1、BSI Standards PublicationBS EN 1793-4:2015Road traffic noise reducingdevices Test method fordetermining the acousticperformancePart 4: Intrinsic characteristics In situvalues of sound diffractionBS EN 1793-4:2015 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN 1
2、793-4:2015.The UK participation in its preparation was entrusted to Technical Committee B/509/6, Fences for the attenuation of noise.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provis
3、ions of a contract. Users are responsible for its correct application. The British Standards Institution 2015.Published by BSI Standards Limited 2015ISBN 978 0 580 86099 7ICS 17.140.30; 93.080.30Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard wa
4、s published under the authority of the Standards Policy and Strategy Committee on 31 March 2015.Amendments/corrigenda issued since publicationDate T e x t a f f e c t e dBS EN 1793-4:2015EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 1793-4 March 2015 ICS 17.140.30; 93.080.30 Supersedes CEN/TS
5、 1793-4:2003English Version Road traffic noise reducing devices - Test method for determining the acoustic performance - Part 4: Intrinsic characteristics - In situ values of sound diffraction Dispositifs de rduction du bruit du trafic routier - Mthode dessai pour la dtermination des performances ac
6、oustiques - Partie 4: Caractristiques intrinsques - Valeurs in-situ de la diffraction acoustique Lrmschutzvorrichtungen an Straen - Prfverfahren zur Bestimmung der akustischen Eigenschaften - Teil 4: Produktspezifische Merkmale - In-situ-Werte der Schallbeugung This European Standard was approved by
7、 CEN on 13 December 2014. 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 stan
8、dards 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 n
9、otified 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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary,
10、 Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC
11、Management Centre: Avenue Marnix 17, B-1000 Brussels 2015 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 1793-4:2015 EBS EN 1793-4:2015Contents Page Foreword 4 Introduction . 5 1 Scope 6 2 Normative references 6 3 Terms, definitio
12、ns and symbols . 7 3.1 Terms and definitions . 7 3.2 Symbols 8 4 Sound diffraction index difference measurements 10 4.1 General principle . 10 4.2 Dimensions and specifications 10 4.2.1 Added devices . 10 4.2.2 Reference walls 10 4.2.3 In situ tests . 11 4.3 Positions of the sound source . 11 4.4 Po
13、sition of the microphone(s) 12 4.5 Free-field measurements 13 4.6 Measured quantity . 17 4.7 Measuring equipment 18 4.7.1 Components of the measuring system . 18 4.7.2 Sound source . 19 4.7.3 Test signal 20 4.8 Data processing . 20 4.8.1 Calibration 20 4.8.2 Sample rate. 20 4.8.3 Background noise .
14、21 4.8.4 Measurement points 21 4.8.5 Adrienne temporal window . 21 4.8.6 Placement of the Adrienne temporal window . 22 4.8.7 Low frequency limit and sample size 23 4.9 Positioning of the measuring equipment 24 4.9.1 Selection of the measurement positions 24 4.9.2 Reflecting objects 24 4.9.3 Safety
15、considerations . 25 4.10 Sound diffraction index difference 25 4.11 Single-number rating of sound diffraction index difference DLDI. 25 4.12 Sample surface and meteorological conditions . 26 4.12.1 Condition of the sample surface 26 4.12.2 Wind 26 4.12.3 Air temperature 26 5 Measurement uncertainty
16、. 26 6 Measuring procedure 26 6.1 General 26 6.2 Test report 27 Annex A (informative) Indoor measurements for product qualification 29 A.1 General 29 A.2 Parasitic reflections . 29 A.3 Reverberation time of the room . 29 Annex B (informative) Measurement uncertainty. 30 EN 1793-4:2015 (E)BS EN 1793-
17、4:2015B.1 General . 30 B.2 Expression for the calculation of sound diffraction index 30 B.3 Contributions to measurement uncertainty 31 B.4 Expanded uncertainty of measurement 32 B.5 Measurement uncertainty based upon reproducibility data . 32 Bibliography 33 EN 1793-4:2015 (E)BS EN 1793-4:2015Forew
18、ord This document (EN 1793-4:2015) has been prepared by Technical Committee CEN/TC 226 “Road equipment”, 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
19、September 2015 and conflicting national standards shall be withdrawn at the latest by September 2015. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such
20、 patent rights. This document supersedes CEN/TS 1793-4:2003. The major changes compared to the previous published version are: the airborne sound insulation characteristics of the reference wall are specified in terms of the minimum values of the Sound Insulation Index, measured according to EN 1793
21、-6, it needs to have; the sound absorbing characteristics of the reference wall are specified in terms of the minimum values of the sound absorption coefficient, measured according to EN ISO 354, it needs to have when lined on the source side with an absorptive flat layer of a single porous material
22、; the sound source positions have been reduced from six to four and are now all obligatory; the microphone positions have been reduced from 12 to 10 and are now all obligatory; a “free-field” impulse response to be measured for each microphone position and therefore a geometrical spreading correctio
23、n factor is no more needed in Formula (1); consideration of the measurement uncertainty has been added (see Clause 5 and Annex B); the summary of the test procedure (Clause 6) has been updated to reflect the changes compared to the previous published version. This document should be read in conjunct
24、ion with: EN 1793-1, Road traffic noise reducing devices Test method for determining the acoustic performance Part 1: Intrinsic characteristics of sound absorption under diffuse sound field conditions EN 1793-3, Road traffic noise reducing devices Test method for determining the acoustic performance
25、 Part 3: Normalized traffic noise spectrum CEN/TS 1793-5, Road traffic noise reducing devices Test method for determining the acoustic performance Part 5: Intrinsic characteristics In situ values of sound reflection and airborne sound insulation. EN 1793-6, Road traffic noise reducing devices Test m
26、ethod for determining the acoustic performance Part 6: Intrinsic characteristics In situ values of airborne sound insulation under direct sound field conditions According to the CEN-CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement t
27、his European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slova
