1、BRITISH STANDARDBS EN ISO 3382-2:2008Acoustics Measurement of room acoustic parameters Part 2: Reverberation time in ordinary roomsICS 91.120.20g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g3
2、7g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58Incorporating April 2009corrigendumNational forewordThis British Standard is the UK implementation of EN ISO 3382-2:2008. It is identical with ISO 3382-2:2008, incorporating corrigendum April 2009. It partially supersedes BS EN ISO 3382:2000, which will be
3、 withdrawn on publication of BS EN ISO 3382-1 and BS EN ISO 3382-3.The UK participation in its preparation was entrusted by Technical Committee EH/1, Acoustics, to Subcommittee EH/1/6, Building acoustics. A list of organizations represented on this subcommittee can be obtained on request to its secr
4、etary. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard cannot confer immunity from legal obligations. BS EN ISO 3382-2:2008This British Standard was published under the auth
5、ority of the Standards Policy and Strategy Committee on 31 October 2008 BSI 2009Amendments/corrigenda issued since publicationDate Comments 31 August 2009 Implementation of ISO corrigendum April 2009. Figure A.2 changedISBN 978 0 580 67763 2EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN ISO 3382-
6、2June 2008ICS 91.120.20 Supersedes EN ISO 3382:2000 English VersionAcoustics - Measurement of room acoustic parameters - Part 2:Reverberation time in ordinary rooms (ISO 3382-2:2008)Acoustique - Mesurage des paramtres acoustiques dessalles - Partie 2: Dure de rverbration des sallesordinaires (ISO 33
7、82-2:2008)Akustik - Messung von Parametern der Raumakustik - Teil2: Nachhallzeit in gewhnlichen Rumen (ISO 3382-2:2008)This European Standard was approved by CEN on 22 May 2008.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this Eu
8、ropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the CEN Management Centre or to any CEN member.This European Standard exists in three official versions (Englis
9、h, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as theofficial versions.CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyp
10、rus, Czech Republic, Denmark, Estonia, Finland,France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT
11、 EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2008 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN ISO 3382-2:2008: EForeword This document (EN ISO 3382-2:2008) has been
12、 prepared by Technical Committee ISO/TC 43 “Acoustics“ in collaboration with Technical Committee CEN/TC 126 “Acoustic properties of building elements and of buildings” the secretariat of which is held by AFNOR. This European Standard shall be given the status of a national standard, either by public
13、ation of an identical text or by endorsement, at the latest by December 2008, and conflicting national standards shall be withdrawn at the latest by December 2008. 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
14、 shall not be held responsible for identifying any or all such patent rights. This document supersedes EN ISO 3382:2000. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium,
15、 Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Endorsement notice The
16、 text of ISO 3382-2:2008 has been approved by CEN as a EN ISO 3382-2:2008 without any modification. BS EN ISO 3382-2:2008iiiiiContents Page Foreword iv Introduction v 1 Scope . 1 2 Normative references . 1 3 Terms and definitions. 1 4 Measurement conditions . 2 4.1 General. 2 4.2 Equipment . 3 4.3 M
17、easurement positions 4 5 Measurement procedures 5 5.1 General. 5 5.2 Interrupted noise method 5 5.3 Integrated impulse response method. 6 6 Evaluation of decay curves . 7 7 Measurement uncertainty 7 7.1 Interrupted noise method 7 7.2 Integrated impulse response method. 8 7.3 Lower limits for reliabl
18、e results caused by filter and detector 8 8 Spatial averaging 8 9 Statement of results . 9 9.1 Tables and curves. 9 9.2 Test report . 9 Annex A (informative) Measurement uncertainty . 10 Annex B (informative) Evaluation of non-linear decay curves 14 Annex C (informative) Formulas for the least-squar
19、es fit method 16 Bibliography . 17 BS EN ISO 3382-2:2008iv Foreword 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 committ
20、ees. Each member body interested in a subject for which a technical 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 Int
21、ernational Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International
22、Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the s
23、ubject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 3382-2 was prepared by Technical Committee ISO/TC 43, Acoustics, Subcommittee SC 2, Building acoustics. ISO 3382-2, together with ISO 3382-1 and ISO 3382-3, cancel and replace ISO 3382:1997.
