BS EN 29053-1993 Acoustics - Materials for acoustical applications - Determination of airflow resistance《声学 声学用材料 气流阻尼的测定》.pdf

1、BRITISH STANDARD BS EN 29053:1993 ISO9053:1991 Acoustics Materials for acoustical applications Determination of airflow resistance The European Standard EN29053:1993 has the status of a BritishStandard UDC 699.844-405.8:534.833:620.1:533.6.011.3BSEN29053:1993 This BritishStandard, having been prepar

2、ed under the directionof the Environment andPollution Standards PolicyCommittee, was publishedunder the authorityofthe Standards Boardand comes into effect on 15May1993 BSI12-1999 The following BSI references relate to the work on this standard: Committee reference EPC/1 Draft for comment88/56272 DC

3、 ISBN 0 580 21966 6 Cooperating organizations The European Committee for Standardization (CEN), under whose supervision this European Standard was prepared, comprises the national standards organizations of the following countries: Austria Oesterreichisches Normungsinstitut Belgium Institut belge de

4、 normalisation Denmark Dansk Standardiseringsraad Finland Suomen Standardisoimisliito, r.y. France Association franaise de normalisation Germany Deutsches Institut fr Normung e.V. Greece Hellenic Organization for Standardization Iceland Technological Institute of Iceland Ireland National Standards A

5、uthority of Ireland Italy Ente Nazionale Italiano di Unificazione Luxembourg Inspection du Travail et des Mines Netherlands Nederlands Normalisatie-instituut Norway Norges Standardiseringsforbund Portugal Instituto Portugus da Qualidade Spain Asociacin Espaola de Normalizacin y Certificacin Sweden S

6、tandardiseringskommissionen i Sverige Switzerland Association suisse de normalisation United Kingdom BritishStandards Institution Amendments issued since publication Amd. No. Date CommentsBSEN29053:1993 BSI 12-1999 i Contents Page Cooperating organizations Inside front cover National foreword ii For

7、eword 2 1 Scope 3 2 Definitions 3 3 Principle 3 4 Equipment 3 5 Test specimens 8 6 Test procedure 9 7 Precision 9 8 Test report 9 Annex A (informative) Bibliography 10 National annex NA (informative) Committees responsible Inside back cover Figure 1 Direct airflow method (method A) Basic principle 4

8、 Figure 2 Alternating airflow method (method B) Basic principle 4 Figure 3 Measurement equipment, with cylindrical section, for direct airflow method (method A) 5 Figure 4 Measurement cell with specimen holder for measuring fibre materials of loose and wadding structure (method B) 7 Figure 5 Measure

9、ment cell with holder for cylindrical specimen (method B) 8BSEN29053:1993 ii BSI 12-1999 National foreword This BritishStandard has been prepared under the direction of the Environment and Pollution Standards Policy Committee. It is the English language version of EN29053:1993 Acoustics Materials fo

10、r acoustical applications Determination of airflow resistance, published by the European Committee for Standardization (CEN). It is identical with ISO9053:1991, published by the International Organization for Standardization (ISO). The airflow resistance of porous materials indicates, in an indirect

11、 manner, some of their structural properties. It may be used to establish correlations between structure of these materials and some of their acoustical properties (for example, absorption, attenuation, etc.). This BritishStandard is, therefore, useful for two purposes: a) relating some of the acous

12、tical properties of porous materials to their structure and their method of manufacture; b) ensuring product quality (quality control). 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.

