1、DEUTSCHE NORM Januarv 1999 Recommended practice for the design of low-noise workplaces containing machinery Part 3: Sound propagation and noise prediction in workrooms (ISO/TR 1 1690-3 1997) English version of DIN EN IS0 11 690-3 DIN - EN IS0 11690-2 ICs 13.140; 17.140.20 Descriptors: Noise control,
2、 workplaces, sound distribution. Akustik - Richtlinien fr die Gestaltung Irmarmer maschinenbestckter Arbeitssttten - Teil 3: Schallaus- breitung und -vorausberechnung in Arbeitsrumen (ISO/TR 1 1690-3 : 1997) European Standard EN IS0 11690-3 : 1998 has the status of a DIN Standard. A comma is used as
3、 the decimal marker. National foreword This standard has been published in accordance with a decision taken by CEN/TC 21 1 to adopt, without alteration, International Standard ISO/TR 11 690-3 as a European Standard. The responsible German body involved in its preparation was the Normenausschu Akusti
4、k, Larmminderung und Schwingungstechnik (Acoustics, Noise Control and Vibration Engineering Standards Committee). In connection with this standard, reference is made to DIN EN IS0 11 690-1, DIN EN IS0 11 690-2, DIN IS0 14257*) and VDI 3760. National Annex NA Standards referred to (and not included i
5、n References) DIN EN IS0 11690-1 Recommended practice for the design of low-noise workplaces containing ma- chinery - Part 1 : Noise control strategies (IS0 11 690-1 : 1996) DIN EN IS0 11690-2 Recommended practice for the design of low-noise workplaces containing ma- chinery - Part 2: Noise control
6、measures (IS0 l 1690-2 : 1996) VDI-Richtlinie (VDI Code Measurement of sound propagation and prediction of noise in workrooms of practice) 3760 *) At present at draft stage. EN comprises 38 pages. No pari of this standard may be reproduced without the prior permission of Ref. No. DIN EN IS0 11690-3
7、: 1999-0 V Deutsches Institut fur Normung e. V., Berlin. Luth Verlag GmbH, D-10772 Berlin, has the exclusive right of sale for German Standards (DIN-Normen). English pricegroup 14 Sales No. 1114 07.99 EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN IS0 11690-3 November 1998 ICs 13.140; 17.140.1
8、0 Descriptors: Noise control, workplaces, sound distribution. English version Acoustics Recommended practice for the design of low-noise workplaces containing machinery Part 3: Sound propagation and noise prediction in workrooms (iSO/TR 1 1690-3 : 1997) Acoustique - Pratique recommande pour la conce
9、ption de locaux de travail bruit rduit contenant des machines - Partie 3: Propagation du son et prvision du bruit dans les Akustik - Richtlinien fr die Gestaltung Irmarmer maschinenbestckter Arbeitssttten - Teil 3: Schallaus- breitung und -vorausberechnung in Arbeitsrumen locaux de travail (ISO/TR 1
10、1 690-3 : 1997) (iSO/TR 11 690-3 : 1997) This European Standard was approved by CEN on 1998-01 -09. CEN members are bound to comply with the CENKENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-t
11、o-date lists and bibliographical references concerning such national stand- ards may be obtained on application to the Central Secretariat or to any CEN member. The European Standards exist in three official versions (English, French, German). A version in any other language made by translation unde
12、r 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, the Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy,
13、Luxembourg, the Netherlands, Norway, Portugal, Spain, Sweden, Switzerland, and the United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels O 1998. CEN - All rights of exploitatio
14、n in any form and by any means reserved worldwide for CEN national members. Ref. No. EN IS0 11690-3 : 1998 E Page 2 EN IS0 11 690-3 : 1998 Foreword International Standard ISO/TR 11 690-3 : 1997 Acoustics - Recommended practice for the design of low-noise workplaces contain- which was prepared by ISO
15、/TC 43 Acoustics of the International Organization for Standardization, has been adopted by Technical Committee CEN/TC 21 1 Acoustics, the Secretariat of which is held by DS, as a European Standard. This European Standard shall be given the status of a national standard, either by publication of an
16、identical text or by endorsement, and conflicting national standards withdrawn, by May 1999 at the latest. In accordance with the CENXENELEC Internal Regulations, the national standards organizations of the follow- ing countries are bound to implement this European Standard: Austria, Belgium, the Cz
17、ech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, the Netherlands, Norway, Portugal, Spain, Sweden, Switzerland, and the United Kingdom. ing machinery - Part 3: Sound propagation and noise prediction in workrooms, Warning This document was published as a E
18、uropean Standard to provide a harmonized base for national standards. It is a guidance document, which means that it cannot be used for type approval purposes. The guidance contained in this standard is not intended to be exhaustive, but to highlight important aspects to which attention should be gi