24、 ISO 3382 consists of the following parts, under the general title Acoustics Measurement of room acoustic parameters: Part 1: Performance rooms Part 2: Reverberation time in ordinary rooms The following part is in preparation: Part 3: Open plan spaces BS EN ISO 3382-2:2008vIntroduction This part of
25、ISO 3382 specifies three levels of measurement accuracy: survey; engineering; and precision. The main difference concerns the number of measurement positions and thus the time required for the measurements. Annex A contains some additional information about the measurement uncertainty of the reverbe
26、ration time. The introduction of the option of a survey measurement is intended to promote more frequent measurement of reverberation time in rooms where it is relevant. It is obvious that a very simple measurement is better than no measurement. There are several reasons to measure reverberation tim
27、e. First, the sound pressure level from noise sources, the intelligibility of speech, and the perception of privacy in a room are strongly dependent on reverberation time. Rooms may include domestic rooms, stairways, workshops, industrial plants, classrooms, offices, restaurants, exhibition centres,
28、 sports halls, and railway and airport terminals. Second, reverberation time is measured to determine the correction term for room absorption inherent in many acoustic measurements, such as sound insulation measurements according to ISO 140 (all parts) and sound power measurements according to ISO 3
29、740. In some countries, building codes specify the required reverberation times in classrooms and other categories of room. However, in the vast majority of rooms, it is left to the design team to specify and design for a reverberation time that is reasonable for the purpose of a room. This part of
30、ISO 3382 is intended to contribute to the general understanding and acceptance of reverberation time for room quality and usability. Two different evaluation ranges are defined in this part of ISO 3382, 20 dB and 30 dB. However, a preference has been given to the 20 dB evaluation range for several r
31、easons: a) the subjective evaluation of reverberation is related to the early part of the decay; b) for the estimation of the steady-state sound level in a room from its reverberation time, it is appropriate to use the early part of the decay: and c) the signal-to-noise ratio is often a problem in f
32、ield measurements, and it is often difficult or impossible to get a evaluation range of more than 20 dB. This requires a signal-to-noise level of at least 35 dB. The traditional measuring technique is based on visual inspection of every single decay curve. With modern measuring equipment, the decay
33、curves are normally not displayed and this may introduce a risk that abnormal decay curves are used for the determination of the reverberation time. For this reason, Annex B introduces two new measures that quantify the degree of non-linearity and the degree of curvature of the decay curve. These me
34、asures may be used to give warnings when the decay curve is not linear, and consequently the result should be marked as less reliable and not having a unique reverberation. The use of rotating microphones during the measurement of decay curves has been considered by the working group, and this proce
35、dure is found to be without a clear physical meaning and thus it is only accepted for the interrupted noise method and only when the result is used for a correction term. For other reverberation time measurements, ISO 3382-1 covers auditoria and performance spaces, and ISO 354 absorption coefficient
36、 measurements in a reverberation room. Neither ISO 3382-1 nor ISO 354 is suitable for measurements in rooms like those mentioned above. Thus, this part of ISO 3382 fills a gap among measurement standards for acoustic properties of buildings. This part of ISO 3382 does not repeat the technical detail
37、s of ISO 3382-1, but deals with the measurement of reverberation time, only, in any kind of room. BS EN ISO 3382-2:2008blank1Acoustics Measurement of room acoustic parameters Part 2: Reverberation time in ordinary rooms 1 Scope This part of ISO 3382 specifies methods for the measurement of reverbera
38、tion time in ordinary rooms. It describes the measurement procedure, the apparatus needed, the required number of measurement positions, and the method for evaluating the data and presenting the test report. The measurement results can be used for correction of other acoustic measurements, e.g. soun
39、d pressure level from sound sources or measurements of sound insulation, and for comparison with requirements for reverberation time in rooms. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cite
40、d applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 3382-1:1), Acoustics Measurement of room acoustic parameters Part 1: Performance rooms ISO 18233, Acoustics Application of new measurement methods in building and room acoustics I
41、EC 61260, Electroacoustics Octave-band and fractional-octave-band filters 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 decay curve graphical representation of the decay of the sound pressure level in a room as a function of time after the
42、sound source has stopped ISO 354:2003, 3.1 NOTE It is possible to measure this decay either after the actual cut-off of a continuous sound source in the room or derived from the reverse-time integrated squared impulse response of the room, see Clause 5. 1) To be published. (Revision of ISO 3382:1997
43、) BS EN ISO 3382-2:20082 3.2 interrupted noise method method of obtaining decay curves by direct recording of the decay of sound pressure level after exciting a room with broadband or band-limited noise ISO 354:2003, 3.3 3.3 integrated impulse response method method of obtaining decay curves by reve
44、rse-time integration of squared impulse responses ISO 354:2003, 3.4 3.4 impulse response temporal evolution of the sound pressure observed at a point in a room as a result of the emission of a Dirac impulse at another point in the room ISO 354:2003, 3.5 NOTE It is impossible in practice to create an
45、d radiate true Dirac delta functions but short transient sounds (e.g. from gunshots) can offer close enough approximations for practical measurement. An alternative measurement technique, however, is to use a period of maximum-length sequence (MLS) type signal or other deterministic, flat-spectrum s
46、ignal like a sine sweep and transform the measured response back to an impulse response. 3.5 reverberation time T room acoustic parameters duration required for the space-averaged sound energy density in an enclosure to decrease by 60 dB after the source emission has stopped NOTE 1 The reverberation
47、 time is expressed in seconds. NOTE 2 T can be evaluated based on a smaller dynamic range than 60 dB and extrapolated to a decay time of 60 dB. It is then labelled accordingly. Thus, if T is derived from the time at which the decay curve first reaches 5 dB and 25 dB below the initial level, it is la
48、belled T20. If decay values of 5 dB to 35 dB below the initial level are used, it is labelled T30. 3.6 large room volume an enclosed space of volume greater than 300 m34 Measurement conditions 4.1 General In many rooms, the number of people present can have a strong influence on the reverberation ti
49、me. Reverberation time measurements should be made in a room containing no people. However, a room with up to two persons present may be allowed to represent its unoccupied state, unless otherwise specified. If the measurement result is used for correction of a measured sound pressure level, the number of persons present in the room should be the same for that measurement. In large rooms, attenuation by air can contribute significantly to sound absorption at high frequencies. For precision measurements, the temperature and relative humidit
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