Li ce ns ed C op y le ev in ce nt po w le ev in ce nt po w , M ar ch 1 9, 2 00 2, U nc on tr ol le d C op y, ( c) B S I BRITISH STANDARD BS EN 29053 1993 ISO 9053 1991 Acoustics — Materials for acoust[.]
Licensed Copy: leevincentpow leevincentpow, March 19, 2002, Uncontrolled Copy, (c) BSI British Standard A single copy of this British Standard is licensed to leevincentpow leevincentpow on March 19, 2002 This is an uncontrolled copy Ensure use of the most current version of this document by searching British Standards Online at bsonline.techindex.co.uk BRITISH STANDARD Licensed Copy: leevincentpow leevincentpow, March 19, 2002, Uncontrolled Copy, (c) BSI Acoustics — Materials for acoustical applications — Determination of airflow resistance The European Standard EN 29053:1993 has the status of a British Standard UDC 699.844-405.8:534.833:620.1:533.6.011.3 BS EN 29053:1993 ISO 9053:1991 BS EN 29053:1993 Cooperating organizations Licensed Copy: leevincentpow leevincentpow, March 19, 2002, Uncontrolled Copy, (c) BSI The European Committee for Standardization (CEN), under whose supervision this European Standard was prepared, comprises the national standards organizations of the following countries: Austria Belgium Denmark Finland France Germany Greece Iceland Ireland Italy Luxembourg Netherlands Norway Portugal Spain Sweden Switzerland United Kingdom This British Standard, having been prepared under the direction of the Environment and Pollution Standards Policy Committee, was published under the authority of the Standards Board and comes into effect on 15 May 1993 © BSI 12-1999 The following BSI references relate to the work on this standard: Committee reference EPC/1 Draft for comment 88/56272 DC ISBN 580 21966 Oesterreichisches Normungsinstitut Institut belge de normalisation Dansk Standardiseringsraad Suomen Standardisoimisliito, r.y Association franỗaise de normalisation Deutsches Institut für Normung e.V Hellenic Organization for Standardization Technological Institute of Iceland National Standards Authority of Ireland Ente Nazionale Italiano di Unificazione Inspection du Travail et des Mines Nederlands Normalisatie-instituut Norges Standardiseringsforbund Instituto Portugs da Qualidade Asociación Espola de Normalización y Certificación Standardiseringskommissionen i Sverige Association suisse de normalisation British Standards Institution Amendments issued since publication Amd No Date Comments BS EN 29053:1993 Contents Licensed Copy: leevincentpow leevincentpow, March 19, 2002, Uncontrolled Copy, (c) BSI Page Cooperating organizations Inside front cover National foreword ii Foreword Scope Definitions 3 Principle Equipment Test specimens Test procedure Precision Test report Annex A (informative) Bibliography 10 National annex NA (informative) Committees responsible Inside back cover Figure — Direct airflow method (method A) — Basic principle Figure — Alternating airflow method (method B) — Basic principle Figure — Measurement equipment, with cylindrical section, for direct airflow method (method A) Figure — Measurement cell with specimen holder for measuring fibre materials of loose and wadding structure (method B) Figure — Measurement cell with holder for cylindrical specimen (method B) © BSI 12-1999 i BS EN 29053:1993 National foreword This British Standard has been prepared under the direction of the Environment and Pollution Standards Policy Committee It is the English language version of EN 29053:1993 Acoustics — Materials for acoustical applications — Determination of airflow resistance, published by the European Committee for Standardization (CEN) It is identical with ISO 9053:1991, published by the International Organization for Standardization (ISO) The airflow resistance of porous materials indicates, in an indirect 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 British Standard is, therefore, useful for two purposes: a) relating some of the acoustical 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 Licensed Copy: leevincentpow leevincentpow, March 19, 2002, Uncontrolled Copy, (c) BSI 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, the EN title page, pages to 10, an inside back cover and a back cover This standard has been updated (see copyright date) and may have had amendments incorporated This will be indicated in the amendment table on the inside front cover ii © BSI 12-1999 EUROPEAN STANDARD EN 29053 NORME EUROPÉENNE March 1993 EUROPÄISCHE NORM UDC 699.844-405.8:534.833:620.1:533.6.011.3 Descriptors: Acoustics, acoustic insulation, insulating materials acoustic, porous materials, gas permeability tests, air flow English version Acoustics — Materials for acoustical applications — Determination of airflow resistance Licensed Copy: leevincentpow leevincentpow, March 19, 2002, Uncontrolled Copy, (c) BSI (ISO 9053:1991) Acoustique — Matériaux pour applications acoustiques — Détermination de la résistance l’écoulement de l’air (ISO 9053:1991) Akustik — Materialien für akustische Anwendungen — Bestimmung des Strömungswiderstandes (ISO 9053:1991) This European Standard was approved by CEN 1993-02-12 