19、ven. Endorsement notice The text of the International Standard ISO/TR 11 690-3 : 1997 was approved by CEN as a European Standard without any modification. Contents Page 1 Scope 4 2 References . 4 3 Definitions 4 4 Basic principies of sound propagation in rooms . 4 5 Noise prediction in workrooms 8 6
20、 Methodology for noise prediction in workrooms 8 7 Further aspects of noise prediction 17 Annexes A Three case studies relating to noise prediction in workrooms 18 6 Prediction of the noise impact of new machines in existing workrooms . 26 C Determination of the sound pressure level at the workstati
21、on of a machine in a workroom . -31 D Evaluation of the acoustical quality of a workroom . .34 E Recommendation for the use of noise prediction methods . 36 F Bibliography .37 Page 3 EN IS0 11 690-3 : 1998 Introduction This Technical Report is intended for use by all parties involved in noise reduct
22、ion in workplaces and design of low-noise workplaces. The objective is: - to make them aware of what is the current technical consensus regarding sound propagation and noise prediction in workrooms, - to aid the interaction between them within a common technical framework, - to promote the understan
23、ding of the desired noise control requirements. This Technical Report provides the connection between the emission of sound sources e.g. machines and the sound pressure level at workstations caused by their operation in a workroom. Therefore, it allows an interchange of information between machine s
24、uppliers, who are responsible for noise emission values, and machine users, who require low noise immission values. A further target is the assessment of the acoustical performance of a workroom. These tasks are connected by the determination of the sound propagation descriptors of a workroom. A met
25、hodology for noise prediction in workrooms is presented and a structure is given for the classification of prediction methods according to the level of detail of input parameters. Page 4 EN IS0 11 690-3 : 1998 1 Scope In this pari of IS0 11 690, sound propagation in a room is considered together wit
26、h the prediction of sound pressure levels and of noise immission at the workplace. Details of the description of the physical phenomena involved in a noise prediction scheme are strongiy dependent on the situation being considered and the way this situation is modelled (input parameters, calculation
27、 techniques). This dependency is surveyed and the methodology for noise prediction is described. Recommendations are provided concerning the use of noise prediction as an aid for noise control in workrooms. Examples of use of noise prediction methods are given in annexes A to E. 2 References Referen
28、ces listed in IS0 11690-1 should also be consulted when using this Technical Report. Definitions given in IS0 11690-1 apply to this Technical Report. 4 Basic principles of sound propagation in rooms 4.1 Sound propagation descriptors A basic element for noise prediction in workrooms is the prediction
29、 of the distribution of sound pressure levels caused by an omnidirectional point source. This distribution is influenced by : - the shape and the volume of the room, - the absorption of the surfaces, - the fittings. Page 5 EN IS0 11 690-3 : 1998 The resulting sound level distribution can be consider
30、ed using a spatial sound distribution curve (see definition 3.4.11 of part 1 and figures 1 and 2 of this Technical Report). The information contained in this curve can be summarized, for a given distance range, by two quantities (see definitions 3.4.12 and 3.4.13 of part 1) : - the rate of spatial d
31、ecay of sound pressure level per distance doubling (DU)! - the excess of sound pressure level with respect to a free field (DU). The spatial sound distribution curve and these two quantities are used to describe the acoustical characteristics of a room. The sound pressure level caused by a given sou
32、rce is indeed smaller if DLf is low and DL2 is high (see 6.3 of part 2). Annex D shows how the acoustical characteristics of a room can be described from spatial sound distribution curves. The spatial sound distribution curve is determined on a free path with no obstacle between the source and the r
33、eceiver. For its measurement, see 8.4 of part 2. NOTES 1 An International Standard specific to the measurement of spatial sound distribution curves in rooms is in preparation (IS0 14257 presently at the stage of drafl). 2 When sound sources (machines) with dimensions too large to be neglected are co
34、nsidered, the sound distribution curve may differ from that of a point source for distances less than the typical dimension of the machine. 4.2 Rooms with diffuse sound fields If diffuse sound field conditions are met (see definitions 3.4.8 and 3.4.9 of part l), at a certain distance from the source
