SIST EN ISO 11546-2:2009

Acoustics - Determination of sound insulation performances of enclosures - Part 2: Measurements in situ (for acceptance and verification purposes) (ISO 11546-2:1995)

Specifies in situ methods for the determination of the sound insulation performance of machine enclosures. Does apply to a total enclosure only.

Akustik - Bestimmung der Schalldämmung von Schallschutzkapseln - Teil 2: Messungen im Einsatzfall (zum Zweck der Abnahme und Nachprüfung) (ISO 11546-2:1995)

Acoustique - Détermination de l'isolement acoustique des encoffrements - Partie 2: Mesurages sur site (aux fins d'acceptation et de vérification) (ISO 11546-2:1995)

La présente partie de l'ISO 11546 prescrit des méthodes de détermination in situ de l'isolement acoustique (perte d'insertion) d'encoffrements de machines. Elle s'applique uniquement à un encoffrement complet et non pas aux panneaux individuels qui le composent.  
NOTES 1 L'isolement acoustique des panneaux constitutifs d'encoffrements tels que: éléments de paroi, portes, fenêtres, silencieux, etc. devrait être mesuré suivant les normes appropriées. 2 Il existe des normes relatives à la détermination de l'isolement acoustique des encoffrements dans des conditions de laboratoire (ISO 11546-1), et des cabines (ISO 11957). Les méthodes de mesurage prescrites dans la présente partie de l'ISO 11546 sont basées sur les Normes internationales des séries ISO 3740, ISO 9614 et ISO 11200 (voir tableau 1). Suivant la méthode choisie, l'isolement acoustique de l'encoffrement (perte d'insertion) est exprimé en termes de réduction du niveau de puissance acoustique ou du niveau de pression acoustique. Les méthodes sont données pour des mesurages effectués lorsque l'encoffrement entoure la source sonore réelle (machine). Lorsque ces méthodes ne sont pas applicables, d'autres mesurages peuvent être effectués avec une source de bruit artificielle. De telles méthodes sont aussi décrites dans la présente partie de l'ISO 11546.

Akustika - Ugotavljanje zvočno izolacijskih lastnosti okrovov - 2. del: Terenska merjenja (za prevzem in preverjanje) (ISO 11546-2:1995)

General Information

• Status: Published
• Public Enquiry End Date: 19-Jun-2009
• Publication Date: 12-Oct-2009
• ICS: 17.140.01 - Acoustic measurements and noise abatement in general
• Technical Committee: AKU - Acoustics
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 28-Aug-2009
• Due Date: 02-Nov-2009
• Completion Date: 13-Oct-2009
• Directive: 2006/42/EC - 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)
• Directive: 89/392/EEC - Machinery - Safety of machinery: general essential health and safety requirements
• Directive: 98/37/EC - Machinery
• Mandate: M/BC/CEN/88/13 - Standardization request to CEN/CENELEC relating to machinery
• Ref Project: EN ISO 11546-2:2009 - Acoustics - Determination of sound insulation performances of enclosures - Part 2: Measurements in situ (for acceptance and verification purposes) (ISO 11546-2:1995)

Relations

• Replaces: SIST EN ISO 11546-2:1997 - Acoustics - Determination of sound insulation performances of enclosures - Part 2: Measurements in situ (for acceptance and verification purposes) (ISO 11546-2:1995)
• Effective Date: 01-Nov-2009

Overview

EN ISO 11546-2:2009 (ISO 11546-2:1995) is a CEN/ISO acoustics standard that specifies in situ methods for determining the sound insulation performance (insertion loss) of machine enclosures. It applies to a complete enclosure only (not to individual panels such as doors or windows) and is intended for acceptance and verification measurements on installed equipment. The standard supports conformity assessment under relevant EU machinery Directives when applied within its scope.

