SIST EN ISO 11691:2021
(Main)Acoustics - Measurement of insertion loss of ducted silencers without flow - Laboratory survey method (ISO 11691:2020)
Acoustics - Measurement of insertion loss of ducted silencers without flow - Laboratory survey method (ISO 11691:2020)
This document 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 Laboratory measurement procedures for ducted silencers with superimposed flow are described in
ISO 7235[5].
This document 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 document is not suitable for tests on silencers
where this type of noise is of great importance for the evaluation of the silencer performance. As most
silencers, particularly in offices and dwelling, have design velocities below 15 m/s, this document can
often be a cost-efficient alternative to ISO 7235[5].
The insertion loss determined according to this document in a laboratory is not necessarily the same
as the insertion loss obtained in an installation in the field. Different sound and flow fields in the duct
yield different results. In this document, the sound field is dominated by plane wave modes. Due to the
use of regular test ducts, the results can include some flanking transmission via structural vibrations
in the duct walls that sets an upper limit to the insertion loss that can be determined.
This document is intended to be used for circular silencers with diameters of 80 mm to 2 000 mm or for
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 11691:2020)
Dieses Dokument legt ein Substitutionsverfahren zur Bestimmung des Einfügungsdämpfungsmaßes unter Laborbedingungen von runden oder rechteckigen, hauptsächlich absorbierend wirkenden Kanalschall-dämpfern ohne Strömung sowie von anderen Kanalelementen zum Einsatz in raumlufttechnischen Anlagen fest.
ANMERKUNG Labormessverfahren für Kanalschalldämpfer mit überlagerter Strömung werden in ISO 7235 [5] beschrieben.
Dieses Dokument gilt für Schalldämpfer mit einer Auslegungsgeschwindigkeit von höchstens 15 m/s. Da in diesem Dokument das Strömungsgeräusch nicht behandelt wird, eignet es sich nicht zur Anwendung auf solche Schalldämpfer, bei denen diese Art des Geräusches wesentlich für die Beurteilung der Wirkung des Schalldämpfers ist. Da die meisten Schalldämpfer, insbesondere in Büro- und Wohnräumen, niedrigere Auslegungsgeschwindigkeiten als 15 m/s aufweisen, kann dieses Dokument häufig eine wirtschaftliche Alternative zu ISO 7235 [5] darstellen.
Das nach diesem Dokument in einem Labor ermittelte Einfügungsdämpfungsmaß ist nicht notwendigerweise gleich dem Einfügungsdämpfungsmaß, das sich in einer Anlage unter Betriebsbedingungen ergibt. Unterschiedliche Schall- und Strömungsfelder im Kanal führen zu unterschiedlichen Ergebnissen. In diesem Dokument überwiegen beim Schallfeld ebene Wellenformen. Durch den Einsatz von üblichen Prüfkanälen können die Messergebnisse Beiträge durch Nebenwegübertragung von Körperschall über die Kanalwände enthalten, wodurch das bestimmbare Einfügungsdämpfungsmaß nach oben beschränkt wird.
Dieses Dokument ist vorgesehen zur Anwendung auf runde Schalldämpfer mit Durchmessern von 80 mm bis 2 000 mm und für rechteckige Schalldämpfer mit Querschnittsflächen derselben Größenordnung.
Acoustique - Détermination de la perte d'insertion de silencieux en conduit sans écoulement - Méthode de mesurage en laboratoire (ISO 11691:2020)
Specifies a laboratory substitution method to determine the insertion loss of ducted circular and rectangular silencers without flow, as well as other duct elements for use in ventilating and air-conditioning systems.
