SIST EN ISO 3746:2009

SLOVENSKI STANDARD
01-november-2009
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SIST EN ISO 3746:1997
SIST EN ISO 3746:1997/AC1:1997
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Acoustics - Determination of sound power levels of noise sources using sound pressure -
Survey method using an enveloping measurement surface over a reflecting plane (ISO
3746:1995, including Cor 1:1995)
Akustik - Bestimmung der Schalleistungspegel von Geräuschquellen aus
Schalldruckmessungen - Hüllflächenverfahren der Genauigkeitsklasse 3 über einer
reflektierenden Ebene (ISO 3746:1995, einschließlich Cor 1:1995)
Acoustique - Détermination des niveaux de puissance acoustique émis par les sources
de bruit à partir de la pression acoustique - Méthode de contrôle employant une surface
de mesure enveloppante au-dessus d'un plan réfléchissant (ISO 3746:1995, Cor 1:1995
inclus)
Ta slovenski standard je istoveten z: EN ISO 3746:2009
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 3746
NORME EUROPÉENNE
EUROPÄISCHE NORM
July 2009
ICS 17.140.01 Supersedes EN ISO 3746:1995
English Version
Acoustics - Determination of sound power levels of noise
sources using sound pressure - Survey method using an
enveloping measurement surface over a reflecting plane (ISO
3746:1995, including Cor 1:1995)
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 de contrôle employant une Hüllflächenverfahren der Genauigkeitsklasse 3 über einer
surface de mesure enveloppante au-dessus d'un plan reflektierenden Ebene (ISO 3746:1995, einschließlich Cor
réfléchissant (ISO 3746:1995, Cor 1:1995 inclus) 1:1995)
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 3746:2009: 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 3746:1995, including Cor 1:1995 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
3746:2009 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 3746:1995.
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 3746:1995, including Cor 1:1995 has been approved by CEN as a EN ISO 3746:2009 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
1995-08-I 5
Acoustics - Determination of sound
power levels of noise sources using sound
pressure - Survey method using an
enveloping measurement surface over a
reflecting plane
- Dgtermination des niveaux de puissance acoustique 6mis
Acoustique
par /es sources de bruit ;i paflir de la pression acoustique - Mkthode de
contr6le employant une surface de mesure enveloppante au-dessus d’un
plan r6fkhissant
Reference number
IS0 3746: 1995(E)
IS0 3746: 1995(E)
Contents
Page
.............................................................................................. 1
1 Scope
..................................................................... 3
2 Normative references
3 Definitions .
4 Acoustic environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5 Instrumentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6 Installation and operation of source under test . . . . . . . . . . . . . . . . . . . . . . . .
7 Measurement of sound pressure levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8 Calculation of A-weighted surface sound pressure level and
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A-weighted sound power level
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
9 Information to be recorded
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
10 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
. . . . . . . . . . . . . . . . . . . . 26
D Guidelines for the detection of impulsive noise
E Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
0 IS0 1995
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 the publisher.
International Organization for Standardization
Case Postale 56 l CH-1211 Gen&e 20 l Switzerland
Printed in Switzerland
ii
0 IS0
IS0 3746: 1995(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 3746 was prepared by Technical Committee
lSO/TC 43, Acoustics, Subcommittee SC 1, Noise.
This second edition cancels and replaces the first edition
(IS0 3746:1979), which has been technically revised.
Annexes A, B and C form an integral part of this International Standard.
Annexes D and E are for information only.

0 IS0
IS0 3746:1995(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 ma-
chines, equipment and their sub-assemblies. When selecting one of the
methods of the IS0 3740 series, it is necessary to select the most ap-
propriate 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 test code for a specific type of machine or equip-
ment, if available, for specifications on mounting and operating conditions.
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 tableO.l), and is used in this International Standard for grade 3
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, it might be possible to use IS0 3747 or 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 basic documents of the IS0 3740 or IS0 9614 series.
If measurements are made in typical machine rooms, where sources are
normally installed, 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 as an A-weighted value directly from the A-
weighted sound pressure level measurements.
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 in time and space.
...