Key topics and requirements

• Scope and applicability
  • Measurement methods are for a total enclosure surrounding the actual noise source (machine). Alternative methods using an artificial sound source are given when the actual source cannot be used.
• Measurement objectives
  • Quantify the enclosure performance in terms of sound power reduction or sound pressure level reduction (insertion loss).
• Measurement methods
  • Procedures for measurements when the enclosure surrounds the actual sound source and for the artificial sound source method where necessary.
• Instrumentation and test conditions
  • Requirements for instruments, test positions and environmental conditions are provided and reference related ISO measurement practice standards.
• Data handling
  • Guidance on uncertainty estimation, information to be recorded during tests, and information to be reported in test reports.
• Annexes (informative)
  • Annex A: design of an artificial sound source
  • Annex B: example source spectrum
  • Annex C: evaluating suitability of test environments for in situ work
  • Annex D: estimating noise insulation for a given noise spectrum
  • Annex E: bibliography and references

Applications and who uses it

EN ISO 11546-2 is intended for practical use by:

• Acoustic consultants and measurement laboratories performing on-site verification and acceptance tests
• OEMs and machine manufacturers validating enclosure performance on installed machinery
• Compliance and safety engineers demonstrating conformity with noise-related requirements under EU machinery directives
• Facility managers and maintenance teams assessing the effectiveness of sound enclosures in real operating conditions

Typical applications include field testing of acoustic enclosures, verifying claimed insertion loss during commissioning, and troubleshooting inadequate noise control.

Related standards

Key related ISO standards referenced for methods and instrumentation:

• ISO 11546-1 (laboratory measurements / declaration)
• ISO 3743, ISO 3746, ISO 3747 (sound power determination methods)
• ISO 9614 (sound intensity methods)
• ISO 11200, ISO 11201, ISO 11202 (noise emission and measurement at workstations)
• ISO 717-1 (rating of airborne sound insulation)
• ISO 4871 (noise declaration and verification for machinery)

By following EN ISO 11546-2, practitioners can perform consistent, documented in situ sound insulation tests of machine enclosures and produce reliable results for acceptance, verification and regulatory compliance.

Standards Content (Sample)

SLOVENSKI STANDARD
01-november-2009
1DGRPHãþD
SIST EN ISO 11546-2:1997
$NXVWLND8JRWDYOMDQMH]YRþQRL]RODFLMVNLKODVWQRVWLRNURYRYGHO7HUHQVND
PHUMHQMD]DSUHY]HPLQSUHYHUMDQMH,62
Acoustics - Determination of sound insulation performances of enclosures - Part 2:
Measurements in situ (for acceptance and verification purposes) (ISO 11546-2:1995)
Akustik - Bestimmung der Schalldämmung von Schallschutzkapseln - Teil 2: Messungen
im Einsatzfall (zum Zweck der Abnahme und Nachprüfung) (ISO 11546-2:1995)
Acoustique - Détermination de l'isolement acoustique des encoffrements - Partie 2:
Mesurages sur site (aux fins d'acceptation et de vérification) (ISO 11546-2:1995)
Ta slovenski standard je istoveten z: EN ISO 11546-2:2009
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 11546-2
NORME EUROPÉENNE
EUROPÄISCHE NORM
August 2009
ICS 17.140.01 Supersedes EN ISO 11546-2:1995
English Version
Acoustics - Determination of sound insulation performances of
enclosures - Part 2: Measurements in situ (for acceptance and
verification purposes) (ISO 11546-2:1995)
Acoustique - Détermination de l'isolement acoustique des Akustik - Bestimmung der Schalldämmung von
encoffrements - Partie 2: Mesurages sur site (aux fins Schallschutzkapseln - Teil 2: Messungen im Einsatzfall
d'acceptation et de vérification) (ISO 11546-2:1995) (zum Zweck der Abnahme und Nachprüfung) (ISO 11546-
2:1995)
This European Standard was approved by CEN on 3 August 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 11546-2:2009: 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 11546-2:1995 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 11546-2:2009 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 11546-2:1995.
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 11546-2:1995 has been approved by CEN as a EN ISO 11546-2:2009 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.
ISO
INTERNATIONAL
STANDARD 11546-2
First edition
1995-12-15
- Determination of Sound
Acoustics
insulation performances of enclosures -
Part 2:
Measurements in sifu (for acceptance and
verification purposes)
Acoustique - Dhermination de I’isolemen t acoustique des
encoffremen ts -
Partie 2: Mesurages sur sjte (aux fins d’accepta Gon et de v&ification)
Reference number
ISO 11546-2:1995(E)
ISO 11546-2:1995(E)
Contents
Page
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1 Scope
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2 Normative references . . . .
3 Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*.*.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .s.
4 Choice of measurement method
Instrumentation . .
6 Test methods applicable to enclosures with the actual Sound
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .~. 4
Source
6.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.2 Determination of Sound power insulation
6.3 Determination of Sound pressure insulation at a specified
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .~. . . . . . . . . . . . . . . . . . . . . . . . 5
Position
7 Test methods applicable to enclosures without the actual Sound
Source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
7.2 Artificial Sound Source method
7.3 Weighted Sound power insulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7.4 Estimated noise insulation due to the enclosure for a specific
noise spectrum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .~.
8 Uncertainty . .
Information to be recorded . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .a. 7
................................... 7
9.1 Test Object .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9.2 Test conditions
9.3 I nstrumentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9.4 Acoustical data
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
9.5 Further information
IO Information to be reported . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
0 ISO 1995
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced
or utilized in any form or by any means, electronie or mechanical, including photocopying and
microfilm, without Permission in writing from the publisher.
International Organization for Standardization
Case Postale 56 l CH-1 211 Geneve 20 l Switzerland
Printed in Switzerland
ii
0 ISO
ISO 11546=2:1995(E)
Annexes
A Artificial Sound Source . . . . . . . . . . .*.
B Example of a Source spectrum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
C Guidelines for evaluating the applicability of different test
environments for in situ measurements
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
D Estimated noise insulation due to the enclosure for a specific
noise spectrum
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
E Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
. . .
Ill
0 ISO
ISO 11546=2:1995(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. Esch 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.
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 ISO 115462 was prepared by Technical Committee
lSO/TC 43, Acoustics, Subcommittee SC 1, Noise.
ISO 11546 consists of the following Parts, under the general title Acous-
tks - Determination of Sound insulation performances of enclosures:
- Part 7: Measuremen ts under laboratory conditions (for declaration
purposes)
- Part 2: Measurements in situ (for acceptance and verification pur-
poses)
Annex A forms an integral part of this part of ISO 11546. Annexes B, C,
D and E are for information only.

