQMHUDYQL]YRþQLKPRþLYLURYKUXSD]PHUMHQMHP]YRþQHJD
WODND,QåHQLUVNDPHWRGDYSUHWHåQRSURVWHPSROMXQDGRGERMQRUDYQLQR ,62

Acoustics - Determination of sound power levels and sound energy levels of noise
sources using sound pressure - Engineering methods for an essentially free field over a
reflecting plane (ISO 3744:2010)
Akustik - Bestimmung der Schallleistungs- und der Schallenergiepegel von
Geräuschquellen aus Schalldruckmessungen - Hüllflächenverfahren der
Genauigkeitsklasse 2 für ein im Wesentlichen freies Schallfeld über einer reflektierenden
Ebene (ISO 3744:2010)
Acoustique - Détermination des niveaux de puissance et d'énergie acoustique émis par
les sources de bruit à partir de la pression acoustique - Méthodes d'expertise pour des
conditions approchant celles du champ libre sur plan réfléchissant (ISO 3744:2010)
Ta slovenski standard je istoveten z: EN ISO 3744:2010
ICS:
17.140.01 $NXVWLþQDPHUMHQMDLQ Acoustic measurements and
EODåHQMHKUXSDQDVSORãQR noise abatement in general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN ISO 3744
NORME EUROPÉENNE
EUROPÄISCHE NORM
October 2010
ICS 17.140.01 Supersedes EN ISO 3744:2009
English Version
Acoustics - Determination of sound power levels and sound
energy levels of noise sources using sound pressure -
Engineering methods for an essentially free field over a
reflecting plane (ISO 3744:2010)
Acoustique - Détermination des niveaux de puissance et Akustik - Bestimmung der Schallleistungs- und der
d'énergie acoustiques émis par les sources de bruit à partir Schallenergiepegel von Geräuschquellen aus
de la pression acoustique - Méthodes d'expertise pour des Schalldruckmessungen - Hüllflächenverfahren der
conditions approchant celles du champ libre sur plan Genauigkeitsklasse 2 für ein im Wesentlichen freies
réfléchissant (ISO 3744:2010) Schallfeld über einer reflektierenden Ebene (ISO
3744:2010)
This European Standard was approved by CEN on 14 August 2010.

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 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 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, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2010 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 3744:2010: E
worldwide for CEN national Members.

Contents Page
Foreword .3
Annex ZA .4

Foreword
The text of ISO 3744:2010 has been prepared by Technical Committee ISO/TC 43 “Acoustics” of the
International Organization for Standardization (ISO) and has been taken over as EN ISO 3744:2010 by
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 April 2011, and conflicting national standards shall be withdrawn at the
latest by April 2011.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 3744:2009.
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.
For relationship with EU Directive, 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, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.
Endorsement notice
The text of ISO 3744:2010 has been approved by CEN as a EN ISO 3744:2010 without any modification.
Annex ZA
(informative)
Relationship between this European Standard and the Essential
Requirements of EU Directive 2006/42/EC

This European Standard has been prepared under a mandate given to CEN by the European Commission
and the European Free Trade Association to provide one means of conforming to Essential Requirements of
the New Approach Directive 2006/42/EC on machinery.
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 confers, within the limits of the scope of this standard, a presumption of conformity
with the relevant Essential Requirements of that Directive and associated EFTA regulations.
WARNING — Other requirements and other EU Directives may be applicable to the products falling
within the scope of this standard.
INTERNATIONAL ISO
STANDARD 3744
Third edition
2010-10-01
Acoustics — Determination of sound
power levels and sound energy levels of
noise sources using sound pressure —
Engineering methods for an essentially
free field over a reflecting plane
Acoustique — Détermination des niveaux de puissance et d'énergie
acoustiques émis par les sources de bruit à partir de la pression
acoustique — Méthodes d'expertise pour des conditions approchant
celles du champ libre sur plan réfléchissant

Reference number
ISO 3744:2010(E)
©
ISO 2010
ISO 3744:2010(E)
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ii © ISO 2010 – All rights reserved

ISO 3744:2010(E)
Contents Page
Foreword .iv
Introduction.v
1 Scope.1
2 Normative references.2
3 Terms and definitions .2
4 Test environment.8
5 Instrumentation .11
6 Definition, location, installation, and operation of noise source under test.12
7 Reference box and measurement surface.14
8 Determination of sound power levels and sound energy levels .18
9 Measurement uncertainty.26
10 Information to be recorded.29
11 Test report.31
Annex A (normative) Qualification procedures for the acoustic environment .32
Annex B (normative) Microphone arrays on a hemispherical measurement surface .37
Annex C (normative) Microphone arrays on a parallelepiped measurement surface .44
Annex D (informative) Microphone arrays on a cylindrical measurement surface.55
Annex E (normative) Calculation of A-weighted sound power levels and A-weighted sound
energy levels from frequency band levels.59
Annex F (normative) Alternative microphone array on a hemispherical measurement surface for
direct measurements of A-weighted sound pressure levels .61
Annex G (normative) Sound power level and sound energy level under reference meteorological
conditions.64
Annex H (informative) Guidelines on the development of information on measurement uncertainty .66
Bibliography.77

ISO 3744:2010(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.
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 3744 was prepared by Technical Committee ISO/TC 43, Acoustics, Subcommittee SC 1, Noise.
This third edition of ISO 3744 cancels and replaces the second edition (ISO 3744:1994) and ISO 4872:1978,
of which it constitutes a merger and a technical revision.
iv © ISO 2010 – All rights reserved

ISO 3744:2010(E)
Introduction
[2] [6]
This International Standard is one of the series ISO 3741 to ISO 3747 , which specify various methods for
determining the sound power levels and sound energy levels of noise sources including machinery, equipment
[1]
and their sub-assemblies. General guidelines to assist in the selection are provided in ISO 3740 . The
selection depends on the environment of the available test facility and on the precision of the sound power
level or sound energy level values required. It may be necess
...

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