1、BRITISH STANDARD BS EN ISO 266:1997 Acoustics Preferredfrequencies The European Standard EN ISO266:1997 has the status of a British Standard ICS 17.140.01BSENISO266:1997 This British Standard, having been prepared under the directionof the Health and Environment Sector Board, waspublished under the
2、authorityof the Standards Boardand comes into effect on 15November1997 BSI 09-1999 ISBN 0 580 28782 3 National foreword This British Standard is the English language version of EN ISO266:1997. Itis identical with ISO266:1997. It supersedes BS3593:1963 which is withdrawn. The UK participation in its
3、preparation was entrusted to Technical Committee EH/1, Acoustics, which has the responsibility to: aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monit
4、or related international and European developments and promulgate them in the UK. A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references Attention is drawn to the fact that CEN and CENELEC Standards normally include an annex which lists no
5、rmative references to international publications with their corresponding European publications. TheBritishStandards which implement these international or European publications may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or
6、by using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer im
7、munity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, theEN ISO title page, page 2, the ISO title page, pagesii toiv, pages1and2, an inside back cover and a back cover. This standard has been updated (see copyright date) and may
8、 have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Amendments issued since publication Amd. No. Date CommentsBSENISO266:1997 BSI 09-1999 i Contents Page National foreword Inside front cover Foreword 2 Foreword iii Text of ISO266 1ii blankEUROP
9、EAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO266 May 1997 ICS 17.140.01;97.200.20 Descriptors: See ISO document English version Acoustics Preferred frequencies (ISO266:1997) Acoustique Frquences normales (ISO266:1997) Akustik Normfrequenzen (ISO266:1997) This European Standard was approved by
10、CEN on 1997-03-27. 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 standards m
11、ay 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 CEN member into its own language and notified to the Cen
12、tral Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, CzechRepublic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdo
13、m. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1997 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO266:1997 E
14、ENISO266:1997 BSI 09-1999 2 Foreword The text of the International Standard ISO266:1997 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 sta
15、tus of a national standard, either by publication of an identical text or by endorsement, at the latest by November 1997, and conflicting national standards shall be withdrawn at the latest by November 1997. According to the CEN/CENELEC Internal Regulations, the national standards organizations of t
16、he following countries are bound to implement this European Standard: Austria, Belgium, CzechRepublic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the UnitedKingdom. Endorsement notice The text of the I
17、nternational Standard ISO266:1997 was approved by CEN as a EuropeanStandard without any modification.ENISO266:1997 ii BSI 09-1999 Contents Page Foreword iii Introduction 1 1 Scope 1 2 Normative reference 1 3 Definitions 1 4 Preferred frequencies 1 Annex A (informative) Bibliography Inside back cover
18、 Table 1 Preferred frequencies 2ENISO266:1997 BSI 09-1999 iii 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 comm
19、ittees. 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
20、International Electrotechnical Commission (IEC) on all matters of electrotechnical 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 membe
21、r bodies casting a vote. International Standard ISO266 was prepared by Technical Committee ISO/TC43, Acoustics. This second edition cancels and replaces the first edition (ISO266:1975), which has been technically revised. Annex A of this International Standard is for information only. Descriptors: A
22、coustics, acoustic measurements, frequencies.iv blankENISO266:1997 BSI 09-1999 1 Introduction This International Standard specifies a series of preferred frequencies in order to provide a common basis for comparing the results of acoustical measurements. The frequency series is referred to the refer
23、ence frequency of1000Hz, which is also the reference frequency for the definition of the phon (see ISO31-7). The specification of the preferred frequency series reduces to a minimum the number of frequencies at which acoustical data need to be tabulated. Also measurement equipment may be specificall