ISO 11546=2:1995(E)
INTERNATIONAL STANDARD 0 ISO
- Determination of sound insulation
Acoustics
performances of enclosures -
Part 2:
Measurements in sifu (for acceptance and verification
purposes)
1 Scope 2 Normative references
The following Standards contain provisions which,
through reference in this text, constitute provisions
This part of ISO 11546 specifies in situ methods for
the determination of the Sound insulation perform- of this part of ISO 11546. At the time of publication,
ante (insertion loss) of machine enclosures. the editions indicated were valid. All Standards are
subject to revision, and Parties to agreements based
lt applies to a total enclosure only and not to the in- on this part of ISO 11546 are encouraged to investi-
dividual Panels from which the enclosure is made. gate the possibility of applying the most recent edi-
tions of the Standards indicated below. Members of
NOTES
IEC and ISO maintain registers of currently valid
International Standards.
1 Sound insulation for enclosure Panels such as wall el-
ements, doors, windows, silencers, etc. should be
ISO 140-6: 1978, Acoustics - Measurement of Sound
measured in accordance with other relevant Standards.
insulation in buildings and of building elemen ts -
2 Related Standards concern noise-attenuation measure- Part 6: Laboratory measurements of Impact Sound
enclosures under laboratoty conditions
ments of
insulation of floors.
(ISO 11546-1) and cabins (ISO 11957).
ISO 717-1: -l), Acoustics - Rating of Sound insu-
The measurement methods specified in this part of
lation in buildings and of building elements - Part 1:
ISO 11546 are based on International Standards in the
Airborne Sound insulation.
series ISO 3740, ISO 9614 and ISO 11200 (see
table 1). Depending on the method Chosen, the Sound
ISO 3743-1 :1994, Acoustics - Determination of
insulation Performance (insertion loss) of the enclos-
Sound power levels of noise sources - Engineering
ure is determined in terms of the reduction of Sound methods for small, movable sources in reverberant
power level or Sound pressure level. Methods are fields - Part 1: Comparison method for hard-walled
given for measurements where the enclosure sur- tes t rooms.
rounds the actual Sound Source (machine). When
these methods are not practicable, alternative ISO 374411994, Acoustics - Determination of Sound
power levels of noise sources using Sound pressure
measurements tan be performed with an artificial
- Engineering method in an essentially free field over
Sound Source. Such methods are also described in
a reflecting plane.
this part of ISO 11546.
1) To be published. (Revision of ISO 717-1:1982 and ISO 717-3:1982)