28、kia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. EN 1793-4:2015 (E)BS EN 1793-4:2015Introduction Part of the market of road traffic noise reducing devices is constituted of products to be added on the top of noise reducing devices and intended to contribute to sound attenuat
29、ion acting primarily on the diffracted sound field. These products will be called added devices. This European Standard has been developed to specify a test method for determining the acoustic performance of added devices. The test method can be applied in situ, i.e. where the traffic noise reducing
30、 devices and the added devices are installed. The method can be applied without damaging the traffic noise reducing devices or the added devices. The method can be used to qualify products before the installation along roads as well as to verify the compliance of installed added devices to design sp
31、ecifications. Repeated application of the method can be used to verify the long term performance of added devices. This method could be used to qualify added devices for other applications, e.g. to be installed along railways or nearby industrial sites. In this case, special care needs to be taken i
32、nto account in considering the location of the noise sources and the single-number ratings should be calculated using an appropriate spectrum. No other national or international standard exists about the subject of this European Standard. EN 1793-4:2015 (E)BS EN 1793-4:20151 Scope This European Stan
33、dard describes a test method for determining the intrinsic characteristics of sound diffraction of added devices installed on the top of traffic noise reducing devices. The test method prescribes measurements of the sound pressure level at several reference points near the top edge of a noise reduci
34、ng device with and without the added device installed on its top. The effectiveness of the added device is calculated as the difference between the measured values with and without the added devices, correcting for any change in height (the method described gives the acoustic benefit over a simple b
35、arrier of the same height; however, in practice the added device can raise the height and this could provide additional screening depending on the source and receiver positions). The test method is intended for the following applications: preliminary qualification, outdoors or indoors, of added devi
36、ces to be installed on noise reducing devices; determination of sound diffraction index difference of added devices in actual use; comparison of design specifications with actual performance data after the completion of the construction work; verification of the long term performance of added device
37、s (with a repeated application of the method); interactive design process of new products, including the formulation of installation manuals. The test method can be applied both in situ and on samples purposely built to be tested using the method described here. Results are expressed as a function o
38、f frequency, in one-third octave bands between 100 Hz and 5 kHz. If it is not possible to get valid measurements results over the whole frequency range indicated, the results shall be given in the restricted frequency range and the reasons of the restriction(s) shall be clearly reported. A single-nu
39、mber rating is calculated from frequency data. For indoors measurements see Annex A. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For u
40、ndated references, the latest edition of the referenced document (including any amendments) applies. EN 1793-3, Road traffic noise reducing devices Test method for determining the acoustic performance Part 3: Normalized traffic noise spectrum EN 1793-6, Road traffic noise reducing devices Test metho
41、d for determining the acoustic performance Part 6: Intrinsic characteristics In situ values of airborne sound insulation under direct sound field conditions EN 61672-1, Electroacoustics Sound level meters Part 1: Specifications EN ISO 354, Acoustics Measurement of sound absorption in a reverberation
42、 room (ISO 354) ISO/IEC Guide 98, Guide to the expression of uncertainty in measurement (GUM) EN 1793-4:2015 (E)BS EN 1793-4:20153 Terms, definitions and symbols 3.1 Terms and definitions For the purpose of this document, the following terms and definitions apply. 3.1.1 structural elements those ele
43、ments whose primary function is to support or hold in place acoustic elements 3.1.2 acoustical elements those elements whose primary function is to provide the acoustic performance of the device 3.1.3 noise barrier noise reducing device which obstructs the direct transmission of airborne sound emana
44、ting from road traffic 3.1.4 added device acoustic element added on the top of a noise reducing device and intended to contribute to sound attenuation acting primarily on the diffracted sound field 3.1.5 roadside exposure use of the product as a noise reducing device installed alongside roads 3.1.6
45、sound diffraction index result of a sound diffraction test whose components are described by the formula in 4.6 Note 1 to entry: The symbol for the sound diffraction index includes information on the setup used during the test: DIx,reflrefers to measurements on a reflective reference wall. DIx,absre
46、fers to measurements on an absorptive reference wall. DIx,siturefers to in situ measurements; where x is “0” when the added device is not on the top of the test construction and “ad” when the added device is on the top of the test construction (see 3.2). 3.1.7 sound diffraction index difference diff
47、erence between the results of sound diffraction tests on the same reference wall with and without an added device on the top, described by the formulae in 4.10 3.1.8 test construction construction on which the added device is placed Note 1 to entry: For in situ measurements the test construction is
48、an installed noise reducing device; for qualification tests it is a reference wall (see 4.2). 3.1.9 reference plane of the test construction vertical plane passing through the midpoint of the top edge of the construction (reference wall or installed noise reducing device) on which the added device h
49、as to be placed (see Figure 1, Figure 2, Figure 4, Figure 5 and Figure 8) 3.1.10 reference height of the test construction without the added device, href,0height of the highest point of the test construction in relation to the surrounding ground surface EN 1793-4:2015 (E)BS EN 1793-4:2015Note 1 to entry: This highest point is not necessarily lying in the plane of longitudinal symmetry of the reference test construction, if this symmetry exists (Figure 1). 3.1.11 reference height of the test construction with t
