1、BRITISH STANDARD BS EN ISO 9614-2:1997 Acoustics Determination of sound power levels of noise sources using sound intensity Part 2: Measurement by scanning The European Standard EN ISO 9614-2:1996 has the status of a British Standard ICS 17.140.01BSENISO9614-2:1997 This British Standard, having been
2、 prepared under the directionof the Health and Environment Sector Board, was published under the authority of the Standards Board and comes into effect on 15April1997 BSI 08-1999 The following BSI references relate to the work on this standard: Committee reference EH/1 Draft for comment 94/502144 DC
3、 ISBN 0 580 26658 3 Committees responsible for this British Standard The preparation of this British Standard was entrusted to Technical Committee EH/1, Acoustics, upon which the following bodies were represented: Association of Consulting Engineers British Broadcasting Corporation British Occupatio
4、nal Hygiene Society British Telecommunications plc Department of the Environment (Building Research Establishment) Department of Health Health and Safety Executive Institute of Acoustics Institute of Occupational Hygienists Institute of Sound and Vibration Research Institution of Electrical Engineer
5、s National Physical Laboratory 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: Advanced Manufacturing Technology Research Institute Agricultural Engineers Associatio
6、n British Cement Association British Compressed Air Society British Industrial Truck Association British Iron and Steel Producers Association Construction Industry Research and Information Association Engineering Industries Association Fan Manufacturers Association Federation of the Electronics Indu
7、stry Federation of Manufacturers of Construction Equipment and Cranes Federation of Piling Specialists Hevac Association Institution of Engineering Designers Institution of Mechanical Engineers National Engineering Laboratory National Specialist Contractors Council Rotating Electrical Machines Assoc
8、iation University of Liverpool University of Manchester Amendments issued since publication Amd. No. Date of issue CommentsBSENISO9614-2:1997 BSI 08-1999 i Contents Page Committees responsible Inside front cover National foreword ii Foreword 2 Foreword ii Text of ISO 9614-2 1 List of references Insi
9、de back coverBSENISO9614-2:1997 ii BSI 08-1999 National foreword This British Standard has been prepared by Technical Committee EH/1 and is the English language version of EN ISO9614-2:1996 Acoustics Determination of sound power levels of noise sources using sound intensity Part2:Measurement by scan
10、ning, published by the European Committee for Standardization (CEN), which is identical with ISO9614-2:1996 published by the International Organization for Standardization (ISO). A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are
11、 responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Cross-reference Publication referred to Corresponding British Standard IEC 942:1988 BS 7189:1989 Specification for sound calibrators Summary of pages This documen
12、t comprises a front cover, an inside front cover, pages i and ii, theEN ISO title page, page 2, the ISO title page, page ii, pages 1 to 18, aninsideback 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
13、 amendment table on the inside front cover.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO9614-2 August1996 ICS17.140.00 Descriptors: See ISO document English version Acoustics Determination of sound power levels of noise sources using sound intensity Part2: Measurement by scanning (ISO9614
14、-2:1996) Acoustique Dtermination par intensimtrie des niveaux de puissance acoustique mis par les sources de bruit Partie2: Mesurage par balayage (ISO9614-2:1996) Akustik Bestimmung der Schalleistungspegel von Geruschquellen durch Schallintensittsmessung Teil2:Messig mit kontinuierlicher Abtastung (
15、ISO9614-2:1996) This European Standard was approved by CEN on1996-05-19. 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 bibliogra
16、phical references concerning such national standards 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 under the responsibility of a CE
17、N 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
18、, Sweden, Switzerland and UnitedKingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1996 Copyright reserved to CEN members Ref. No. EN ISO9614-2:1996 EENISO9614-2:1996 BSI 08-1999 2
19、 Foreword The text of the International Standard ISO9614-2:1996 has been prepared by Technical Committee ISO/TC43 “Acoustics” in collaboration with Technical Committee CEN/TC211 “Acoustics”, the secretariat of which is held by DS. This European Standard shall be given the status of a national standa
20、rd, either by publication of an identical text or by endorsement, at the latest by February1997, and conflicting national standards shall be withdrawn at the latest by February1997. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are
21、 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 UnitedKingdom. Endorsement notice The text of the International Standard ISO9614-2:1996 was
22、approved by CEN as a European Standard without any modification. Contents Page Foreword 2 Introduction 1 1 Scope 2 2 Normative references 2 3 Definitions 3 4 General requirements 5 5 Acoustic environment 6 6 Instrumentation 7 7 Installation and operation of the source 7 8 Measurement of normal sound
23、 intensity component levels 8 9 Calculation of sound power level 10 10 Information to be reported 10 Annex A (normative) Calculation of field indicators 12 Annex B (normative) Procedure for achieving a desired grade of accuracy 12 Annex C (informative) Effects of airflow on measurement of sound inte
24、nsity 15 Annex D (informative) Effect of sound absorption within the measurement surface 15 Annex E (informative) Measurement surface and scanning procedure 16 Annex F (informative) Bibliography 17 Figure 1 Example of a scanning pattern 8 Figure B.1 Scheme for the procedure for achieving the desired
25、 grade of accuracy 14 Figure E.1 Measurement surfaces for typical planar segments 16 Table 1 Bias error factor, K 4 Table 2 Uncertainty in the determination of sound power levels 6 Table B.1 Actions to be taken to increase grade of accuracy of determination 13ENISO9614-2:1996 ii BSI 08-1999 Foreword
26、 ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical
27、 committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of elec
28、trotechnical standardization. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least75% of the member bodies casting a vote. International Standard ISO9614-2 was prepared
