1、December 2010 Translation by DIN-Sprachendienst.English price group 12No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).I
2、CS 17.140.30; 93.080.20!$lh“1732969www.din.deDDIN ISO 13472-2Acoustics Measurement of sound absorption properties of road surfaces in situ Part 2: Spot method for reflective surfaces (ISO 13472-2:2010)English translation of DIN ISO 13472-2:2010-12Akustik Messung der Schallabsorptionseigenschaften vo
3、n Straenoberflchen vor Ort Teil 2: Impedanzrohrverfahren fr reflektierende Oberflchen (ISO 13472-2:2010)Englische bersetzung von DIN ISO 13472-2:2010-12Acoustique Mesurage in situ des proprits dabsorption acoustique des revtements de chausses Partie 2: Mthode ponctuelle pour les surfaces rflchissant
4、es (ISO 13472-2:2010)Traduction anglaise de DIN ISO 13472-2:2010-12www.beuth.deDocument comprises 25 pageIn case of doubt, the German-language original shall be considered authoritative.s12.10 DIN ISO 13472-2:2010-12 2 A comma is used as the decimal marker. Contents Page National foreword .3 Nationa
5、l Annex NA (informative) Bibliography.4 Introduction .5 1 Scope 6 2 Normative references 6 3 Terms and definitions7 4 Principle7 5 Test equipment 9 5.1 Components of the test system .9 5.2 Sound source .9 5.3 Test signal 9 5.4 Impedance tube9 5.4.1 Tube diameter 9 5.4.2 Tube length and microphone po
6、sitions 10 5.5 Microphones.11 5.6 In-situ test fixture between impedance tube and test surface 11 5.7 Signal-processing system 11 5.8 Thermometer and pressure measurement11 6 Measurement and analysis procedure.11 6.1 Stabilizing the system .11 6.2 Calibration of the system12 6.3 Reference measuremen
7、t .12 6.4 Background noise measurement .12 6.5 Measurement of a road surface12 6.6 Data analysis 13 7 Positioning of the equipment .13 7.1 Location of the measurement positions13 7.1.1 Test surfaces such as those meeting ISO 10844 requirements13 7.1.2 Regular roads.13 7.2 Condition of the road surfa
8、ce.13 7.3 Temperature .13 8 Measurement and analysis procedure.13 9 Measurement uncertainty .14 10 Test report 16 Annex A (normative) Correction on base of reference measurement .17 Annex B (informative) Measurement uncertainty.18 B.1 General18 B.2 Expression for the calculation of the absorption co
9、efficient18 B.3 Sources of uncertainty19 B.4 Expanded uncertainty of measurement.20 Annex C (informative) Sketch of in-situ test fixture.21 Annex D (informative) Example of a test report .23 Bibliography 25 National foreword This standard has been prepared by Technical Committee ISO/TC 43 “Acoustics
10、”, Subcommittee SC 1 “Noise”, Working Group WG 38 “Procedure for measuring sound absorption properties of road surfaces In-situ method”. The responsible German body involved in its preparation was the Normenausschuss Akustik, Lrmminderung und Schwingungstechnik im DIN und VDI (Acoustics, Noise Contr
11、ol and Vibration Engineering Standards Committee in DIN and VDI), Working Committee NA 001-01-05 AA Geruschemissionsmessungen an Fahrzeugen einschlielich Messungen im Fahrgastraum und am Arbeitsplatz, Subcommittee NA 001-01-05-03 UA Straenfahrzeuge Kenngren. DIN ISO 13472 consists of the following p
12、arts, under the general title Acoustics Measurement of sound absorption properties of road surfaces in situ: Part 1: Extended surface method Part 2: Spot method for reflective surfaces The DIN Standards corresponding to the International Standards referred to in this document are as follows: ISO 354
13、 DIN EN ISO 354 ISO 362 (all parts) DIN ISO 362 (all parts) ISO 10534-1 DIN EN ISO 10534-1 ISO 10534-2 DIN EN ISO 10534-2 ISO 10844 DIN ISO 10844N1)ISO 13472-1 DIN ISO 13472-1 IEC 61260 DIN EN 61260 IEC 61672 (all parts) DIN EN 61672 (all parts) ISO/IEC Guide 98-3 DIN V ENV 13005 These German Standa
14、rds are given in National Annex NA. N1) National footnote: Under revision 3 DIN ISO 13472-2:2010-12 National Annex NA (informative) Bibliography DIN V ENV 13005, Guide to the expression of uncertainty in measurement DIN EN 61260, Electroacoustics Octave-band and fractional-octave-band filters DIN EN
15、 61672 (all parts), Electroacoustics Sound level meters DIN EN ISO 354, Acoustics Measurement of sound absorption in a reverberation room DIN EN ISO 10534-1, Acoustics Determination of sound absorption coefficient and impedance in impedances tubes Part 1: Method using standing wave ratio DIN EN ISO
16、10534-2, Acoustics Determination of sound absorption coefficient and impedance in impedance tubes Part 2: Transfer-function method DIN ISO 362 (all parts), Measurement of noise emitted by accelerating road vehicles Engineering method DIN ISO 10844, Acoustics Specifications of test tracks for the pur