13、 Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, theEN title page, pages2 to10, an inside back cover and a back cover. This standard has been updated (see copy

14、right date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN29053 March1993 UDC 699.844-405.8:534.833:620.1:533.6.011.3 Descriptors: Acoustics, acoustic insulation, insulating materi

15、als acoustic, porous materials, gas permeability tests, air flow English version Acoustics Materials for acoustical applications Determination of airflow resistance (ISO9053:1991) Acoustique Matriaux pour applications acoustiques Dtermination de la rsistance lcoulement de lair (ISO9053:1991) Akustik

16、 Materialien fr akustische Anwendungen Bestimmung des Strmungswiderstandes (ISO9053:1991) This European Standard was approved by CEN1993-02-12. 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 n

17、ational standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in

18、 any other language made by translation under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Denmark, Finland, France, Germany, Greece, I

19、celand, 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 Central Secretariat: rue de Stassart 36, B-1050 Brussels 1993 Copyright reserved

20、to CEN members Ref. No. EN29053:1993 EEN29053:1993 BSI 12-1999 2 Foreword Following the positive result of the primary questionnaire, CEN Technical Board decided to submit ISO9053:1991 Acoustics Materials for acoustical applications Determination of airflow resistance to the formal vote. The result

21、was positive. 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 September1993, and conflicting national standards shall be withdrawn at the latest by September1993. In accordance with the CEN/CENELE

22、C Internal Regulations, the following countries are bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.EN29053:1993 BSI 12-1999 3 1 S

23、cope This International Standard specifies two methods for the determination of the airflow resistance of porous materials for acoustical applications. It is applicable to test specimens cut from products of porous materials. NOTE 1Details of publications relating to flow behaviour under both lamina

24、r and turbulent conditions are given in Annex A. 2 Definitions For the purposes of this International Standard, the following definitions apply. 2.1 airflow resistance, R a quantity defined by it is expressed in pascal seconds per cubic metre 2.2 specific airflow resistance, R s a quantity defined b

25、y R s = RA it is expressed in pascal seconds per metre 2.3 airflow resistivity, r if the material is considered as being homogeneous, that quantity defined by it is expressed in pascal seconds per square metre 2.4 linear airflow velocity, u a quantity defined by it is expressed in metres per second

26、3 Principle 3.1 Direct airflow method (method A) Passing of a controlled unidirectional airflow through a test specimen in the form of a circular cylinder or a rectangular parallelepiped, and measurement of the resulting pressure drop between the two free faces of the test specimen (seeFigure 1). 3.

27、2 Alternating airflow method (method B) Passing of a slowly alternating airflow through a test specimen in the form of a circular cylinder or a rectangular parallelepiped, and measurement of the alternating component of the pressure in a test volume enclosed by the specimen (see Figure 2). 4 Equipme

28、nt 4.1 Equipment for method A The equipment shall consist of a) a measurement cell into which the test specimen is placed; b) a device for producing a steady airflow; c) a device for measuring the volumetric airflow rate; d) a device for measuring the pressure difference across the test specimen; e)

29、 a device for measuring the thickness of the test specimen when it is in position for the test. An example of suitable equipment is shown in Figure 3. 4.1.1 Measurement cell The measurement cell shall be in the shape of a circular cylinder or a rectangular parallelepiped. An example of a cylindrical

30、 measurement cell is shown in Figure 3. If it is circular in cross-section, the internal diameter shall be greater than95mm. where %p is the air pressure difference, in pascals, across the test specimen with respect to the atmosphere; q v is the volumetric airflow rate, in cubic metres per second, p

31、assing through the test specimen. where R is the airflow resistance, in pascal seconds per cubic metre, of the test specimen; A is the cross-sectional area, in square metres, of the test specimen perpendicular to the direction of flow. where R s is the specific airflow resistance, in pascal seconds

32、per metre, of the test specimen; d is the thickness, in metres, of the test specimen in the direction of flow. R %p q v - = r R s d - = where q v is the volumetric airflow rate, in cubic metres per second, passing through the test specimen; A is the cross-sectional area, in square metres, of the tes

33、t specimen. u q v A - =EN29053:1993 4 BSI 12-1999 Figure 1 Direct airflow method (method A) Basic principle Figure 2 Alternating airflow method (method B) Basic principleEN29053:1993 BSI 12-1999 5 For the rectangular parallelepiped shape, the preferred cross-section is a square. In any case, all sid

34、es shall measure at least90mm. The total height of the cell should be such that there is essentially laminar undirectional airflow entering and leaving the test specimen. The height should be at least100mm greater than the thickness of the test specimen. The test specimen shall rest inside the measu

