1、DEUTSCHE NORM February 1997 DIN Recommended practice for the design of low-noise workplaces containing machinery EN IS0 11690-2 Part 2: Noise control measures (IS0 11 690-2 : 1996) Enalish version of DIN EN IS0 11690-2 ICs 13.140; 17.140.20 Descriptors: Noise control, workplaces, design. Akustik - R
2、ichtlinien fr die Gestaltung Irmarmer maschinenbestckter Arbeitssttten - Teil 2: Lrmminderungs- manahmen (IS0 11690-2 : 1996) European Standard EN IS0 11690-2: 1996 has the status of a DIN Standard. A comma is used as the decimal marker. National foreword This standard has been published in accordan
3、ce with a decision taken by CENTTG 211 to adopt, without alteration, International Standard IS0 11690-2 as a European Standard. The responsible German body involved in its preparation was the Normenausschu Akustik, Lrmminderung und Schwingungstechnik (Acoustics, Noise Control and Vibration Engineeri
4、ng Standards Committee). DIN EN IS0 11690-1 is the DIN Standard corresponding to International Standard IS0 11690-1 referred to in clause 2 of the EN. Standard referred to (and not included in Normative reference and Annex ZA) DIN EN IS0 11690-1 Recommended practice for the design of low-noise workp
5、laces containing machinery - Noise control strategies (IS0 11690-1 :1996) EN comprises 26 pages. O No part of this standard may be reproduced without the prior permission of DIN Deutsches institut fr Normung e.V., Berlin. Beuth Verlag GmbH, Berlin, has the exclusive right of sale for German Standard
6、s (DIN-Normen). Ref. No. DIN EN IS0 11690-2: 1997-02 Sales No. 11 12 10.97 English price group 12 EUROPEAN STAN DAR D NORME EUROPENNE EUROPISCHE NORM EN IS0 11690-2 November 1996 ICs 13.140 Descriptors: Noise control, workplaces, design. English version Acoustics Recommended practice for the design
7、of I o w-n Oise workplaces contai n i ng mach i nery Part 1 : Noise control measures (IS0 11 690-2 : 1996) Acoustique - Pratique recommande pour la conception de lieux de travail bruit rduit contenant des machines - Partie 2: Moyens de rduction du bruit Akustik - Richtlinien fr die Gestaltung Irmarm
8、er maschinenbestckter Arbeitssttten - Teil 2: Lrmminderungs- manahmen (IS0 11690-2:1996) (IS0 11 690-2 : 1996) This European Standard was approved by CEN on 1996-10-16 and is identical to the IS0 Standard as referred to. CEN members are bound to comply with the CENKENELEC Internai Regulations which
9、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. The European Standar
10、ds exist 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 standar
11、ds bodies of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Por- tugal, Spain, Sweden, Switzerland, and the United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung
12、 Central Secretariat: rue de Stassart 36, B-IO50 Brussels O 1996. CEN - All rights of exploitation in any form and by any means reserved worldwide for CEN national members. Ref. No. EN IS0 11690-2 : 1996 E Page 2 EN IS0 11 690-2 1996 Foreword International Standard IS0 11 690-2 : 1996 Acoustics - Re
13、commended practice for the design of low-noise workplaces containing machinery - Noise control measures, which was prepared by ISO/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
14、 DS, as a European Standard. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, and conflicting national standards withdrawn, by May 1997 at the latest. In accordance with the CENKENELEC Internal Regulations, the fol
15、lowing 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 the United Kingdom. Endorsement notice The text of the International Standa
16、rd IS0 11690-2 11996 was approved by CEN as a European Standard without any modi- fication. NOTE: Normative references to international publications are listed in Annex ZA (normative). Contents Scope . . . . . ._. _. . . . . . . . ,. . . . . . . . , . . . . Normative reference ._ ._. ._._. . Definit
17、ions . . . . . Technical aspects of noise control .# . . . . . . , . . Noise control at source . Noise control on the transmission path . Noise control at the work station Verification methods . al 2 110 L 3 ul u7 W ,“ 100 c O U 90 m .- ? 4 80 al b) cl b) Steel working plate. damped by viscous mater
18、ial, 40 mm thick c) Steel working plate, 200 mm thick Figure 6 - Example of sound pressure level when hammering a) Without magnetic mat lDA = 111 dB b) With magnetic mat lpA = 102 dB 125 250 500 1000 4000 Ortave-band frequency. Hz 2000 8000 Figure 7 - Example of sound pressure level when grinding a
19、steel plate 6 Noise control on the transmission path 6.2 Use of noise control devices 6.1 Noise control by means of a proper spatial arrangement of the noise sources An optimized spatial arrangement of machines can provide a substantial noise level reduction at work sta- tions. This is mainly applic
