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1、BRITISH STANDARD BS EN ISO 10534-2:2001 Incorporating Amendment No. 1 to BS ISO 10534-2:1998 (renumbers the BS ISO as BS EN ISO 10534-2:2001) Acoustics Determination of sound absorption coefficient and impedance in impedance tubes Part 2: Transfer-function method The European Standard EN ISO 10534-2
2、:2001 has the status of a British Standard ICS 17.140.01 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Licensed Copy: sheffieldun sheffieldun, na, Sat Nov 18 06:44:08 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN ISO 10534-2:2001 This British Standard, having been prepare
3、d under the direction of the Health and Environment Sector Committee, was published under the authority of the Standards Committee and comes into effect on 15 May 1999 BSI 11 April 2002 ISBN 0 580 32462 1 National foreword This British Standard is the official English language version of EN ISO 1053
4、4-2:2001. It is identical with ISO 10534-2:1998. The UK participation in its preparation was entrusted by Technical Committee EH/1, Acoustics, to Subcommittee EH/1/6, Building acoustics, which has the responsibility to: A list of organizations represented on this subcommittee can be obtained on requ
5、est to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of t
6、he BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. ai
7、d enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages Th
8、is document comprises a front cover, an inside front cover, the EN ISO title page, the EN ISO foreword page, the ISO title page, pages ii to iv, pages 1 to 23 and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. Amendments issued since pu
9、blication Amd. No.DateComments 1370111 April 2002Implementation of the European Standard Licensed Copy: sheffieldun sheffieldun, na, Sat Nov 18 06:44:08 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 10534-2 June 2001 ICS 17.140.01 English version
10、 Acoustics Determination of sound absorption coefficient and impedance in impedances tubes Part 2: Transfer-function method (ISO 10534-2:1998) Acoustique Dtermination du facteur dabsorption acoustique et de limpdance des tubes dimpdance Partie 2: Mthode de la fonction de transfert (ISO 10534-2:1998)
11、 Bauakustik Bestimmung des Schallabsorptionsgrades und der Impedanz in Impedanzrohren Teil 2: Verfahren mit bertragungsfunktion (ISO 10534-2:1998) 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
12、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 thr
13、ee 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 Aust
14、ria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Managem
15、ent Centre: rue de Stassart, 36 B-1050 Brussels 2001 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 10534-2:2001 E Licensed Copy: sheffieldun sheffieldun, na, Sat Nov 18 06:44:08 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN I
16、SO 10534-2:2001 BSI 11 April 2002 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
17、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 la
18、test 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, N
19、etherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. Licensed Copy: sheffieldun sheffieldun, na, Sat Nov 18 06:44:08 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Licensed Copy: sheffieldun sheffieldun, na, Sat Nov 18 06:44:08 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN IS
20、O 10534-2:2001 ii BSI 11 April 2002 Contents Page Forewordiii 1Scope1 2Definitions and symbols1 3Principle3 4Test equipment3 5Preliminary test and measurements7 6Test specimen mounting8 7Test procedure8 8Precision13 9Test report13 Annex A (normative) Preliminary measurements14 Annex B (normative) Pr
21、ocedure for the one-microphone technique19 Annex C (normative) Pressure-release termination of test sample19 Annex D (informative) Theoretical background20 Annex E (informative) Error sources21 Annex F (informative) Determination of diffuse sound absorption coefficient ?st of locally reacting absorb
22、ers from the results of this part of ISO 1053423 Annex G (informative) Bibliography23 Figure 1 Examples of typical microphone mounting5 Figure 2 Microphone positions and distances5 Figure 3 Example of layout for test equipment7 Figure 4 Standard configuration (configuration I)10 Figure 5 Configurati
23、on with microphones interchanged (configuration II)10 Figure A.1 Tube attenuation correction17 Figure A.2 Determination of the acoustic centre of a probe microphone18 Descriptors: Acoustics, acoustic absorption, sound absorbers, tests, acoustic tests, determination, sound absorption coefficient, aco
24、ustic measurements. Licensed Copy: sheffieldun sheffieldun, na, Sat Nov 18 06:44:08 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN ISO 10534-2:2001 BSI 11 April 2002 iii Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO membe
25、r 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, governmenta
26、l 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 membe
27、r bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. International Standard ISO 10534-2 was prepared by Technical Committee ISO/TC 43, Acoustics, Subcommittee SC 2, Building acoustics. ISO 10534 consists of the followin
28、g parts, under the general title Acoustics Determination of sound absorption coefficient and impedance in impedance tubes: Part 1: Method using standing wave ratio; Part 2: Transfer-function method. Annex A, Annex B and Annex C form an integral part of this part of ISO 10534. Annex D, Annex E, Annex
29、 F and Annex G are for information only. Licensed Copy: sheffieldun sheffieldun, na, Sat Nov 18 06:44:08 GMT+00:00 2006, Uncontrolled Copy, (c) BSI iv blank Licensed Copy: sheffieldun sheffieldun, na, Sat Nov 18 06:44:08 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN ISO 10534-2:2001 BSI 11 April 200