17、pose of measuring noise emitted by road vehicles DIN ISO 13472-1, Acoustics Measurement of sound absorption properties of road surfaces in situ Part 1: Extended surface method 4 DIN ISO 13472-2:2010-12 Introduction This part of ISO 13472 specifies a test method for measuring in situ the sound absorp
18、tion coefficient of road surfaces as a function of frequency under normal incidence. This method enables evaluation of the sound absorption characteristics of a road surface without damaging the surface. It is intended to be used to qualify the absorption characteristics of road surfaces used for ve
19、hicle and tyre testing. It may also be used during road construction, road maintenance, and other traffic noise studies. However, the field of application is limited to low absorption surfaces. The method specified in this part of ISO 13472 is based on propagation of the test signal from the source
20、to the road surface and back to the receiver through an impedance tube. The tube covers an area of approximately 0,008 m2and a frequency range, in one-third-octave bands, from 250 Hz to 1 600 Hz. It uses the test procedure and signal processing specified in ISO 10534-2, but because of the defined fr
21、equency range of application, the dimensions of the system are not adjustable, but fixed. This method is primarily intended for smooth low absorption surfaces, such as those in accordance with ISO 10844. The method is not reliable if the measured sound absorption coefficient exceeds 0,15. Surfaces w
22、ith values above 0,10 are not considered to be reflective. This method is complementary to the extended surface method (ISO 13472-15) that covers an area of approximately 3 m2and a frequency range, in one-third-octave bands, from 250 Hz to 4 000 Hz. Both methods should give similar results in the fr
23、equency range from 315 Hz to 1 600 Hz, but their fields of application and therefore their accuracy differ strongly. The method described in ISO 13472-15has limited accuracy at small sound absorption values and is therefore unsuitable for checking compliance of surfaces with the requirements of such
24、 documents as ISO 10844, while the method specified here fails at higher sound absorption values. Within their ranges, the methods are also applicable to acoustic materials other than road surfaces. The measurement results of this method are comparable to the results of the impedance tube method, pe
25、rformed on bore cores taken from the surface in accordance with documents such as ISO 10534-14, ISO 10534-2 and ASTM E10507. The measurement results obtained with this method are in general not comparable to the results of the reverberation room method (ISO 3541), because the method described in thi
26、s part of ISO 13472 uses a plane progressive wave at perpendicular incidence, while the reverberation room method uses a diffuse sound field. Acoustics Measurement of sound absorption properties of road surfaces Part 2: Spot method for reflective surfaces 5 DIN ISO 13472-2:2010-12 in situ1 Scope Thi
27、s part of ISO 13472 specifies a test method for measuring in situ the sound absorption coefficient of road surfaces for the one-third-octave-band frequencies ranging from 250 Hz to 1 600 Hz under normal incidence conditions. For special purposes, the frequency range can be changed by modifying the d
28、imensions of the system. The test method is intended for: a) determination of the sound absorption coefficient of semi-dense to dense road surfaces (and, if of interest, also the complex acoustical impedance); b) determination of the sound absorption properties of test tracks in accordance with stan
29、dards such as ISO 10844 and test surfaces defined in national and international type approval regulations for road vehicles and vehicle tyres; c) verification of the compliance of the sound absorption coefficient of a road surface with design specifications or other requirements. 2 Normative referen
30、ces The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 10534-2:1998, Acoustics Determination of
31、sound absorption coefficient and impedance in impedance tubes Part 2: Transfer-function method ISO 10844, Acoustics Specification of test tracks for measuring noise emitted by road vehicles and their tyres ISO/IEC Guide 98-3:2008, Uncertainty of measurement Part 3: Guide to the expression of uncerta
32、inty in measurement (GUM:1995) IEC 61260, Electroacoustics Octave-band and fractional-octave-band filters DIN ISO 13472-2:2010-12 6 3 Terms and definitions For the purposes of this document, the following definitions apply. 3.1 frequency range frequency interval in which measurements are valid speci
33、fied in one-third-octave bands in accordance with IEC 61260 NOTE The frequency range is specified in one-third-octave bands. This means that its lower limit is the lower limit of the lowest one-third-octave band specified and its upper limit is the upper limit of the highest one-third-octave band sp