20、able when planning new plants and installations but should also be considered for existing plants. Noise reduction can be obtained by increasing the distance between the noise sources and the work sta- tions (see annex B). Enclosures (see annex C), silencers (see annex D) and screens (see annex E) c
21、an be effective measures for the reduction of the noise emitted from machines, installations, piping systems and openings. An enclosure is a structure completely surrounding the machine or installation. It consists mainly of a sound- insulating shell (metal, wood, concrete, etc.) with an internal so
22、und-absorbing lining. The achievable noise reduction depends on the insulation of airborne sound provided by the shell and on the degree of absorption by the internal surface of the enclosure. In practice, it Page 10 EN IS0 11690-2 : 1996 All rooms with absorbing ceiling, with fittings I 0,3 is limi
23、ted by openings, ineffective seals and by trans- mission of structure-borne sound. This limitation can be minimized by using measures such as silenced openings. 5 to 8 3,5 to 5 The effectiveness of noise control by using enclo- sures, silencers or screens can be measured and as- sessed by the insert
24、ion loss, the transmission loss and the reduction of sound level (see IS0 11690-1:1996, clause 3, for definitions). 6.3 Noise control by use of sound-absorbing materials The relationship between noise emission and noise immission is determined by sound propagation (see IS0 11 690-3). Sound propagati
25、on and therefore the acoustical quality of a room are influenced by the treatment of surfaces (ceiling and walls) by using sound-absorbing materials, which should be selected in relation to the frequency spectrum of the noise. For attenuation of noise at low frequencies, the use of ab- sorptive mate
26、rials is less effective. Noise in rooms consists of direct noise from sources and reflected noise from room boundaries (floors, walls, ceilings, other equipment, fittings, etc.). Absorp- tive surface treatment reduces exclusively the re- flected noise. It is possible to assess the acoustical quality
27、 of a room and therefore the effectiveness of a surface treatment by using the sound propagation quantities, e.g. the rate of spatial decay (DL2) and the excess (DLf) of sound pressure levels. These quantities are derived from the spatial sound distribution curves (see IS0 1 1690-1 for definitions a
28、nd also ISO/TR 1 1690-3). Recommended values of DL2 are given in IS0 11690-1 :I 996, table 3 (see also table 2 of this part of IS0 11690). The assessment can be made from quantities measured (see clause 8) or calculated using noise-prediction methods (see IS0 1 1690-3). The acoustical quality of a r
29、oom is high if DLf is low and DL2 is high. Typical values for average sound ab- sorption coefficient and for sound propagation param- eters DL;! and DLf are given in table 2 for different types of rooms and surface treatments. Generally, industrial noise lies in the frequency range 500 Hz to 2 O00 H
30、z. In such situations, the following reductions in sound pressure level relative to rooms with hard walls and ceiling may be achieved. a) In the near region, the reduction of the A-weighted sound pressure level is in the range 1 dB to 3 dB because surface treatment has very little effect (see IS0 11
31、690-1 for definitions). b) In the middle region, this reduction is usually be- tween 3 dB and 8 dB. c) In the far region, it usually lies between 5 di3 and 12 dB, depending on the room dimensions and the extent of wall treatment and fittings. In order to assess the effectiveness of a surface treatme
32、nt outside the direct field, distinction should be made between rooms with and without diffuse field conditions (see IS0 11690-1 for definitions and also annex F and IS0 11690-3). Typical spatial sound distribution curves in rooms of different shapes and sizes before and after installation of a vari
33、ety of surface treatments are given in figures 8 and 9. The combination of surface treatment and noise barri- ers is normally quite effective and leads to a noise level reduction which is substantially higher than that obtained with only one of these measures (see an- nexes E and F). In addition to
34、the noise reduction which can be measured objectively, there will be an important subjective improvement. More information on surface treatment is given in an- nex F. Table 2 - Typical values for the average sound absorption coefficient (a) and sound propagation descriptors DLf and DL2 in the middle