30、2 1 1 Scope This test method covers the use of an impedance tube, two microphone locations and a digital frequency analysis system for the determination of the sound absorption coefficient of sound absorbers for normal sound incidence. It can also be applied for the determination of the acoustical s
31、urface impedance or surface admittance of sound absorbing materials. Since the impedance ratios of a sound absorptive material are related to its physical properties, such as airflow resistance, porosity, elasticity and density, measurements described in this test method are useful in basic research
32、 and product development. The test method is similar to the test method specified in ISO 10534-1 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,
33、plane waves are generated in a tube by a noise 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 in-tube traversing microphone, and subsequent calculation of the complex acoustic tr
34、ansfer function, the normal incidence absorption and the impedance ratios of the acoustic material. The test method is intended to provide an alternative, and generally much faster, measurement technique than that of ISO 10534-1. Compared with the measurement of the sound absorption in a reverberati
35、on room according to the method specified in ISO 354, there are some characteristic differences. The reverberation room method will (under ideal conditions) determine the sound absorption coefficient for diffuse sound incidence, and the method can be used for testing of materials with pronounced str
36、uctures in the lateral and normal directions. However, the reverberation room method requires test specimens which are rather large, so it is not convenient for research and development work, where only small samples of the absorber are available. The impedance tube method is limited to parametric s
37、tudies at normal incidence but 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, diffuse incidence sound absorption coefficients can be estimated from measurement results obtained by the impedance tube
38、method. For transformation of the test results from the impedance tube method (normal incidence) to diffuse sound incidence, see Annex F. 2 Definitions and symbols For the purposes of this part of ISO 10534 the following definitions apply. 2.1 sound absorption coefficient at normal incidence ? ratio
39、 of sound power entering the surface of the test object (without return) to the incident sound power for a plane wave at normal incidence 2.2 sound pressure reflection factor at normal incidence r complex ratio of the amplitude of the reflected wave to that of the incident wave in the reference plan
40、e for a plane wave at normal incidence 2.3 reference plane cross-section of the impedance tube for which the reflection factor r or the impedance Z or the admittance G are determined and which is usually the surface of the test object, if flat NOTEThe reference plane is assumed to be at x = 0. 2.4 n
41、ormal surface impedance Z ratio of the complex sound pressure p(0) to the normal component of the complex sound particle velocity v(0) at an individual frequency in the reference plane Licensed Copy: sheffieldun sheffieldun, na, Sat Nov 18 06:44:08 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN ISO 1
42、0534-2:2001 2 BSI 11 April 2002 2.5 normal surface admittance G inverse of the normal surface impedance Z 2.6 wave number k0 variable defined by k0 = ?/c0 = 2?f/c0 NOTEIn general the wave number is complex, so k0 = k0? jk0? 2.7 complex sound pressure p Fourier transform of the temporal acoustic pres
43、sure 2.8 cross spectrum S12 product p2p1*, determined from the complex sound pressures p1 and p2 at two microphone positions NOTE* means the complex conjugate. 2.9 auto spectrum S11 product p1p1*, determined from the complex sound pressure p1 at microphone position one NOTE* means the complex conjug
44、ate. 2.10 transfer function H12 transfer function from microphone position one to two, defined by the complex ratio p2/p1 = S12/S11 or S22/S21, or (S12/S11)(S22/S21)1/2 2.11 calibration factor Hc factor used to correct for amplitude and phase mismatches between the microphones NOTESee 7.5.2. where ?
45、is the angular frequency; fis the frequency; c0is the speed of sound. where k0?is the real component (k0? = 2?/?0); ?0is the wavelength; k0?is the imaginary component which is the attenuation constant, in nepers per metre. Licensed Copy: sheffieldun sheffieldun, na, Sat Nov 18 06:44:08 GMT+00:00 200
46、6, Uncontrolled Copy, (c) BSI EN ISO 10534-2:2001 BSI 11 April 2002 3 3 Principle The test sample is mounted at one end of a straight, rigid, smooth and airtight impedance tube. Plane waves are generated in the tube by a sound source (random, pseudo-random sequence, or chirp), and the sound pressure
47、s are measured at two locations near to the sample. The complex acoustic transfer function of the two microphone signals is determined and used to compute the normal-incidence complex reflection factor (see Annex C), the normal-incidence absorption coefficient, and the impedance ratio of the test ma
48、terial. The quantities are determined as functions of the frequency with a frequency resolution which is determined from the sampling frequency and the record length of the digital frequency analysis system used for the measurements. The usable frequency range depends on the width of the tube and th
49、e spacing between the microphone positions. An extended frequency range may be obtained from the combination of measurements with different widths and spacings. The measurements may be performed by employing one of two techniques: 4 Test equipment 4.1 Construction of the impedance tube The apparatus is essentially a tube with a test sample holder at one end and a sound source at the other. Microphone ports are usually located at two or three locations along the wall of the tube, but variations involving a c
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