35、rement cell (on a perforated support if necessary), positioned far enough above the base of the cell to meet the above requirement. This support shall have a minimum open area of50%, evenly distributed. The holes in the support shall have a diameter not less than3mm. NOTE 2In some cases it may be ne

36、cessary to increase the percentage of the open area in order not to restrict the airflow through the test specimen. The tapping points for the measurement of pressure and airflow shall be leak-free and arranged below the level of the perforated support. 4.1.2 Device for producing airflow It is recom

37、mended that pressure depression systems of the water reservoir or vacuum pump type be used. Alternatively, pressurization systems (air compressor, etc.) may be used if they do not contaminate the air. Whatever airflow source is used, the installation shall permit fine control of the flow and shall e

38、nsure the stability of the flow in the lower part of the test cell. The airflow source should provide airflow rates such that the resulting velocities will be low enough to ensure that the measured airflow resistances are independent of velocity. It is recommended that the source be such as to permi

39、t airflow velocities down to0,5 10 3 m/s to be obtained. 4.1.3 Device for measuring volumetric airflow rate The pressure tap of the instrument for measuring the volumetric airflow rate shall be placed between the source and the test specimen, inside the test cell as close as possible to the test spe

40、cimen. Figure 3 Measurement equipment, with cylindrical section, for direct airflow method (method A)EN29053:1993 6 BSI 12-1999 The arrangement used shall permit measurement of the airflow to an accuracy of 5% of the indicated value. 4.1.4 Device for measuring differential pressure The equipment use

41、d for measuring differential pressures shall permit measurements of pressures as low as0,1Pa. The arrangement used shall permit measurement of the differential pressure to an accuracy of 5% of the indicated value. 4.2 Equipment for method B The equipment shall consist of a) a measurement cell into w

42、hich the test specimen is placed; b) a device for producing an alternating airflow; c) a device for measuring the alternating component of the pressure in the test volume enclosed by the test specimen; d) a device for measuring the thickness of the test specimen when it is in position for the test.

43、Two examples of suitable equipment with different specimen holders are shown in Figure 4 and Figure 5. 4.2.1 Measurement cell The measurement cell is composed of two parts: a) the specimen holder; b) the test volume (see Figure 4 and Figure 5). Both parts shall be in the shape of a circular cylinder

44、, as shown in Figure 4 and Figure 5, or a rectangular parallelepiped. If the shape of the specimen holder is circular in cross-section, the internal diameter shall be greater than95mm. For rectangular specimen holders, the preferred cross-section is a square. In any case, all sides shall measure at

45、least90mm. In all cases, the test volume shall have a cross-section equal to at least that of the specimen holder. The test specimen shall rest inside the specimen holder (on a perforated support if necessary). The lower face of the test specimen delineates the test volume. The support, if used, sha

46、ll have a minimum open area of50% evenly distributed. The holes in the support shall have a diameter not less than3mm. NOTE 3In some cases it may be necessary to increase the percentage of the open area in order not to restrict the airflow through the test specimen. The flow resistance of such eleme

47、nts (measured with an airflow rate greater than the maximum airflow rate to be used during the specimen test) should be less than1% of the flow resistance measured when testing the specimen. 4.2.2 Device for producing alternating airflow The alternating volumetric airflow rate is produced by a pisto

48、n moving sinusoidally at a frequency of about2Hz. Its r.m.s. value, q V, r.m.s. , in cubic metres per second, is given by The resulting r.m.s. value of the linear airflow velocity, u r.m.s. , in metres per second, is given by It is recommended that the range of u r.m.s.values be between0,5mm/s and4m

49、m/s. The alternating pressure in the specimen holder shall be measured by a laterally mounted condenser microphone connected to an amplifier and meter. The pressure measurement device shall be calibrated using a pistonphone connected to the specimen holder. The specimen holder vessel is closed airtight for the calibration; the specimen holder is also closed airtight for the measurement. The alternating pressure with the pistonphone, p eff , in pascals, is given by where f is the frequenc