35、 region Description of rooms I d p 80 i ?O 3 a c 60 u O Ul Sound-absorbing- material 63 250 1000 4000 “A“ 31,s 125 500 2000 8000 Octave-band frequency, Hz b) 100 - 63 250 1000 4000 “A“ 31.5 125 500 2000 8000 Octave-band frequency, Hz 100 m u u O v) c 60 50 63 250 1000 4000 “A“ 31,s 125 500 2000 8000
36、 Octave-band frequency, Hz Figure C.l - Typical noise reduction achieved for different machine and enclosure configurations Page 17 EN IS0 1 1690-2 1996 Annex D (i n f o r m at ive) Silencers Silencers can be categorized as follows, according to the physical action brought into play: a) reactive-typ
37、e silencers (reflection-type and resonator-type), used for instance in internal combustion engines and effective in specific fre- quency ranges; b) throttle silencers, used mainly in blow-out op- erations (high pressure loss); c) dissipative silencers, based on absorbing lin- ings, used mainly for f
38、ans, blowers, compressors and air-conditioning systems. Frequently, a combination of the above is used. All types of silencers have frequency-dependent absorp- tion. It is essential that the choice of a silencer is based on the preliminaiy knowledge of the frequency content of the noise to be attenu
39、ated and on the prac- tical conditions of use, such as - presence of particles, moisture and corrosive constituents in the fluid, - massflow, - pressure, - temperature, - allowable pressure loss, - installation situation. In practice, noise level reduction ranges approximately from 10dB to 20dB. Lar
40、ger values are sometimes achieved. The following International Standards give methods for the measurement of the effectiveness of some types of silencers: IS0 7235, IS0 11691 and IS0 11820. Annex E (informative) Noise barriers and screens in rooms Noise barriers and screens generally consist of shee
41、ts In workrooms without surface treatment, a noise re- of steel, wood, glass or plastic. They should be cov- duction (measured as insertion loss in the 1 kHz ered by sound-absorbing linings on the side facing the octave band) of more than 5 dB can only be achieved source. by barriers and screens of
42、more than half the room height and for distances between the source and the Noise barriers and screens can be used in workplaces receiver of less than three times the room height. where the aim is to prevent direct noise radiation from reaching a point of -immission. Furthermore, they can be used to
43、 separate noisy areas in a room from the rest of the mom, especially in the form of partial-height partitions or lateral enclosures. Separation improves as the remaining connecting surface of the room cross-section decreases and as the absorption on the part of the wall and ceiling surfaces adjacent
44、 to the connecting surface increases. Typically, reductions of A-weighted sound pressure levels of up to 10 dB can be achieved. Noise barriers and screens are most effective when they are combined with wall and ceiling treatments, and the combination should be used when all other measures are not pr
45、acticable. IS0 11821 gives a method for the measurement of the in situ effectiveness of removable screens. IS0 10053 gives a method for the measurement of the effective- ness of office screens. Page 18 EN IS0 11690-2 1996 Room utilization Rooms with equipment such as compressors, fans, etc. Annex F
46、(informative) a 0,05 to O, 1 Acoustical treatment of surfaces Metal-processing hails, machine rooms Wood-processing hails F.l Rooms with a diffuse field 0,l to 0,2 O, 1 to 0,25 In such rooms, and at a certain distance from the source, the sound pressure level is constant (see fig- ure 8). Textile in
47、dustry (e.g. weaving and spinning milis) Mice rooms It is only in this ideal case that the reverberation time, T, can be used to determine the noise level reduction in the diffuse sound field when a certain absorption is added. 0,2 to 0,25 0,15 to 0.2 The noise level reduction yielded by surface tre
48、atment can be easily calculated from the total absorption areas (Al, Ap) or the reverberation times (TI, Tz), where indices 1 and 2 indicate the values before and after treatment, respectively: 10 lg (AZ/A1) or 10 lg (Tl/Tz) The reverberation time (in seconds) in a room under diffuse-field condition
49、s is given by T= 0,163 VIA where v A is the volume of the room, in cubic metres; is the equivalent absorption area of the room (in square metres) given by the partial sur- faces, Si, of the room and the respective ab- sorption coeff icients, ai (see IS0 1 1690-1 ): A = CS,ai Examples of the absorption coefficient are given in table 2 and table F.1. F.2 Rooms with a non-diffuse field In such rooms, parameters describing spatial sound propagation are used to assess the effectiveness of a surface treatment. F.3 Practical hints on surface treatment Som