34、ecified. The frequency range specified in one-third-octave bands of 250 Hz to 1 600 Hz centre frequency implies a frequency range specified in narrow bands of 220 Hz to 1 800 Hz. 3.2 sound absorption coefficient at normal incidence ratio of sound power entering the surface of the test object (withou
35、t return) to the incident sound power for a plane wave at normal incidence ISO 10534-2:1998, 2.1 3.3 sound pressure reflection factor at normal incidence r complex ratio of the pressure of the reflected wave to the pressure of the incident wave at the surface of the test object for a plane wave at n
36、ormal incidence 3.4 plane of reference for the road surface hypothetical plane defined by the underside of the sealing device at which the sound pressure reflection factor is calculated 3.5 signal-to-noise ratio level difference, in decibels, between the level of the useful signal and the level of t
37、he background noise 3.6 normal surface impedance Z ratio of the complex sound pressure to the normal component of the complex sound particle velocity at an individual frequency in the reference plane NOTE 1 Adapted from ISO 10534-2:1998, 2.4. NOTE 2 Although not used in specifications of road surfac
38、es, calculating propagation over such a surface requires a complex acoustic impedance. 4 Principle The two microphone impedance tube method (see ISO 10534-2 or ASTM E10507) is adapted to a portable apparatus that enables the normal incidence sound absorption coefficient of plane surfaces to be rapid
39、ly measured over a broad frequency range without distortion of the surface. The procedure enables a single skilled operator to perform such measurements. There is no need for a calibration for microphones as required in typical acoustic measurements, but it does require a specific verification of th
40、e two microphone apparatus for amplitude and phase relationship between microphones at the time of the measurement and a determination of the internal energy loss of the system based on measurements on a totally reflecting plane. DIN ISO 13472-2:2010-12 7 The apparatus is a standard impedance tube u
41、tilizing the two microphone arrangement. A sound signal from a loudspeaker located at one end propagates through the tube. The open end of the tube is placed on the surface to be measured. The complex acoustic transfer function of the two microphone signals is determined and used to compute the norm
42、al incidence sound absorption coefficient and related quantities. The absorption coefficient covers the one-third-octave-band frequency range from 250 Hz to 1 600 Hz. Figure 1 illustrates the system set-up. Key 1 loudspeaker 2 vibration isolation 3 microphones 4 in-situ test fixture 5 sound source a
43、nd amplifier 6 frequency analyser 7 surface under test Figure 1 Configuration of the measuring device and related equipment DIN ISO 13472-2:2010-12 8 The signal processing is described in ISO 10534-2 and ASTM E10507and consists basically of the measurement of the complex transfer function between th
44、e two microphones in the presence of the sample under test. This is then processed to obtain the complex pressure reflection factor from which the acoustic absorption can be calculated. The procedure described in ISO 10534-2 and ASTM E10507includes the calibration of amplitude and phase properties o
45、f the two microphones. In this method, the test sample holder specified in ISO 10534-2 is replaced by an in-situ test fixture that enables an airtight connection between the inside of the test tube and the surface of the road under test. The test tube and the fixture can be either integrated into a
46、single piece or connected by some kind of fixing device and an airtight seal such as a rubber O-ring. On the underside of the in-situ test fixture, a ring of deformable material forms an airtight seal with the surface texture of the road surface on one hand and with the fixture on the other. Sealing
47、 is improved with a small groove made in the fixture (see Figures C.1 and C.2). The sound absorption coefficient is determined in accordance with the procedure specified in ISO 10534-2. 5 Test equipment 5.1 Components of the test system The test equipment comprises a signal generator, a sound source
48、, a tube, two microphones mounted flush with the inside wall of the tube at the specified positions, an in-situ test fixture device to maintain an airtight fit to the surface, and a signal-processing unit capable of doing complex Fourier transforms in two channels simultaneously. Any measurement system that provides the characteristics and meets the criteria specified in ISO 10534-2 is acceptable. 5.2 Sound source The sound source shall meet the requirements defin
