EN ISO 10534-1:2001

SLOVENSKI STANDARD
01-december-2002
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Acoustics - Determination of sound absorption coefficient and impedance in impedances
tubes - Part 1: Method using standing wave ratio (ISO 10534-1:1996)
Akustik - Bestimmung des Schallabsorptionsgrades und der Impedanz in
Impedanzrohren - Teil 1: Verfahren mit Stehwellenverhältnis (ISO 10534-1:1996)
Acoustique - Détermination du facteur d'absorption acoustique et de l'impédance
acoustique a l'aide du tube d'impédance - Partie 1: Méthode du taux d'ondes
stationnaires (ISO 10534-1:1996)
Ta slovenski standard je istoveten z: EN ISO 10534-1:2001
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 10534-1
NORME EUROPÉENNE
EUROPÄISCHE NORM
June 2001
ICS 17.140.01
English version
Acoustics - Determination of sound absorption coefficient and
impedance in impedances tubes - Part 1: Method using standing
wave ratio (ISO 10534-1:1996)
Acoustique - Détermination du facteur d'absorption Akustik - Bestimmung des Schallabsorptionsgrades und
acoustique et de l'impédance acoustique à l'aide du tube der Impedanz in Impedanzrohren - Teil 1: Verfahren mit
d'impédance - Partie 1: Méthode du taux d'ondes Stehwellenverhältnis (ISO 10534-1:1996)
stationnaires (ISO 10534-1:1996)
This European Standard was approved by CEN on 13 May 2001.
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 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 Management Centre has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,
Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2001 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 10534-1:2001 E
worldwide for CEN national Members.

Page 2
Foreword
The text of the International Standard from Technical Committee ISO/TC 43 "Acoustics" of the
International Organization for Standardization (ISO) has been taken over as an European Standard
by Technical Committee CEN/TC 126 "Acoustic properties of building products and of buildings", the
secretariat of which is held by AFNOR.
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 December 2001, and conflicting national standards
shall be withdrawn at the latest by December 2001.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Czech
Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg,
Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom.
Endorsement notice
The text of the International Standard ISO 10534-1:1996 has been approved by CEN as a European
Standard without any modification.
NOTE: Normative references to International Standards are listed in annex ZA (normative).

Page 3
Annex ZA
(normative)
Normative references to international publications with their relevant European
publications
This European Standard incorporates by dated or undated reference, provisions from other
publications. These normative references are cited at the appropriate places in the text and the
publications are listed hereafter. For dated references, subsequent amendments to or revisions
of any of these publications apply to this European Standard only when incorporated in it by
amendment or revision. For undated references the latest edition of the publication referred to
applies (including amendments).
NOTE Where an International Publication has been modified by common modifications, indicated by
(mod.), the relevant EN/HD applies.
Publication Year Title EN/HD Year
ISO 266 1975 Acoustics - Preferred frequencies for EN ISO 266 1997
measurements
Acoustics - Measurement of sound insulation prEN ISO 354 2000
ISO 354 1985
in a reverbaration room
INTERNATIONAL
IS0
STANDARD
10534-l
First edition
1996-I 2-l 5
Acoustics - Determination of sound
absorption coefficient and impedance in
impedance tubes -
Part 1:
Method using standing wave ratio
Acoustique -
Dgtermination du facteur d’absorption acoustique et
de /‘imp&dance acoustique a I’aide du tube d/imp&dance -
Partie 1: M&hode du taux d’ondes stationnaires
Reference number
IS0 10534-I : 1996(E)
IS0 10534=1:1996(E)
Page
Contents
...........................................................................................
1 Scope
Normative references .
Definitions .
4 Principle .
..............................................................................
5 Fundamentals
...........................................................................
6 Test equipment
IO
..........................................
7 Preliminary tests and measurements
IO
.......................................................
8 Mounting of the test sample
IO
..............................................................................
9 Test methods
.................... 11
10 Transformation of reflection factor and impedance
...................................................................................
11 Test report
Annexes
A Preliminary measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6 Verification of the test equipment
C Pressure-release termination of test sample . . . . . . . . . . . . . . . . .I.
D Determination of diffuse sound absorption coefficient a,, of
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
locally reacting absorbers
0 IS0 1996
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
IS0 10534=1:1996(E)
@ IS0
Foreword
IS0 (the International Organization for Standardization) is a worldwide fed-
eration 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 10534-I was prepared by Technical Committee
lSO/TC 43, Acoustics, Subcommittee SC 2, Building acoustics.
IS0 10534 consists of the following parts, under the general title Acous-
tics - Determination of sound absorption coefficient and impedance in
impedance tubes:
Part 1: Method using standing wave ratio
- Part 2: Method using two microphones
Annexes A, B and C form an integral part of this part of IS0 10534.
Annex D is for information only.

