EN ISO 3744:2009
(Main)Acoustics - Determination of sound power levels of noise sources using sound pressure - Engineering method in an essentially free field over a reflecting plane (ISO 3744:1994)
Acoustics - Determination of sound power levels of noise sources using sound pressure - Engineering method in an essentially free field over a reflecting plane (ISO 3744:1994)
Establishes definitions, requirements, methods of testing and rated values for phase-to-earth capacitive and screen-to-earth intrusive inductive coupling devices to be used in medium voltage DLC systems.
This publication is of high relevance for Smart Grid.
Akustik - Bestimmung der Schallleistungspegel von Geräuschquellen aus Schalldruckmessungen - Hüllflächenverfahren der Genauigkeitsklasse 2 für ein im Wesentlichen freies Schallfeld über einer reflektierenden Ebene (ISO 3744:1994)
Acoustique - Détermination des niveaux de puissance acoustique émis par les sources de bruit à partir de la pression acoustique - Méthode d'expertise dans des conditions approchant celles du champ libre sur plan réfléchissant (ISO 3744:1994)
Enonce des définitions, des exigences, des méthodes d'essai et des valeurs nominales pour les dispositifs de couplage phase-terre capacitifs et blindage-terre inductifs intrusifs devant être utilisés sur des systèmes DLC moyenne tension.
Akustika - Ugotavljanje ravni zvočnih moči virov hrupa z merjenjem zvočnega tlaka - Inženirska metoda v pretežno prostem polju nad odbojno ravnino (ISO 3744:1994)
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
01-november-2009
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SIST EN ISO 3744:1997
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Acoustics - Determination of sound power levels of noise sources using sound pressure -
Engineering method in an essentially free field over a reflecting plane (ISO 3744:1994)
Akustik - Bestimmung der Schalleistungspegel von Geräuschquellen aus
Schalldruckmessungen - Hüllflächenverfahren der Genauigkeitsklasse 2 für ein im
wesentlichen freies Schallfeld über einer reflektierenden Ebene (ISO 3744:1994)
Acoustique - Détermination des niveaux de puissance acoustique émis par les sources
de bruit à partir de la pression acoustique - Méthode d'expertise dans des conditions
approchant celles du champ libre sur plan réfléchissant (ISO 3744:1994)
Ta slovenski standard je istoveten z: EN ISO 3744:2009
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
July 2009
ICS 17.140.01 Supersedes EN ISO 3744:1995
English Version
Acoustics - Determination of sound power levels of noise
sources using sound pressure - Engineering method in an
essentially free field over a reflecting plane (ISO 3744:1994)
Acoustique - Détermination des niveaux de puissance Akustik - Bestimmung der Schalleistungspegel von
acoustique émis par les sources de bruit à partir de la Geräuschquellen aus Schalldruckmessungen -
pression acoustique - Méthode d'expertise dans des Hüllflächenverfahren der Genauigkeitsklasse 2 für ein im
conditions approchant celles du champ libre sur plan wesentlichen freies Schallfeld über einer reflektierenden
réfléchissant (ISO 3744:1994) Ebene (ISO 3744:1994)
This European Standard was approved by CEN on 13 July 2009.
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, 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
© 2009 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 3744:2009: E
worldwide for CEN national Members.
Contents Page
Foreword .3
Annex ZA (informative) Relationship between this European Standard and the Essential
Requirements of EU Directive 98/37/EC .4
Annex ZB (informative) Relationship between this European Standard and the Essential
Requirements of EU Directive 2006/42/EC .5
Foreword
The text of ISO 3744:1994 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 3744:2009 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 January 2010, and conflicting national standards shall be withdrawn at
the latest by January 2010.
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 3744:1995.
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 EC Directives.
For relationship with EC Directives, see informative Annexes ZA and ZB, which are integral parts 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, 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 3744:1994 has been approved by CEN as a EN ISO 3744:2009 without any modification.
Annex ZA
(informative)
Relationship between this European Standard and the Essential
Requirements of EU Directive 98/37/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 a means of conforming to Essential Requirements of the
New Approach Directive 98/37/EC, amended by 98/79/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 product(s) falling within the
scope of this standard.