29、 by Technical Committee ISO/TC43, Acoustics, Subcommittee SC1, Noise. ISO 9614 consists of the following parts, under the general title Acoustics Determination of sound power levels of noise sources using sound intensity. Part 1: Measurement at discrete points; Part 2: Measurement by scanning; Part
30、3: Precision method for measurement by scanning. Annex A andAnnex B form an integral part of this part of ISO9614. Annex C,Annex D,Annex E andAnnex F are for information only. Descriptors: Acoustics, sound sources, noise (sound), tests, acoustic tests, determination, soundpower, acoustic measurement
31、s.ENISO9614-2:1996 BSI 08-1999 1 Introduction 0.1 The sound power radiated by a source is equal in value to the integral of the scalar product of the sound intensity vector and the associated elemental area vector over any surface totally enclosing the source. Previous International Standards which
32、describe methods of determination of sound power levels of noise sources, principally ISO3740 to ISO3747, without exception specify sound pressure level as the primary acoustic quantity to be measured. The relationship between sound intensity level and sound pressure level at any point depends on th
33、e characteristics of the source, the characteristics of the measurement environment, and the disposition of the measurement positions with respect to the source. Therefore ISO3740 to ISO3747 necessarily specify the source characteristics, the test environment characteristics and qualification proced
34、ures, together with measurement methods which are expected to restrict the uncertainty of the sound power level determination to within acceptable limits. The procedures specified ISO3740 to ISO3747 are not always appropriate, for the following reasons. a) Costly facilities are necessary if high pre
35、cision is required. It is frequently not possible to install and operate large pieces of equipment in such facilities. b) They cannot be used in the presence of high levels of extraneous noise generated by sources other than that under investigation. 0.2 This part of ISO9614 specifies methods of det
36、ermining the sound power levels of sources, within specific ranges of uncertainty, under test conditions which are less restricted than those required by ISO3740 to ISO3747. The sound power level is the in situ sound power level as determined by the procedure of this part of ISO9614; it is physicall
37、y a function of the environment, and may in some cases differ from the sound power level of the same source determined under other conditions. It is recommended that personnel performing sound intensity measurements according to this part of ISO9614 are appropriately trained and experienced. 0.3 Thi
38、s part of ISO9614 complements ISO9614-1 and the series ISO3740 to ISO3747 which specify various methods for the determination of sound power levels of machines and equipment. It differs from the ISO3740 to ISO3747 series principally in three aspects: a) measurements are made of sound intensity as we
39、ll as of sound pressure; b) the uncertainty of the sound power level determined by the method specified in this part of ISO9614 is classified according to the results of specified ancillary tests and calculations performed in association with the test measurements; c) current limitations of intensit
40、y measurement equipment which conforms to IEC1043 restricts measurements to the one-third-octave range50Hz to 6,3kHz; band-limited A-weighted values are determined from the constituent one-octave or one-third-octave band values and not by direct A-weighted measurement. 0.4 The integral over any surf
41、ace totally enclosing the source of the scalar product of the sound intensity vector and the associated elemental area vector provides a measure of the sound power radiated directly into the air by all sources located within the enclosing surface and excludes sound radiated by sources located outsid
42、e this surface. In practice, this exclusion is effective only if the source under test and other sources of extraneous intensity on the measurement surface are stationary in time. In the presence of sound sources operating outside the measurement surface, any system lying within the surface may abso
43、rb a proportion of energy incident upon it. The total sound power absorbed within the measurement surface will appear as a negative contribution to source power, and may produce an error in the sound power determination. In order to minimize the associated error, it is therefore necessary to remove
44、any sound-absorbing material lying within the measurement surface which is not normally present during the operation of the source under test. This method is based on sampling of the intensity field normal to the measurement surface by moving an intensity probe continuously along one or more specifi
45、ed paths. The resulting sampling error is a function of the spatial variation of the normal intensity component over the measurement surface, which depends upon the directivity of the source, the chosen sampling surface, the pattern and speed of the probe scanning, and the proximity of extraneous so
46、urces outside the measurement surface.ENISO9614-2:1996 2 BSI 08-1999 The accuracy of measurement of the normal component of sound intensity at a position is sensitive to the difference between the local sound pressure level and the local normal sound intensity level. A large difference may occur whe
47、n the intensity vector at a measurement position is directed at a large angle (approaching90 ) to the local normal to the measurement surface. Alternatively, the local sound pressure level may contain strong contributions from sources outside the measurement surface, but may be associated with littl
48、e net sound energy flow, as in a reverberant field in an enclosure; or the field may be strongly reactive because of the presence of the near field and/or standing waves. The accuracy of determination of sound power level is adversely affected by a flow of sound energy into the volume enclosed by th
49、e measurement surface through a portion of that surface, even though it is, in principle, compensated by increased flow out of the volume through the remaining portion of the surface. This condition is caused by the presence of a strong extraneous source close to, but outside, the measurement surface. 1 Scope 1.1 This part of ISO9614 specifies a method for measuring the component of sound intensity normal to a measurement surface which is chosen so as to enclose the noise source(s) of which the sound power level is to be determ