0 ISO
ISO 11546=2:1995(E)
ISO 3746:1995, Acoustics - Determination of Sound 3.1 A-weighting: Frequency weighting as defined
power levels of noise sources using Sound pressure in IEC 651.
- Survey method using an enveloping measurement
surface over a reflecting plane. 3.2 enclosure: A structure enveloping a noise
Source (machine), designed to protect the environ-
ISO 3747:1987, Acoustics - Determination of Sound ment from this noise Source (machine).
power levels of noise sources - Survey method us-
NOTE 3 An enclosure tan be, for example, a freestanding
ing a reference Sound Source.
structure terminated on the floor or a structure more or less
fixed to the machine. (Concerning enclosures fixed to the
ISO 4871:- *‘, Acoustics - Declara tjon and ven’fica-
machine, see clause 4.)
tion of noise emission values of machinery and
equipmen t.
3.3 Sound pressure level, L,,: Ten times the logar-
ithm to the base 10 of the ratio of the Square of the
ISO 9614-1 :1993, Acoustics - Determination of
Sound pressure of a Sound to the Square of the ref-
Sound power levels of noise sources using Sound in-
erence Sound pressure. Sound pressure levels are
Part 1: Measuremen t at discrete Points.
tensity -
expressed in decibels. The reference Sound pressure
is 20 PPa (2 x 10V5 Pa).
ISO 9614-2:-3), Acoustics - Determination of Sound
power levels of noise sources using Sound intensity
3.4 average Sound pressure level, 4: Mean-Square
- Part 2: Measurement by scanning.
of the Sound pressure levels:
ISO 11201: 1995, Acoustics - Noise emitted by ma-
OJL,l + 1 OOJL,, + . + 1 OWLi,’ dB
chinery and equipment - Measurement of emission
L,=lOlg Io
n
i 1
Sound pressure levels at a work Station and at other
specified positions - Engineering method in an es-
where Lp,, Lp2, . . . . Lpn are the Sound pressure levels,
sentially free field over a reflecting plane.
in decibels, to be averaged.
ISO 11202:1995, Acoustics - Noise emitted by ma-
3.5 Sound power level, L,: Ten times the logarithm
chinery and equipment - Measurement of emission
to the base 10 of the ratio of a given Sound power to
Sound pressure levels at a work Station and at other
the reference Sound power. lt is expressed in deci-
specified positions - Survey method in sjtu.
bels. The reference Sound power is 1 pW (1 O- l2 W).
ISO 11204: 1995, Acoustics - Noise emitted by ma-
3.6 average Sound power level, &: Mean-Square
chinery and equipment - Measurement of emission
of the Sound power levels:
Sound pressure levels at a work Station and at other
specified positions - Method requiring environ-
L,= 10 Ig i 1p-w’ + 1 oQKv2 + . + 1 OOL 1 dB
mental corrections.
n
I EC 651: 1979, Sound level meters.
are the Sound power levels, in
where kl, LU/21 .I Lw,
decibels, to be averaged.
I EC 804: 1985, In tegra ting-averaging Sound level
me ters.
3.7 Sound power insulation, D,: Reduction in
Sound power level obtained due to the enclosure
I EC 942: 1988, Sound calibrators.
(octave bands or one-third-octave bands). lt is ex-
pressed in decibels.
I EC 1 260:-4), Electroacoustics - Octave-band and
fractional-octave-band filters.
3.8 A-weighted Sound power insulation, DwA:
Reduction in the A-weighted Sound power level ob-
tained due to the enclosure for the actual Sound
Source spectrum. lt is expressed in decibels.
3 Definitions
For the purposes of this part of ISO 11546, the fol- 3.9 Sound pressure insulation, D,,: Reduction in the
lowing definitions apply. Sound pressure level at a specified Position due to the
2) To be published. (Revision of ISO 4871:1984)
3) To be published.‘
4) To be published. (Revision of IEC 225:1966)