Akustika - Merjenje dodanega dušenja dušilnika zvoka v kanalu brez pretoka - Laboratorijska informativna metoda (ISO 11691:2020)
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN ISO 11691:2021
01-marec-2021
Nadomešča:
SIST EN ISO 11691:2009
Akustika - Merjenje dodanega dušenja dušilnika zvoka v kanalu brez pretoka -
Laboratorijska informativna metoda (ISO 11691:2020)
Acoustics - Measurement of insertion loss of ducted silencers without flow - Laboratory
survey method (ISO 11691:2020)
Akustik - Messung des Einfügungsdämpfungsmaßes von Schalldämpfern in Kanälen
ohne Strömung - Laborverfahren der Genauigkeitsklasse 3 (ISO 11691:2020)
Acoustique - Détermination de la perte d'insertion de silencieux en conduit sans
écoulement - Méthode de mesurage en laboratoire (ISO 11691:2020)
Ta slovenski standard je istoveten z: EN ISO 11691:2020
ICS:
17.140.01 Akustična merjenja in Acoustic measurements and
blaženje hrupa na splošno noise abatement in general
91.120.20 Akustika v stavbah. Zvočna Acoustics in building. Sound
izolacija insulation
SIST EN ISO 11691:2021 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
---------------------- Page: 1 ----------------------
SIST EN ISO 11691:2021
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SIST EN ISO 11691:2021
EN ISO 11691
EUROPEAN STANDARD
NORME EUROPÉENNE
November 2020
EUROPÄISCHE NORM
ICS 91.120.20 Supersedes EN ISO 11691:2009
English Version
Acoustics - Measurement of insertion loss of ducted
silencers without flow - Laboratory survey method (ISO
11691:2020)
Acoustique - Détermination de la perte d'insertion de Akustik - Messung des Einfügungsdämpfungsmaßes
silencieux en conduit sans écoulement - Méthode de von Schalldämpfern in Kanälen ohne Strömung -
contôle en laboratoire (ISO 11691:2020) Laborverfahren der Genauigkeitsklasse 3 (ISO
11691:2020)
This European Standard was approved by CEN on 22 July 2020.
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-CENELEC 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-CENELEC 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, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2020 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 11691:2020 E
worldwide for CEN national Members.
---------------------- Page: 3 ----------------------
SIST EN ISO 11691:2021
EN ISO 11691:2020 (E)
Contents Page
European foreword . 3
2
---------------------- Page: 4 ----------------------
SIST EN ISO 11691:2021
EN ISO 11691:2020 (E)
European foreword
This document (EN ISO 11691:2020) has been prepared by Technical Committee ISO/TC 43 "Acoustics"
in collaboration with Technical Committee CEN/TC 211 “Acoustics” the secretariat of which is held by
DIN.
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 May 2021, and conflicting national standards shall be
withdrawn at the latest by May 2021.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 11691:2009.
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, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the
United Kingdom.
Endorsement notice
The text of ISO 11691:2020 has been approved by CEN as EN ISO 11691:2020 without any modification.
3
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SIST EN ISO 11691:2021
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SIST EN ISO 11691:2021
INTERNATIONAL ISO
STANDARD 11691
Second edition
2020-07
Acoustics — Measurement of insertion
loss of ducted silencers without flow
— Laboratory survey method
Acoustique — Détermination de la perte d'insertion de silencieux en
conduit sans écoulement — Méthode de contôle en laboratoire
Reference number
ISO 11691:2020(E)
©
ISO 2020
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SIST EN ISO 11691:2021
ISO 11691:2020(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2020
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved
---------------------- Page: 8 ----------------------
SIST EN ISO 11691:2021
ISO 11691:2020(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Test facility and arrangement . 2
4.1 General . 2
4.2 Sound measuring equipment . 3
4.3 Sound source equipment . 4
4.3.1 General. 4
4.3.2 Electronic equipment, loudspeaker unit and transition element . 4
4.3.3 Modal filter . 4
4.4 Transition element . 5
4.5 Test ducts and substitution duct. 5
4.6 Reverberation room . 5
4.7 Other measurement environments . 5
5 Test procedure . 5
6 Measurement uncertainty . 6
7 Information to be recorded . 6
7.1 General . 6
7.2 Description of the silencer under test. 6
7.3 Description of the test arrangement . 7
7.4 Acoustical test result . 7
8 Information to be reported . 7
Bibliography . 8
© ISO 2020 – All rights reserved iii
---------------------- Page: 9 ----------------------
SIST EN ISO 11691:2021
ISO 11691:2020(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.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
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. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www .iso .org/
iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 43, Acoustics, Subcommittee SC 1, Noise.