35、, sound pressure levels are nearly constant and independent of receiver position, as shown in figure 1. Page 6 EN IS0 11 690-3 : 1998 1 2 3 45 T L 4 10 rn 50 100 distance - M n hall 15 m x 15 rn x 5 rn hall 30 m x 30 rn x 12 m ._- free field Figure 1 : Examples of spatial sound distribution curves f
36、or an omnidirectional point source and two rooms with different sizes, equal absorption coefficients and diffuse field. The dotted curve is the spatial sound distribution curve under total free field conditions. LP denotes the sound pressure level at a given point when the sound power level of the s
37、ource is 100 dB. The sound pressure level of the diffuse field depends only on the total sound power level of ail sources in the room and on the equivalent absorption area A. In rooms with a diffuse sound field, there is a direct connection between the reverberation time and the expected spatial sou
38、nd distribution curve. It is therefore also possible to qualify such rooms by their reverberation time. In this case, noise prediction is relatively simple. Page 7 EN IS0 11 690-3 : 1998 4.3 Rooms with uniform sound propagation In many workrooms, diffuse sound field conditions cannot be assumed e.g.
39、 because the height of the room is less than one third of the length (flat rooms). In such rooms, even far from the source, the sound field depends on the position being considered and is characterized by a spatial sound distribution curve. In many workrooms, it can be assumed that the absorption an
40、d the fitting density are similar in different parts of the room (this includes a room with an absorbing ceiling and a reflecting floor). In this case, a single spatial sound distribution curve along a free path (not close to walls or fittings) represents the sound propagation and the acoustical qua
41、lity of the room. As an example, figure 2 shows two typical spatial sound distribution curves flat room containing fittings. 90 dB 85 80 75 70 1 2 3 45 10 m 50 in a 100 with fittings, with reflecting ceiling with fittings, with absorbing ceiling -.- free field distance - Figure 2 : Examples of typic
42、al spatial sound distribution curves for the same flat and fitted room, with and without sound absorbing ceiling. The dotted curve is the spatial sound distribution curve under total free field conditions. Lp denotes the sound pressure level at a given point when the sound power level of the source
43、is 100 dB. Page 8 EN IS0 11 690-3 : 1998 It is often useful to split the spatial sound distribution curve into three sections depending on the distance from the source (see 3.4.1 1 of part 1). The first section corresponds to the region near the source. In this region, the sound field is dominated b
44、y the direct field. The rate of spatial decay per distance doubling, DL2, is in most cases approximately 5 dB to 6 dB. Increasing the number of fittings in the vicinity of the source tends to increase the sound pressure level close to the source and to reduce it far from the source. The second secti
45、on of this curve corresponds to a middle region. In this region, DL2 lies in the range 2 dB to 5 dB and DU in the range 2 dB to 10 dB. In the far region (third part), scattering effects of fittings are important. The absorption of the walls, the density and the absorption of fittings have a dominant
46、 influence on the sound propagation far away from the source. Therefore, in this region, DL2 may be greater than 6 dB and DU may be negative. 4.4 Rooms with non uniform sound propagation In some situations, the room shape, absorption and fitting density differ from one part of the room to the other
47、to such an extent that it is not possible to describe the sound propagation in the room with a single spatial sound distribution curve. In such situations, it may be necessary to describe the sound field in a way which takes into account the above factors. Fittings can also be considered individuall
48、y. 5 Noise prediction in workrooms Noise prediction in workrooms (see 9 of part 1) is an aid in making decisions regarding noise control measures. It allows calculation of the sound pressure level at any point and determination of sound propagation descriptors. It is therefore possible to compare th
49、ese values with specified values or limits and to compare various solutions of a noise control programme. Although several noise prediction methods are available, all of them are based on a common procedure. This procedure is summarized in the flow chart shown in figure 3 and is outlined in the next clause. 6 Methodology for noise prediction in workrooms Noise prediction in workrooms should follow five steps described below 6.1 Objectives - Values to be achieved At an early stage of a noise prediction scheme, acoustical descriptors must be chosen and target valu