24、y constructed for these frequencies. The specified series of preferred frequencies uses powers of10 and is therefore especially convenient for extensions into the infrasonic and ultrasonic (frequency) ranges. Another series of frequencies that is in use is based on the definition of the octave as th
25、e frequency ratio1:2. The frequencies of this series are calculated as powers of two (IEC1260 base-two series). Strictly, these two series are incompatible. However the base-two series may be accepted as a sufficient approximation to the base-ten series because of the fact that2 1/3 =1,2599. is very
26、 nearly the same as10 1/10 =1,2589. Practical considerations make some additional rounding desirable: Thus500Hz is listed instead of501,187233.Hz, which is the exact frequency from the base-ten series. The calculated value of the exact frequency expressed to five significant figures is given in the
27、second column of Table 1. In this way, the maximum individual deviation, in the frequency range20Hz to20000Hz, between the rounded preferred frequencies and the calculated frequencies for the base-ten and base-two series is0,94% and1,59%, respectively. 1 Scope This International Standard specifies p
28、referred frequencies for acoustical measurements. The preferred frequencies are based on the R10 series of preferred numbers in ISO3 and the reference frequency of1000Hz. For most acoustical measurements and presentations of data, a frequency spacing based on a constant percentage increment is gener
29、ally preferred and the test frequencies then form a geometric series. For certain acoustical measurements, a constant frequency increment is a suitable spacing. The International Standard deals with the geometric series and is not intended to apply to cases where a constant frequency increment, or o
30、ther particular spacing, would be more suitable, or where there may be good reasons for the adoption or retention of other frequencies. This International Standard does not deal with: frequencies for music; all audiometric frequencies; series other than R10 from ISO3. 2 Normative reference The follo
31、wing standard contains provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publication, the edition indicated was valid. All standards are subject to revision, and parties to agreements based on this International Standard are encour
32、aged to investigate the possibility of applying the most recent edition of the standard indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO3:1973, Preferred numbers Series of preferred numbers. 3 Definitions For the purposes of this Internationa
33、l Standard, the following definitions apply. 3.1 exact frequency frequency, expressed in hertz, which is calculated from the formula: f =10 n/10f r where f ris the reference frequency1000Hz and n is an integer, positive or negative 3.2 calculated frequency frequency approximating to the exact freque
34、ncy, expressed to five significant figures 3.3 preferred frequency frequency equal in magnitude to one of the R10series of preferred numbers defined in ISO3 4 Preferred frequencies 4.1 The preferred frequencies as defined by the R10series are given in Table 1. 4.2 The series of preferred frequencies
35、 given in Table 1 may be extended indefinitely in either direction by successive multiplication or division by powers of ten.ENISO266:1997 2 BSI 09-1999 4.3 Where more precision is needed, the calculated frequency may be used. Values of the calculated frequencies rounded to five significant digits a
36、nd calculated from the formula given in3.1 are also given in Table 1. 4.4 The frequencies of one-octave and one-third-octave intervals based on the reference frequency of1000Hz and approximated by the relevant figures of the R10 series are indicated by crosses in the corresponding columns. NOTESee I
37、EC1260 for the determination of preferred frequencies for other fractional-octave-band intervals. Table 1 Preferred frequencies Preferred frequency a Hz or kHz Calculated frequency Hz or kHz One-octave interval One-third-octaveinterval 1,00 1,25 1,60 2,00 2,50 3,15 4,00 5,00 6,30 8,00 10,0 12,5 16,0
38、 20,0 25,0 31,5 40,0 50,0 63,0 80,0 100 125 160 200 250 315 400 500 630 800 1,0000 1,2589 1,5849 1,9953 2,5119 3,1623 3,9811 5,0119 6,3096 7,9433 10,000 12,589 15,849 19,953 25,119 31,623 39,811 50,119 63,096 79,433 100,00 125,89 158,49 199,53 251,19 316,23 398,11 501,19 630,96 794,33 a This series
39、may be extended. See4.2.ENISO266:1997 BSI 09-1999 Annex A(informative) Bibliography 1 ISO31-7:1992, Quantities and units Part7:Acoustics. 2 IEC1260:1995, Electroacoustics Octave-band and fractional-octave-band filters.BS EN ISO 266:1997 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsIns
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