This second edition cancels and replaces the first edition (ISO 11691:1995), which has been technically
revised. The main changes compared to the previous edition are as follows:
— a modal filter has been inserted after the source to bring the standard more in line with the
[5]
corresponding arrangements in ISO 7235:2003 , and
— in this edition, test ducts and test object should, if possible, have the same cross-sections.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
iv © ISO 2020 – All rights reserved
---------------------- Page: 10 ----------------------
SIST EN ISO 11691:2021
ISO 11691:2020(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.
© ISO 2020 – All rights reserved v
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SIST EN ISO 11691:2021
---------------------- Page: 12 ----------------------
SIST EN ISO 11691:2021
INTERNATIONAL STANDARD ISO 11691:2020(E)
Acoustics — Measurement of insertion loss of ducted
silencers without flow — Laboratory survey method
1 Scope
This document 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 Laboratory measurement procedures for ducted silencers with superimposed flow are described in
[5]
ISO 7235 .
This document 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 document is not suitable for tests on silencers
where this type of noise is of great importance for the evaluation of the silencer performance. As most
silencers, particularly in offices and dwelling, have design velocities below 15 m/s, this document can
[5]
often be a cost-efficient alternative to ISO 7235 .
The insertion loss determined according to this document in a laboratory is not necessarily the same
as the insertion loss obtained in an installation in the field. Different sound and flow fields in the duct
yield different results. In this document, the sound field is dominated by plane wave modes. Due to the
use of regular test ducts, the results can include some flanking transmission via structural vibrations
in the duct walls that sets an upper limit to the insertion loss that can be determined.
This document is intended to be used for circular silencers with diameters of 80 mm to 2 000 mm or for
rectangular silencers with cross-sectional areas within the same range.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 3741, Acoustics — Determination of sound power
...
SLOVENSKI STANDARD
oSIST prEN ISO 11691:2019
01-julij-2019
Akustika - Merjenje dodanega dušenja dušilnika zvoka v kanalu brez pretoka -
Laboratorijska informativna metoda (ISO/DIS 11691:2019)
Acoustics - Measurement of insertion loss of ducted silencers without flow - Laboratory
survey method (ISO/DIS 11691:2019)
Akustik - Messung des Einfügungsdämpfungsmaßes von Schalldämpfern in Kanälen
ohne Strömung - Laborverfahren der Genauigkeitsklasse 3 (ISO/DIS 11691:2019)
Acoustique - Détermination de la perte d'insertion de silencieux en conduit sans
écoulement - Méthode de mesurage en laboratoire (ISO/DIS 11691:2019)
Ta slovenski standard je istoveten z: prEN ISO 11691
ICS:
17.140.01 Akustična merjenja in Acoustic measurements and
blaženje hrupa na splošno noise abatement in general
91.120.20 Akustika v stavbah. Zvočna Acoustics in building. Sound
izolacija insulation
oSIST prEN ISO 11691:2019 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
---------------------- Page: 1 ----------------------
oSIST prEN ISO 11691:2019
---------------------- Page: 2 ----------------------
oSIST prEN ISO 11691:2019
DRAFT INTERNATIONAL STANDARD
ISO/DIS 11691
ISO/TC 43/SC 1 Secretariat: DIN
Voting begins on: Voting terminates on:
2019-04-10 2019-07-03
Acoustics — Measurement of insertion loss of ducted
silencers without flow — Laboratory survey method
Acoustique — Détermination de la perte d'insertion de silencieux en conduit sans écoulement — Méthode
de mesurage en laboratoire
ICS: 91.120.20
THIS DOCUMENT IS A DRAFT CIRCULATED
This document is circulated as received from the committee secretariat.
