EN ISO 10534-2:2023

Acoustics - Determination of acoustic properties in impedance tubes - Part 2: Two-microphone technique for normal sound absorption coefficient and normal surface impedance (ISO 10534-2:2023)

This test method covers the use of an impedance tube, two microphone locations and a frequency
analysis system for the determination of the sound absorption coefficient of sound absorbing materials
for normal incidence sound incidence. It can also be applied for the determination of the acoustical
surface impedance or surface admittance of sound absorbing materials. As an extension, it can also be
used to assess intrinsic properties of homogeneous acoustical materials such as their characteristic
impedance, characteristic wavenumber, dynamic mass density and dynamic bulk modulus.
The test method is similar to the test method specified in ISO 10534-1[1] in that it uses an impedance
tube with a sound source connected to one end and the test sample mounted in the tube at the other
end. However, the measurement technique is different. In this test method, plane waves are generated
in a tube by a sound source, and the decomposition of the interference field is achieved by the
measurement of acoustic pressures at two fixed locations using wall-mounted microphones or an intube
traversing microphone, and subsequent calculation of the complex acoustic transfer function and
quantities reported in the previous paragraph. The test method is intended to provide an alternative,
and generally much faster, measurement technique than that of ISO 10534-1[1].
Normal incidence absorption coefficients coming from impedance tube measurements are not
comparable with random incidence absorption coefficients measured in reverberation rooms according
to ISO 354[2]. The reverberation room method will (under ideal conditions) determine the sound
absorption coefficient for diffuse sound incidence. However, the reverberation room method requires
test specimens which are rather large. The impedance tube method is limited to studies at normal and
plane incidence and requires samples of the test object which are of the same size as the cross-section
of the impedance tube. For materials that are locally reacting only, diffuse incidence sound absorption
coefficients can be estimated from measurement results obtained by the impedance tube method (see
Annex E).
Through the whole document, a e+ jt time convention is used.

Akustik - Bestimmung der akustischen Eigenschaften in Impedanzrohren - Teil 2: 2‑Mikrofontechnik für Schallabsorptionsgrad und Oberflächenimpedanz bei senkrechtem Einfall (ISO 10534‑2:2023)

Dieses Prüfverfahren behandelt die Bestimmung des Schallabsorptionsgrades von schallabsorbierenden Werkstoffen bei senkrechtem Schalleinfall unter Anwendung eines Impedanzrohres, zweier Mikrofonorte sowie eines Frequenzanalysesystems. Es kann auch zur Bestimmung der akustischen Oberflächenimpedanz oder Oberflächenadmittanz von schallabsorbierenden Werkstoffen angewendet werden. In Erweiterung kann es auch angewendet werden, um intrinsische Eigenschaften von homogenen akustischen Werkstoffen, wie z. B. deren charakteristische Impedanz, die charakteristische Wellenzahl, die dynamische Massendichte und den dynamischen Kompressionsmodul, zu beurteilen.
Das Prüfverfahren ist dem in ISO 10534 1 [1] festgelegten insofern ähnlich, als ein Impedanzrohr verwendet wird, an dessen einem Ende eine Schallquelle angeschlossen ist und an dessen anderem Ende der Prüfkörper befestigt wird. Das Messverfahren ist jedoch ein anderes. Bei diesem Prüfverfahren werden mit Hilfe einer Schallquelle ebene Wellen im Rohr erzeugt und die Zerlegung des Interferenzfeldes durch Messung des akustischen Druckes an zwei festen Orten erreicht, wobei an der Wand befestigte Mikrofone oder ein im Rohr verfahrbares Mikrofon verwendet werden bzw. wird; anschließend werden die komplexe akustische Übertragungsfunktion und die vorstehend genannten Größen berechnet. Dieses Prüfverfahren dient er Bereitstellung eines alternativen und im Vergleich zu dem in ISO 10534 1 [1] behandelten im Allgemeinen viel schnelleren Messverfahrens.
Die sich bei Impedanzrohrmessungen mit senkrechtem Schalleinfall ergebenden Absorptionsgrade sind nicht mit den in Hallräumen bei zufälligem Schalleinfall nach ISO 354 [2] gemessenen Absorptionsgraden vergleichbar. Mit Hilfe des Hallraumverfahrens wird (unter Idealbedingungen) der Schallabsorptionsgrad bei diffusem Schalleinfall bestimmt. Für das Hallraumverfahren werden jedoch verhältnismäßig große Probekörper benötigt. Das Impedanzrohrverfahren ist auf Untersuchungen bei senkrechtem und ebenem Schalleinfall begrenzt und erfordert Proben des Prüfgegenstandes, die die gleiche Größe wie der Querschnitt des Impedanzrohres besitzen. Bei ausschließlich lokal wirkenden Werkstoffen können die Schallabsorptionsgrade bei diffusem Einfall aus den Messergebnissen geschätzt werden, die mit dem Impedanzrohrverfahren gewonnen wurden (siehe Anhang E).
Im gesamten Dokument wird eine e^(+jωt) Zeitkonvention verwendet.