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 national 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 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, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom CEN European Committee for Standardization Comité Européen de Normalisation Europäisches Komitee für Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels © 1993 Copyright reserved to CEN members Ref No EN 29053:1993 E EN 29053:1993 Licensed Copy: leevincentpow leevincentpow, March 19, 2002, Uncontrolled Copy, (c) BSI Foreword Following the positive result of the primary questionnaire, CEN Technical Board decided to submit ISO 9053:1991 Acoustics — Materials for acoustical applications — Determination of airflow resistance to the formal vote The result 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 September 1993, and conflicting national standards shall be withdrawn at the latest by September 1993 In accordance with the CEN/CENELEC 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 © BSI 12-1999 EN 29053:1993 Scope 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 Details of publications relating to flow behaviour under both laminar and turbulent conditions are given in Annex A Licensed Copy: leevincentpow leevincentpow, March 19, 2002, Uncontrolled Copy, (c) BSI Definitions 2.4 linear airflow velocity, u a quantity defined by q u = -vA where qv A is the volumetric airflow rate, in cubic metres per second, passing through the test specimen; is the cross-sectional area, in square metres, of the test specimen For the purposes of this International Standard, the following definitions apply it is expressed in metres per second 2.1 airflow resistance, R Principle a quantity defined by 3.1 Direct airflow method (method A) %p R = qv where %p qv is the air pressure difference, in pascals, across the test specimen with respect to the atmosphere; is the volumetric airflow rate, in cubic metres per second, passing through the test specimen it is expressed in pascal seconds per cubic metre 2.2 specific airflow resistance, Rs a quantity defined by Rs = RA where R A is the airflow resistance, in pascal seconds per cubic metre, of the test specimen; is the cross-sectional area, in square metres, of the test specimen perpendicular to the direction of flow 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 R r = s d where Rs d is the specific airflow resistance, in pascal seconds per metre, of the test specimen; is the thickness, in metres, of the test specimen in the direction of flow 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 (see Figure 1) 3.2 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) Equipment 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) 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 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 measurement cell is shown in Figure If it is circular in cross-section, the internal diameter shall be greater than 95 mm it is expressed in pascal seconds per square metre © BSI 12-1999 Licensed Copy: leevincentpow leevincentpow, March 19, 2002, Uncontrolled Copy, (c) BSI EN 29053:1993 Figure — Direct airflow method (method A) — Basic principle Figure — Alternating airflow method (method B) — Basic principle © BSI 12-1999 Licensed Copy: leevincentpow leevincentpow, March 19, 2002, Uncontrolled Copy, (c) BSI EN 29053:1993 Figure — Measurement equipment, with cylindrical section, for direct airflow method (method A) For the rectangular parallelepiped shape, the preferred cross-section is a square In any case, all sides shall measure at least 90 mm 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 least 100 mm greater than the thickness of the test specimen The test specimen shall rest inside the measurement 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 of 50 %, evenly distributed The holes in the support shall have a diameter not less than mm NOTE In 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 tapping points for the measurement of pressure and airflow shall be leak-free and arranged below the level of the perforated support © BSI 12-1999 4.1.2 Device for producing airflow It is recommended 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 not contaminate the air Whatever airflow source is used, the installation shall permit fine control of the flow and shall ensure 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 permit airflow velocities down to 0,5 × 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 specimen EN 29053:1993 The arrangement used shall permit measurement of the airflow to an accuracy of ± % of the indicated value 4.1.4 Device for measuring differential pressure The equipment used for measuring differential pressures shall permit measurements of pressures as low as 0,1 Pa The arrangement used shall permit measurement of the differential pressure to an accuracy of ± % of the indicated value Licensed Copy: leevincentpow leevincentpow, March 19, 2002, Uncontrolled Copy, (c) BSI 4.2 Equipment for method B The equipment shall consist of a) a measurement cell into which 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 