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INTERNATIONAL STANDARD @ IS0 IS0 10534=1:1996(E)
Acoustics - Determination of sound absorption coefficient and
impedance in impedance tubes -
Part 1:
Method using standing wave ratio
Sound absorption coefficients exceeding the value 1
1 Scope
are therefore sometimes obtained.
1.1 This part of IS0 10534 specifies a method for
The impedance tube method requires samples of the
the determination of the sound absorption coefficient,
test object which are the size of the cross-sectional
reflection factor and surface impedance or surface
area of the impedance tube. The reverberation room
admittance of materials and objects. The values are
method requires test objects which are rather large
determined for normal sound incidence by evaluation
and can also be applied to test objects with pro-
of the standing wave pattern of a plane wave in a
nounced structures in the lateral and/or normal direc-
tube, which is generated by the superposition of an
tions. Measurements with such objects in the
incident sinusoidal plane wave with the plane wave
impedance tube must be interpreted with care
reflected from the test object.
(see 9.1).
This method can be used for the determination of the
For the computational transformation of the test re-
sound absorption coefficient of sound absorbers for
sults from the impedance tube method (normal inci-
normal sound incidence. It can further be used for the
dence) to the situation of diffuse sound incidence, see
determination of the acoustical surface impedance or
annex D.
surface admittance of sound-absorbing materials. It is
well suited for parameter studies and for the design of
I.3 This part of IS0 10534 gives preference to nu-
sound absorbers, because only small samples of the
merical methods of evaluation instead of graphical
absorber material are needed.
methods, because computers which can perform
these computations are assumed to be available.
Some of the quantities in the formulae are complex.
1.2 There are some characteristic differences be-
The arguments of trigonometric functions are in
tween this method and the measurement of sound
radians.
absorption in a reverberation room (see IS0 354).
The impedance tube method can be used for the de-
termination of the reflection factor and also the im-
2 Normative references
pedance or admittance. The sound is incident normally
on the object surface. The reverberation room method
will (under idealized conditions) determine the sound
The following standards contain provisions which,
absorption coefficient for random sound incidence.
through reference in this text, constitute provisions of
this part of IS0 10534. At the time of publication, the
The impedance tube method relies on the existence editions indicated were valid. All standards are subject
of a plane incident sound wave and gives exact values to revision, and parties to agreements based on this
under this condition (measuring and mounting errors
part of IS0 10534 are encouraged to investigate the
excluded). The evaluation of the sound absorption co- possibility of applying the most recent editions of the
efficient in a reverberation room is based on a number
standards indicated below. Members of IEC and IS0
of simplifying and approximate assumptions concern-
maintain registers of currently valid International Stan-
ing the sound field and the size of the absorber. dards.

@ IS0
IS0 10534=1:1996(E)
IS0 266:- 1), Acoustics - Preferred frequencies. 3.10 normalized impedance, Z: Ratio of the imped-
ance Z to the characteristic impedance ZO:
IS0 354:1985, Acoustics - Measurement of sound
absorption in a reverberation room. 2 = z/z,
3.11 normalized admittance, g: Product of the
admittance G and the characteristic impedance ZO:
3 Definitions
g = ZoG
For the purposes of this part of IS0 10534, the follow-
3.12 standing wave ratio, S: Ratio of the sound
ing definitions apply.
pressure amplitude at a pressure maximum, lpmax I,
3.1 sound absorption coefficient, a: Ratio of the
to that at an adjacent pressure minimum, lpmin 1 (if
sound power entering the surface of the test object
necessary after correction for varying values at the
(without return) to the incident sound power for a
minima due to sound attenuation in the impedance
plane wave at normal incidence.
tube):
3.2 sound pressure reflection factor at normal
incidence, r: Complex ratio of the pressure amplitude
of the reflected wave to the incident wave in the refer-
3.13 standing wave ratio with attenuation, s,:
ence plane for a plane wave at normal incidence.
Standing wave ratio of the nth maximum to the lath
minimum.
3.3 reference plane: Cross-section of the imped-
ance tube for which the reflection factor I- or the im-
3.14 free-field wave number, kO:
pedance 2 or the admittance G are determined and
which is usually the surface of flat test objects. It is
k. = m/c, = 2Tcflco
assumed to be at x = 0.
3.4 field impedance, Z(X): Ratio of the sound press-
w is the angular frequency;
...