Acoustique - Détermination des propriétés acoustiques aux tubes d’impédance - Partie 2: Méthode à deux microphones pour le coefficient d’absorption acoustique normal et l’impédance de surface normale (ISO 10534-2:2023)

Akustika - Ugotavljanje akustičnih lastnosti v Kundtovi cevi - 2. del: Dvomikrofonska tehnika za določanje normalnega koeficienta absorpcije zvoka in normalne površinske impedance (ISO 10534-2:2023)

Ta preskusna metoda zajema uporabo Kundtove cevi, mest postavitve dveh mikrofonov in sistema analize frekvence za določanje koeficienta absorpcije zvoka absorpcijskih materialov za
normalni vpad zvoka. Uporabiti jo je mogoče tudi za ugotavljanje akustične površinske impedance ali površinske vpojnosti zvoka absorpcijskih materialov. V razširitvenih izvedbi jo je mogoče uporabiti tudi za ocenjevanje intrinzičnih lastnosti homogenih akustičnih materialov, npr. značilna
impedanca, značilno valovno število, dinamična masna gostota in dinamični stisljivostni modul.
Preskusna metoda je podobna tisti, določeni v standardu ISO 10534-1[1], in sicer v uporabi Kundtove cevi z virom zvoka, povezanim na en konec cevi, in preskusnim vzorcem, nameščenim na drug konec cevi. Vseeno pa metodi uporabljata različno merilno tehniko. Ravne valove v cevi pri tej preskusni metodi ustvarja
vir zvoka, razgradnja interferenčnega polja pa nastane z merjenjem zvočnih tlakov na dveh določenih lokacijah, in sicer z uporabo stenskih mikrofonov oziroma prehodnega mikrofona v cevi, in nadaljnjim izračunom kompleksne funkcije prenosa zvoka in količin iz prejšnjega odstavka. Ta preskusna metoda je namenjena zagotavljanju alternative
in je običajno precej hitrejša merilna tehnika v primerjavi s tisto iz standarda ISO 10534-1[1].
Normalni koeficienti absorpcije pojavnosti iz merjenja Kundtove cevi niso primerljivi z naključnimi koeficient absorpcije pojavnosti, merjenimi v odmevnicah v skladu s standardom ISO 354[2]. Metoda odmevnice bo (v idealnih pogojih) določila koeficient absorpcije zvoka za pojav difuznega zvoka. Vendar pa je treba pri metodi odmevnice uporabiti sorazmerno velike preskušance. Metoda Kundtove cevi je omejena na študije normalne in ravninske pojavnosti in zahteva vzorce predmeta preskusa, ki so enako veliki kot presek Kundtove cevi. Za materiale, ki reagirajo samo lokalno, je mogoče koeficiente absorpcije pojavnosti difuznega zvoka oceniti iz rezultatov merjenja z metodo Kundtove cevi (glej dodatek E).
V celotnem dokumentu se uporablja konvencija o času a e+ j t.

General Information

• Status: Published
• Publication Date: 10-Oct-2023
• ICS: 17.140.01 - Acoustic measurements and noise abatement in general
• Technical Committee: CEN/TC 126 - Acoustic properties of building products and of buildings
• Drafting Committee: CEN/TC 126/WG 1 - Methods for measuring the sound insulation of building elements and the acoustic performances of buildings
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 11-Oct-2023
• Completion Date: 11-Oct-2023
• Ref Project: SIST EN ISO 10534-2:2024 - Acoustics - Determination of acoustic properties in impedance tubes - Part 2: Two-microphone technique for normal sound absorption coefficient and normal surface impedance (ISO 10534-2:2023)

Relations

• Replaces: EN ISO 10534-2:2001 - Acoustics - Determination of sound absorption coefficient and impedance in impedances tubes - Part 2: Transfer-function method (ISO 10534-2:1998)
• Effective Date: 30-Sep-2020

Standards Content (Sample)