Two examples of suitable equipment with different specimen holders are shown in Figure and Figure 4.2.1 Measurement cell The measurement cell is composed of two parts: a) the specimen holder; b) the test volume (see Figure and Figure 5) Both parts shall be in the shape of a circular cylinder, as shown in Figure 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 than 95 mm For rectangular specimen holders, the preferred cross-section is a square In any case, all sides shall measure at least 90 mm 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, shall have a minimum open area of 50 % evenly distributed The holes in the support shall have a diameter not less than mm NOTE In 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 elements (measured with an airflow rate greater than the maximum airflow rate to be used during the specimen test) should be less than % 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 piston moving sinusoidally at a frequency of about Hz Its r.m.s value, qV, r.m.s., in cubic metres per second, is given by Ï q V, r.m.s = - fhA p where f h Ap The resulting r.m.s value of the linear airflow velocity, ur.m.s., in metres per second, is given by q V, r.m.s u r.m.s = A where qV, r.m.s is the r.m.s value of the alternating volumetric airflow rate, in cubic metres per second; A is the area, in square metres, of the test specimen It is recommended that the range of ur.m.s values be between 0,5 mm/s and mm/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, peff, in pascals, is given by p V pk p eff = 1,4 0- ⋅ V where p0 Vpk V is the frequency, in hertz, of the piston; is the stroke (peak to peak displacement), in metres, of the piston; is the cross-sectional area, in square metres, of the piston cylinder is the atmospheric pressure, in pascals; is the product of the amplitude and piston cross-sectional area of the calibration pistonphone, in cubic metres; is the volume of the test vessel, in cubic metres © BSI 12-1999 Licensed Copy: leevincentpow leevincentpow, March 19, 2002, Uncontrolled Copy, (c) BSI EN 29053:1993 Figure — Measurement cell with specimen holder for measuring fibre materials of loose and wadding structure (method B) © BSI 12-1999 Licensed Copy: leevincentpow leevincentpow, March 19, 2002, Uncontrolled Copy, (c) BSI EN 29053:1993 Figure — Measurement cell with holder for cylindrical specimen (method B) The measuring device can thus be calibrated absolutely in pressure units With unchanged amplitude of the measuring piston, the scale is able to indicate the specific flow resistance directly The piston of the calibrating pistonphone shall have a diameter of approximately 10 mm and a stroke of approximately mm NOTE Intercomparison measurements of a specimen with known specific flow resistance have shown that the pressure in the test vessel varies nearly adiabatically with the piston operating at Hz 4.3 Device for measuring specimen thickness The specimen holder shall be equipped with a micrometer or other indicator allowing the measurement of specimen thickness to an accuracy of ± 2,5 % of the indicated value Test specimens 5.1 Shape The test specimen may be circular or rectangular, depending on the type of measurement cell available 5.2 Dimensions 5.2.1 Lateral dimensions When testing soft, compressible materials, such as fibrous insulations or flexible foams, care shall be taken in the preparation of the specimens to reduce the possibility of leaks along the edges In these cases, test specimens shall be prepared with lateral dimensions slightly larger than those of the measurement cell Specimens of rigid materials shall have the same dimensions as the measurement cell NOTE Care should be taken to avoid distortion of the test specimen 5.2.2 Thickness The thickness of the test specimen shall be chosen to obtain pressure drops measurable under optimum conditions and to suit the usable depth of the measurement cell If the test specimens available are not sufficiently thick to produce a suitable pressure drop, test specimens — but not more than five — chosen in the same way, may be superimposed 5.3 Number of test specimens At least three samples shall be taken, from each of which three test specimens shall be cut © BSI 12-1999 Licensed Copy: leevincentpow leevincentpow, March 19, 2002, Uncontrolled Copy, (c) BSI EN 29053:1993 Test procedure Precision 6.1 Place the test specimen, prepared as described in clause 5, in the measurement cell 6.2 Ensure that the edges are properly sealed Petroleum jelly may be used to seal the edges of rigid specimens 6.3 Bring the device for measuring the thickness of the test specimens into contact with the upper surface of the test specimens, compressing it lightly if necessary 6.4 Note the thickness and use this measurement to determine the free or the compressed volume and from this derive the free or the compressed density of the test specimen when in position 6.5 Since the specific airflow resistance of many sound-absorbing materials has been found to increase with the linear airflow velocity in a certain range, it should be measured at the smallest