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
ISO/CEN PARALLEL PROCESSING
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/DIS 11691:2019(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
©
PROVIDE SUPPORTING DOCUMENTATION. ISO 2019
---------------------- Page: 3 ----------------------
oSIST prEN ISO 11691:2019
ISO/DIS 11691:2019(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2019
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2019 – All rights reserved
---------------------- Page: 4 ----------------------
oSIST prEN ISO 11691:2019
ISO/DIS 11691:2019(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
1.1 General . 1
1.2 Measurement uncertainty . 1
2 Normative references . 2
3 Terms and definitions . 2
4 Test facility . 3
4.1 General . 3
4.2 Sound measuring equipment . 4
4.3 Sound source equipment . 5
4.3.1 General. 5
4.3.2 Electronic equipment, loudspeaker unit and transition element . 5
4.3.3 Modal filter . 5
4.4 Transition elements . 6
4.5 Test and substitution ducts . 6
4.6 Reverberation room . 6
4.7 Other measurement environments . 6
5 Test procedure . 6
6 Information to be recorded . 7
6.1 General . 7
6.2 Description of the silencer under test. 7
6.3 Description of test arrangement . 7
6.4 Acoustical test result . 8
7 Information to be reported . 8
Annex ZA (informative) Relationship between this European Standard and the essential
requirements of Directive 2006/42/EC aimed to be covered . 9
Bibliography .10
© ISO 2019 – All rights reserved iii
---------------------- Page: 5 ----------------------
oSIST prEN ISO 11691:2019
ISO/DIS 11691:2019(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.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/directives).
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. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following
URL: www .iso .org/iso/foreword .html.
This document was prepared by ISO/TC 43, Acoustics, Subcommittee SC 1, Noise.
This second edition cancels and replaces the first edition (ISO 11691:1995), which has been technically
revised.
iv © ISO 2019 – All rights reserved
---------------------- Page: 6 ----------------------
oSIST prEN ISO 11691:2019
ISO/DIS 11691:2019(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.
© ISO 2019 – All rights reserved v
---------------------- Page: 7 ----------------------
oSIST prEN ISO 11691:2019
---------------------- Page: 8 ----------------------
oSIST prEN ISO 11691:2019
DRAFT INTERNATIONAL STANDARD ISO/DIS 11691:2019(E)
Acoustics — Measurement of insertion loss of ducted
silencers without flow — Laboratory survey method
1 Scope
1.1 General
This document 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 document 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 document is not suitable for tests on silencers
where this type of noise is of great importance for the evaluation of the silencer performance. As most
silencers, particularly in offices and dwelling, have design velocities below 15 m/s this document can
often be a cost efficient alternative to ISO 7235.
The insertion loss determined according to this document 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. In this document the sound field will be dominated by
plane wave modes. As this document 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 document is intended to be used for circular silencers with diameters of 80 mm to 2000 mm or
rectangular silencers with cross-sectional areas within the same range.
1.2 Measurement uncertainty
Due to lack of knowledge the determination of the uncertainty of results obtained from measurements
[2]
according to this document does not comply with ISO/IEC Guide 98-3 . Exact information on the
precision of the method cannot be given at this time. Therefore this document is denoted a survey
standard. However, due to a simpler and more narrowly defined test set-up it is estimated that this
method will have a standard deviation of reproducibility, σ , as defined in ISO 5725-2, which is equal to
R
or better than that of ISO 7235. See Table 1.
Table 1 — Estimated values of the standard deviation of reproducibility
Mid-band frequencies of the one- Standard deviation of reproducibili-
third-octave band ty, σ , of the insertion loss
Ri
Hz dB
50 to 100 1,5
125 to 500 1
630 to 1 250 2
1 600 to 10 000 3
© ISO 2019 – All rights reserved 1
---------------------- Page: 9 ----------------------
oSIST prEN ISO 11691:2019
ISO/DIS 11691:2019(E)
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 3741, Acoustics — Determination of sound power levels and sound energy levels of noise sources using
sound pressure — Precision methods for reverberation test rooms
ISO 3743-1, Acoustics — Determination of sound power levels and sound energy levels of noise sources
using sound pressure — Engineering methods for small movable sources in reverberant fields — Part 1:
Comparison method for a hard-walled test room
ISO 3744, 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 5725-2, Accuracy (trueness and precision) of measurement methods and results — Part 2: Basic method
for the determination of repeatability and reproducibility of a standard measurement method
ISO 7235, Acoustics — Laboratory measurement procedures for ducted silencers and air-terminal units —
Insertion loss, flow noise and total pressure loss
ISO 9614-2, Acoustics — Determination of sound power levels of noise sources using sound intensity —
Part 2: Measurement by scanning
IEC 60942, Sound calibrators
IEC 61183, Electroacoustics — Random-Incidence and Diffuse-Field Calibration of Sound Level
MetersIEC 61260‑1, Electroacoustics — Octave‑band and fract
...
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