SIST EN ISO 11691:1997
(Main)Acoustics - Measurement of insertion loss of ducted silencers without flow - Laboratory survey method (ISO 11691:1995)
Acoustics - Measurement of insertion loss of ducted silencers without flow - Laboratory survey method (ISO 11691:1995)
This International Standard specifies a laboratory substitution method to determine the insertion loss without flow of ducted, mainly absorbent, circular and rectangular silencers as well as other duct elements for use in ventilating and air-conditioning systems. Note 1: Laboratory measurement procedures for ducted silencers with superimposed flow are described in ISO 7235. This International Standard is applicable to silencers where the design velocity does not exceed 15 m/s. As the method does not include self-generated flow noise, this International Standard is not suitable for tests on silencers where this type of noise is of great importance for the evaluation of the silencer performance. The insertion loss determined according to this International Standard in a laboratory will not necessarily be the same as the insertion loss that will be obtained in an installation in the field. Different sound and flow fields in the duct will yield different results. As this International Standard requires regular test ducts, the results may include some flanking transmission via structural vibrations in the duct walls, that sets an upper limit to the insertion loss that can be determined. Note 2: ISO 7235 gives methods for determining this limit. This International Standard is intended to be used for circular silencers with diameters of 80 mm to 2 000 mm or rectangular silencers with cross-sectional areas within the same range.
Akustik - Messung des Einfügungsdämpfungsmaßes von Schalldämpfern in Kanälen ohne Strömung - Laborverfahren der Genauigkeitsklasse 3 (ISO 11691:1995)
Diese Internationale Norm beschreibt ein Substitutionsverfahren zur Bestimmung des Einfügungsdämpfungsmaßes unter Laborbedingungen von hauptsächlich durch Absorption wirkenden, runden oder rechteckigen Kanalschalldämpfern ohne Strömung sowie von anderen Kanalelementen zum Einsatz in raumlufttechnischen Anlagen. Labormeßverfahren für Kanalschalldämpfer mit überlagerter Strömung werden in der Internationalen Norm ISO 7235 beschrieben.
Acoustique - Détermination de la perte d'insertion de silencieux en conduit sans écoulement - Méthode de mesurage en laboratoire (ISO 11691:1995)
L'IEC 62788-1-4:2016 fournit une méthode de mesure du facteur de transmission optique des matériaux d'encapsulation utilisés dans les modules photovoltaïques (PV). Les mesurages normalisés de cette procédure permettent de quantifier le facteur de transmission prévu de l'encapsulation vers la cellule PV. Le calcul ultérieur du facteur de transmission à pondération solaire permet de comparer les différents matériaux. Les résultats concernant les matériaux non exposés aux intempéries peuvent être utilisés dans les fiches techniques d'un fabricant d'encapsulation, dans le développement des matériaux ou du procédé du fabricant, dans le contrôle de la qualité de fabrication (acceptation du matériau) ou être appliqués dans l'analyse des performances du module. Cette méthode de mesure peut également être utilisée pour contrôler les performances des matériaux d'encapsulation après exposition aux intempéries, afin d'évaluer leur durabilité.
Akustika - Merjenje dodanega dušenja dušilnika zvoka v kanalu brez pretoka - Laboratorijska informativna metoda (ISO 11691:1995)
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN ISO 11691:1997
01-april-1997
Akustika - Merjenje dodanega dušenja dušilnika zvoka v kanalu brez pretoka -
Laboratorijska informativna metoda (ISO 11691:1995)
Acoustics - Measurement of insertion loss of ducted silencers without flow - Laboratory
survey method (ISO 11691:1995)
Akustik - Messung des Einfügungsdämpfungsmaßes von Schalldämpfern in Kanälen
ohne Strömung - Laborverfahren der Genauigkeitsklasse 3 (ISO 11691:1995)
Acoustique - Détermination de la perte d'insertion de silencieux en conduit sans
écoulement - Méthode de mesurage en laboratoire (ISO 11691:1995)
Ta slovenski standard je istoveten z: EN ISO 11691:1995
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
91.140.30 3UH]UDþHYDOQLLQNOLPDWVNL Ventilation and air-
VLVWHPL conditioning
SIST EN ISO 11691:1997 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST EN ISO 11691:1997
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SIST EN ISO 11691:1997
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SIST EN ISO 11691:1997
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SIST EN ISO 11691:1997
IS0
INTERNATIONAL
11691
STANDARD
First edition
1995-08-I 5
Corrected and reprinted
1995-l Z-01
- Measurement of insertion
Acoustics
loss of ducted silencers without flow -
Laboratory survey method
- D&ermina tion de la perte d’insertion de silencieux en
Acous tique
- M&hode de mesurage en laboratoire
conduit sans kcoulement
Reference number
IS0 11691 :I 995(E)
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SIST EN ISO 11691:1997
IS0 11691:1995(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 11691 was prepared by Technical Committee
ISO/TC 43, Acoustics, Subcommittee SC I, Noise.
Annex A of this International Standard is for information only.
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 Geneve 20 l Switzerland
Printed in Switzerland
ii
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SIST EN ISO 11691:1997
Q IS0 IS0 11691:1995(E)
Introduction
The insertion loss of absorbent silencers is generally not affected by the
air flow, provided that the flow velocity does not exceed approximately
20 m/s in the narrowest cross-section of the silencer. In practice, non-
uniform flow distributions must be considered, therefore the limit velocity
of 20 m/s corresponds to a design velocity of 10 m/s to 15 m/s.