Q ISO
ISO 11546=2:1995(E)
In some .specific cases, an artificial Sound Source tan
enclosure (octave bands or one-third-octave bands). It
be used instead of the Sound Source, for which the
is expressed in decibels.
enclosure is intended. This method may, for example,
3.10 A-weighted Sound pressure insulation, DPA:
be used in cases where the actual Sound Source
Reduction in A-weighted Sound pressure level at a
(machine) cannot work without auxiliary equipment
specified Position due to the enclosure for the actual
with a high noise level. Furthermore, an artificial
Sound Source spectrum. lt is expressed in decibels. Sound Source may be used in cases where it is im-
possible to achieve identical operating conditions for
3.11 estimated noise insulation due to the en-
the machine during measurements with and without
closure, DwA, or DpAe: Calculated reduction in A-
an enclosure, respectively.
weighted Sound power or Sound pressure level
obtained from D, or DP, measured in accordance with
The leak ratio of an enclosure measured in accordance
this part of ISO 11546, and a specific noise spectrum.
with this part of ISO 11546 with an artificial Sound
(See annex C.) lt is expressed in decibels.
Source should be small (0 preferably less than 2 %)
and the interior surfaces of the enclosure should be
3.12 weighted Sound power insulation, Dww:
Sound absorbing.
Single-number value determined in accordance with
the method stated in ISO 717-1 except that the Sound NOTE 7 The more the enclosure deviates from these
ideal conditions regarding leak ratio and absorption, the
reduction index is replaced by the Sound power insu-
more there is a need to take measurements using the actual
lation, D,. lt is expressed in decibels.
Sound Source.
3.13 fill ratio, 4: Ratio of the volume of the Source
In cases where a Single-number value is wanted
in an enclosure to the interior volume of that enclos-
based on measurements carried out with the artificial
ure.
Sound Source method, the weighted Sound power in-
In cases where the shape of the Source complicates
sulation, D,,, is the preferred quantity (see definition
calculation of the Source volume, the volume of a
3.12). The ‘weighted Sound power insulation is a
reference box determined in accordance with
practicable Single-number value to be used for a rough
ISO 3744 or ISO 3746 tan be used.
comparison of different enclosures. However, this
quantity must not be taken as a general measure of
3.14 leak ratio, 8: Ratio between the area of all
the Sound insulation Performance of the enclosure,
openings of the enclosure and the total interior sur-
as the Performance in actual situations strongly de-
face area of the enclosure (including openings).
pends on the spectrum of the actual noise.
NOTES
This part of ISO 11546 is intended for use together
with a relevant International Standard for the deter-
4 Openings provided with sufficiently efficient sound-
mination of Sound power level or measurement of
attenuating silencers are not regarded as openings with re-
Sound pressure level. The applicability of the different
spect to the leak ratio.
methods described is summarized in table 1 and in
5 The reciprocal value of the leak ratio is designated the
annex C.
seal ratio, Y (Y = l/@.
The requirement concerning the maximum volume of
4 Choice of measurement method the enclosure, as given by the relevant International
Standard selected from table 1, shall be fulfilled.
Accurate values of the Sound insulation Performance
of an enclosure tan only be obtained when the
If the actual noise spectrum is known or tan be as-
measurements take place with the actual Sound
sumed, the reduction in A-weighted noise level due
Source for which the enclosure is designed. Thus,
to the enclosure tan be estimated according to the
whenever practicable, methods using the real Source
method given in annex D.
shall be used. If the enclosure is fixed or otherwise
connected to the Sound Source, the Sound insulation NOTE 8 Measurement data obtained using the actual
Sound Source are not necessarily comparable with data ob-
Performance tan only be determined with the actual
tained using an artificial Sound Source. In cases where the
Sound Source.
actual Sound Source is connected to the enclosure,
structure-borne Sound may influence the measurement re-
NOTE 6 The result of an in sjtu measurement depends
sult.
on the enclosure construction and the workmanship when
installed.
0 ISO
ISO 11546=2:1995(E)
Table 1 - Applicability of the different test methods
International Symboll) Sub-
Test environment
Test method
Standard clause
Hard-walled test room ISO 3743-1
DW, DWA
Outdoors or in large room ISO 3744
DW, DWA
ISO 3746 D 6.1
No special test environment
WA
6.2
No special test environment ISO 3747
DWl DWA
ISO 9614-1
Actual Sound Source
No special test environment
DWl DWA
ISO 9614-2
Free-field over a reflecting plane; indoor or
ISO 11201
Dp~ DpA
outdoor
6.1
No special test environment ISO 11
...