SLOVENSKI STANDARD
01-februar-2024
Nadomešča:
SIST EN ISO 10534-2:2002
Akustika - Ugotavljanje akustičnih lastnosti v Kundtovi cevi - 2. del:
Dvomikrofonska tehnika za določanje normalnega koeficienta absorpcije zvoka in
normalne površinske impedance (ISO 10534-2:2023)
Acoustics - Determination of acoustic properties in impedance tubes - Part 2: Two-
microphone technique for normal sound absorption coefficient and normal surface
impedance (ISO 10534-2:2023)
Akustik - Bestimmung der akustischen Eigenschaften in Impedanzrohren - Teil 2: 2-
Mikrofontechnik für Schallabsorptionsgrad und Oberflächenimpedanz bei senkrechtem
Einfall (ISO 10534-2:2023)
Acoustique - Détermination des propriétés acoustiques aux tubes d’impédance - Partie
2: Méthode à deux microphones pour le coefficient d’absorption acoustique normal et
l’impédance de surface normale (ISO 10534-2:2023)
Ta slovenski standard je istoveten z: EN ISO 10534-2:2023
ICS:
17.140.01 Akustična merjenja in Acoustic measurements and
blaženje hrupa na splošno noise abatement in general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 10534-2
EUROPEAN STANDARD
NORME EUROPÉENNE
October 2023
EUROPÄISCHE NORM
ICS 17.140.01 Supersedes EN ISO 10534-2:2001
English Version
Acoustics - Determination of acoustic properties in
impedance tubes - Part 2: Two-microphone technique for
normal sound absorption coefficient and normal surface
impedance (ISO 10534-2:2023)
Acoustique - Détermination des propriétés acoustiques Akustik - Bestimmung der akustischen Eigenschaften
aux tubes d'impédance - Partie 2: Méthode à deux in Impedanzrohren - Teil 2: 2-Mikrofontechnik für
microphones pour le coefficient d'absorption Standardschallabsorptionsgrad und
acoustique normal et l'impédance de surface normale Standardoberflächenimpedanz (ISO 10534-2:2023)
(ISO 10534-2:2023)
This European Standard was approved by CEN on 2 October 2023.

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, Türkiye 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
© 2023 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 10534-2:2023 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 10534-2:2023) has been prepared by Technical Committee ISO/TC 43
"Acoustics" in collaboration with Technical Committee CEN/TC 126 “Acoustic properties of building
elements 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 April 2024, and conflicting national standards shall be
withdrawn at the latest by April 2024.
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 10534-2:2001.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN website.
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, Türkiye and the
United Kingdom.
Endorsement notice
The text of ISO 10534-2 has been approved by CEN as EN ISO 10534-2:2023 without any modification.

INTERNATIONAL ISO
STANDARD 10534-2
Second edition
2023-10
Acoustics — Determination of acoustic
properties in impedance tubes —
Part 2:
Two-microphone technique for
normal sound absorption coefficient
and normal surface impedance
Acoustique — Détermination des propriétés acoustiques aux tubes
d’impédance —
Partie 2: Méthode à deux microphones pour le coefficient d’absorption
sonore normal et l’impédance de surface normale
Reference number
ISO 10534-2:2023(E)
ISO 10534-2:2023(E)
© ISO 2023
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: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
ISO 10534-2:2023(E)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms, definitions and symbols . 1
4 Principle . 5
5 Test equipment .5
5.1 Construction of the impedance tube . 5
5.2 Working frequency range . 6
5.3 Length of the impedance tube . 7
5.4 Microphones . 7
5.5 Positions of the microphones . 7
5.6 Acoustic centre of the microphone . 8
5.7 Test sample holder. 8
5.8 Signal processing equipment . 9
5.9 Loudspeaker . 9
5.10 Signal generator. 9
5.11 Thermometer, barometer and relative humidity . 9
6 Preliminary test and measurements .10
7 Test specimen mounting .11
8 Test procedure .12
8.1 Specification of the reference plane .12
8.2 Determination of the sound velocity, wavelength and characteristic impedance .12
8.3 Selection of the signal amplitude . 13
8.4 Selection of the number of averages . 13
8.5 Correction for microphone mismatch . 13
8.5.1 General .13
8.5.2 Measurement repeated with the channels interchanged .13
8.5.3 Predetermined calibration factor . 14
8.6 Determination of the transfer function between the two locations .15
8.6.1 General .15
8.6.2 Cross- and autospectra-based estimate . 15
8.6.3 Frequency-domain deconvolution . 17
8.6.4 Impulse-response based estimate . 17
8.7 Determination of the reflection coefficient . 18
8.8 Determination of the sound absorption coefficient . 18
8.9 Determination of the specific acoustic impedance ratio . 18
8.10 Determination of the specific acoustic admittance ratio . 18
9 Precision .19
10 Test report .19
Annex A (normative) Preliminary measurements .22
Annex B (normative) Procedure for the one-microphone technique .24
Annex C (informative) Theoretical background .25
Annex D (informative) Error sources .27
Annex E (informativ
...