. . .
III
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SIST EN ISO 11691:1997
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SIST EN ISO 11691:1997
INTERNATIONAL STANDARD 0 IS0 IS0 11691:1995(E)
Acoustics - Measurement of insertion loss of ducted
silencers without flow - Laboratory survey method
1.2 Measurement uncertainty
1 Scope
Exact information on the precision of the method
cannot be given at this time. Therefore this Inter-
national Standard is denoted a survey standard.
1.1 General
Interlaboratory tests are necessary for the determi-
This International Standard specifies a laboratory sub-
nation of the standard deviation of reproducibility, OR,
stitution method to determine the insertion loss
of the method (relevant terms and methods are given
without flow of ducted, mainly absorbent, circular and
in IS0 5725-l). It is, however, estimated that this
rectangular silencers, as well as other duct elements
method will have a OR which is comparable to that of
for use in ventilating and air-conditioning systems.
IS0 7235. See table 1.
NOTE 1 Laboratory measurement procedures for ducted
silencers with superimposed flow are described in
Table 1 - Estimated values of the standard
IS0 7235.
deviation of reproducibility
This International Standard is applicable to silencers
Midband frequencies of
Standard deviation of
where the design velocity does not exceed 15 m/s.
one-third-octave band
reproducibility, OR
As the method does not include self-generated flow
Hz dB
noise, this International Standard is not suitable for
tests on silencers where this type of noise is of great
50 to 1 250
2
importance for the evaluation of the silencer per-
1600tol0000 3
formance.
The insertion loss determined according to this Inter-
national Standard in a laboratory will not necessarily
2 Normative references
be the same as the insertion loss that will be obtained
in an installation in the field. Different sound and flow
The following standards contain provisions which,
fields in the duct will yield different results. As this
through reference in this text, constitute provisions
International Standard requires regular test ducts, the
of this International Standard. At the time of publi-
results may include some flanking transmission via
cation, the editions indicated were valid. All standards
structural vibrations in the duct walls, that sets an
are subject to revision, and parties to agreements
upper limit to the insertion loss that can be deter-
based on this International Standard are encouraged
mined.
to investigate the possibility of applying the most re-
NOTE 2 IS0 7235 gives methods for determining this cent editions of the standards indicated below.
limit.
Members of IEC and IS0 maintain registers of cur-
rently valid International Standards.
This International Standard is intended to be used for
circular silencers with diameters of 80 mm to IS0 3741 :I 988, Acoustics - Determination of sound
2 000 mm or rectangular silencers with cross- power levels of noise sources - Precision methods
sectional areas within the same range. for broad-band sources in reverberation rooms.
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SIST EN ISO 11691:1997
0 IS0
IS0 11691:1995(E)
3.4 transition element: Element which fits and
IS0 3743-l :I 994, Acoustics - Determination of
sound power levels of noise sources - Engineering connects the duct of the sound source to the test
methods for small, movable sources in reverberant duct and, in some cases, the test duct to the silencer.
- Part 1: Comparison method for hard-walled
fields
3.5 standard duct: Sheet metal duct commercially
test rooms.
available directly from stock and normally used in
IS0 3744:1994, Acoustics - Determination of sound
practical applications together with the silencer under
power levels of noise sources using sound pressure
test.
- Engineering method in an essentially free field over
NOTE 3 Normal wall thicknesses for standard ducts lie in
a reflecting plane.
the range 0,4 mm for small circular ducts to I,25 mm for
large circular ducts. A common thickness for rectangular
IS0 7235:1991, Acoustics - Measurement pro-
ducts is 0,9 mm.
cedures for ducted silencers - Insertion loss, flow
noise and total pressure loss.
IS0 9614-1 :I 993, Acoustics - Determination of 4 Test facility
sound power levels of noise sources using sound in-
tensity - Part 1: Measurement at discrete points.
4.1 General
IEC 651 :I 979, Sound level meters, and Amendment
The test facility shall consist of the equipment shown
1:1993.
in figure 1. It contains the following:
I EC 804: 1985, Integrating-averaging sound level me-
- the sound measuring equipment (see 4.2);
ters, Amendment 1 :I 989 and Amendment 2:1993.
- the sound source equipment (see 4.3);
I EC 942: 1988, Sound calibrators.
- the transition element(s) (see 4.4);
I EC 1260:~‘1, Electroacoustics - Octave-band and
fractional-octave-band filters.
- the test ducts (see 4.5);
- the substitution duct (see 4.5);
3 Definitions
- the measurement environment appropriate to the
For the purposes of this International Standard, the
standard used to determine the sound power
following definitions apply.
level.
3.1 insertion loss, D: Reduction in level of sound
NOTE 4 If IS0 3741 is used to determine the sound
power propagating through a duct due to the insertion
power level, a reverberation room is used (see 4.6). This is
of a silencer into the duct system in place of a sub-
the preferred method.
stitution duct. It is expressed in decibels.
3.2 test duct: Straight standard duct of constant
4.2 Sound measuring equipment
cross-section in front of and behind the silencer under
test. The purpose of the test ducts is to separate the
The instrumentation system, including the micro-
test object from the sound source and the
phone and cable, shall meet the requirements for a
reverberation room.
type 1 instrument specified
...
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