Annex ZB
(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 a 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 product(s) falling within
the scope of this standard.
INTERNATIONAL
STANDARD
Second edition
1994-05-O 1
Acoustics - Determination of sound
power levels of noise sources using sound
pressure - Engineering method in an
essentially free field over a reflecting plane
Acoustique - Dgtermination des niveaux de puissance acoustique 6mis
par les sources de bruit P partir de la pression acoustique - M&hode
d’expertise dans des conditions approchant celles du champ libre sur plan
r6fkchissant
Reference number
IS0 3744:1994(E)
IS0 3744:1994(E)
Contents
Page
Scope .
Normative references .
....................................................................................... 3
Definitions
...............................................................
Acoustic environment
......................................................................... 5
Instrumentation
........................ 5
Installation and operation of source under test
................................... 7
Measurement of sound pressure levels
Calculation of surface sound pressure level and sound power
level .
Information to be recorded .
IO Information to be reported . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Annexes
. . . . . . . . 14
A Qualification procedures for the acoustic environment
B Microphone array on the hemispherical measurement surface
C Microphone array on the parallelepiped measurement surface
. . . . . . . . . . . . . . . . . . . .
D Guidelines for the detection of impulsive noise
. . . . . . 30
E Guidelines for the determination of the directivity index
F Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
0 IS0 1994
Ail rights reserved. 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 per-
mission in writing from the publisher.
International Organization for Standardization
Case Postale 56 l CH-1211 Geneve 20 l Switzerland
Printed in Switzerland
ii
IS0 3744:1994(E)
Foreword
IS0 (the International Organization for Standardization) is a worldwide
federation of national standards bodies (IS0 member bodies). The work
of preparing International Standards is normally carried out through IS0
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. IS0
collaborates closely with the International Electrotechnical Commission
(IEC) on all matters of electrotechnical standardization.
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.
International Standard IS0 3744 was prepared by Technical Committee
ISO/TC 43, Acoustics, Sub-Committee SC 1, Noise.
This second edition cancels and replaces the first edition
(IS0 3744: 1981), which has been technically revised.
Annexes A, B and C form an integral part of this International Standard.
Annexes D, E and F are for information only.
IS0 3744:1994(E)
Introduction
0.1 This International Standard is one of the IS0 3740 series, which
specifies various methods for determining the sound power levels of
machines, equipment and their sub-assemblies. When selecting one of
the methods of the IS0 3740 series, 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 IS0 3740. The
IS0 3740 series 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 con-
ditions.
0.2 This International Standard specifies a method for measuring the
sound pressure levels on a measurement surface enveloping the source,
and for calculating the sound power level produced by the source. The
enveloping surface method can be used for any of three grades of accu-
racy (see table O.l), and is used in this International Standard for grade 2
accuracy.
The use of this International Standard requires certain qualification criteria
to be fulfilled , as described in table 0.1. If the relevant qualification criteria
cannot be met, other basic standards with different environmental re-
quirements are suggested (tableO.l; see also IS0 3740 and IS0 9614).
Noise test codes for specific families of machines or equipment should
be based without any contradiction on the requirements of one or more
of the IS0 3740 series or IS0 9614.
Free-field conditions are usually not encountered in typical machine rooms
where sources are normally installed. If measurements are made in such
installations, corrections may be required to account for background noise
or undesired reflections.
The methods specified in this International Standard permit the determi-
nation of sound power level both as an A-weighted value and in frequency
bands.
The A-weighted value calculated fro m frequency band data may differ
from that determ ined f ram measu red A-weighted sound press ure levels.
0.3 In this International Standard, the computation of sound power level
from sound pressure level measurements is based on the premise that the
sound power output of the source is directly proportional to the mean-
square sound pressure averaged over time and space.
IS0 3744: 1994(E)
A. d.
I a1318 u.1 - uvervlew or InternatIonal StatWards tor determlnatlon
of sound power levels of noise sources using enveloping surface
methods over a reflecting plane
...
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