possible linear airflow velocity A linear airflow velocity, u, of 0,5 × 10–3 m/s is recommended as the lower limit This value of particle velocity would correspond to a sound pressure of 0,2 Pa (80 dB reference 20 4Pa) In the case of the procedure using direct airflow (method A), the pressure drop %p shall be measured either directly at u = 0,5 × 10–3 m/s or stepwise down to the lower limit of linear airflow velocity The specific airflow resistance shall be calculated in accordance with 2.2 In the case of incremental reduction of airflow, plot for each specimen a graph of specific airflow resistance versus linear airflow velocity From this, the specific airflow resistance for u = 0,5 × 10–3 m/s shall be determined by graphical averaging or, if necessary, by extrapolation to this value In the case of a procedure using alternating airflow (method B), the specific airflow resistance can usually be determined at a r.m.s velocity, u, of 0,5 × 10–3 m/s Otherwise, the step-by-step procedure as described in the case of method A shall be used Interlaboratory precision experiments are planned © BSI 12-1999 Test report The test report shall include the following information in addition to the results calculated for the test specimens as described in 6.5 and their mean and other statistical parameters (standard deviation, etc.), if they are demanded by the product specification: a) a reference to this International Standard; b) the material of the product, and its apparent density, including the appropriate test standard used; c) the method used and its lower limit for determining the airflow resistance; d) the test conditions used, particularly the shape and dimensions of the measurement cell; e) the method of preparation of the test specimen; f) the number of test specimens and their lateral dimensions; g) if necessary, the orientation of the axis of the test specimens with respect to the principal axes of symmetry; h) the presence and nature of any skin; i) the thickness and density of the material as tested; j) any deviation from the procedures specified in this International Standard which may have influenced the results EN 29053:1993 Licensed Copy: leevincentpow leevincentpow, March 19, 2002, Uncontrolled Copy, (c) BSI Annex A (informative) Bibliography [1] ISO 4638:1984, Polymeric materials, cellular flexible — Determination of air flow permeability [2] CREMER, L., Die wissenschaftlichen Grundlagen der Raumakustik (The scientific fundamental principles of room acoustics), vol 3, Leipzig: S Hirzel Verlag, 1950 [3] KRAAK, W., Der dynamische Strömungsstandwert kreisförmiger kurzer Kanäle Hochfrequenztechnik und Elektroakustik, 65 (10), 1956: p 46 [4] REICHARDT, W., Grundlagen der Elektroakustik, 2nd ed., Leipzig: Akademische Verlagsgesellschaft Geest & Portig, 1954 [5] WEBER, K., Apparatur zur Messung kleiner Strömungsstandwerte, Diplomarbeit am Institut für Elektro- und Bauakustik der Technischen Hochschule, Dresden, 1957 [6] JAMES, E.A.J., Gas dynamics, Boston: Allyn and Bacon, 1969 [7] ZWIKKER, C and KOSTEN, C.W., Sound absorbing materials, Amsterdam: Elsevier, 1949 [8] BROWN, R.L and BOLT, R.H., The measurement of flow resistance of porous acoustic materials J Acoust Soc Am., 13 (4), 1942: pp 337–344 10 © BSI 12-1999 BS EN 29053:1993 National annex NA (informative) Committees responsible Licensed Copy: leevincentpow leevincentpow, March 19, 2002, Uncontrolled Copy, (c) BSI The United Kingdom participation in the preparation of this European Standard was entrusted by the Environment and Pollution Standards Policy Committee (EPC/-) to Technical Committee EPC/1, upon which the following bodies were represented: Association of Consulting Engineers British Broadcasting Corporation British Occupational Hygiene Society British Telecommunications plc Department of Health Department of the Environment (Building Research Establishment) Department of Trade and Industry (Air Division) Department of Trade and Industry (National Physical Laboratory) Engineering Equipment and Materials Users’ Association Health and Safety Executive Incorporated Association of Architects and Surveyors Institute of Acoustics Institute of Occupational Hygienists Institute of Physics Institute of Sound and Vibration Research Institution of Electrical Engineers Royal Institute of British Architects Society of Environmental Engineers The following bodies were also represented in the drafting of the standard, through subcommittees and panels: Aggregate Concrete Block Association Association of Building Component Manufacturers Association of Manufacturers of Domestic Unvented Supply Systems Equipment (MODUSSE) Autoclaved Aerated Concrete Products Association Brick Development Association British Bathroom Council British Ceramic Research Ltd British Precast Concrete Federation Ltd Calcium Silicate Brick Association Ltd Concrete Block Association Concrete Society Gypsum Products Development Association Heriott-Watt University Hevac Association Suspended Ceilings Association © BSI 12-1999 BS EN 29053:1993 ISO 9053:1991 BSI — British 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