1、STD.BSI BS EN IS0 2bb-ENGL 1997 1b24bb7 Ob599b7 IT9 BRITISH STANDARD Acoustics - Preferred frequencies The European Standard EN IS0 266 : 1997 has the status of a Brikh Standard ICs 17.140.01 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW IS EN IS0 I66 : 1997 - STDSBSI BS EN
2、IS0 2bb-ENGL 1997 D Lb24bb9 Ob599bA 035 Amd. No. BS EN IS0 266 : 1997 Date Text affected This British Standard, having been prepared under the direction of the Health and Environment Sedor Board, was published under the authority of the Standards Board and comes into effect on 15 November 1997 O BSI
3、 1997 National foreword This British Standard is the English language version of EN IS0 266 : 1997. It is identical with IS0 266 : 1997. It supersedes BS 3593 : 1963 which is withdrawn. The UK participation in its preparation was entnisted to Technical Committee Ew1, Acoustics, which has the respons
4、ibility to: - aid enquirem to undemtand the text, - present to the responsible internationaUT3uropean committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; - monitor related international and European developments and promulgate them in the UK. A
5、 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 normative references to internationai publications with their corresponding European
6、publications. The British Standards which implement these international or European publications may be found in the BSI Standards Catalogue under the section entitied International Standards Correspondence Index, or by using the J?ind facility of the BSI Standards Electronic Catalogue. Compliance w
7、ith a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, the EN IS0 title page, the EN IS0 foreword page, the IS0 title page, pages ii and iii, a blank page, pages 1 to 3, a blank page, an inside
8、back cover and a back cover. Amendments issued since publication ISBN O 580 28782 3 STD.BS1 BS EN IS0 2bb-ENGL 1997 lb24bb9 Ob599b9 T7L EUROPEAN STANDARD NORME EUROPEENNE EUROPISCHE NORM - EN IS0 266 May 1997 ICs 17.140.01; 97.200.20 Descriptors: See IS0 document English version Acoustics - Preferre
9、d frequencies (IS0 266: 1997) Acoustique - Frquences normales (IS0 266:1997) Akustik - Normfrequenzen (IS0 266:1997) This European Standard was approved by CEN on 1997-03-27. CEN members are bound to comply uith the CEN/CENELEC Internal Regulations uhich stipulate the conditions for giving this Euro
10、pean 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. lhe European Standards exist in three official versions (English,
11、 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 rhe official versions. CEN members are the national standards bodies of Austria, Belgiun, Czech Republic
12、, Dermark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sueden, Switzerland and United K i ngdom . CEN European Comnittee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: puc de Stas
13、sart,= B-1050 Brussels 0 1997 CEN - All rights of exploitation in any form and by any means reserved uorlduide for CEN national Mmibers. Ref. No. EN IS0 266:1997 E STD-BSI BS EN IS0 2bb-ENGL 1997 Lb24bb7 0b59770 793 EN IS0 266 : 1997 Foreword The text of the International Standard IS0 266:1997 has b
14、een prepared by Technical Committee ISOTTC 43 “Acoustics“ in collaboration with Technical Committee CEN/TC 2 1 1 “Acoustics“, the secretariat of which is held by DS. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement,
15、 at the latest by November 1997, and conflicting national standards shall be withdrawn at the latest by November 1997. According to the CENKENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Cz
16、ech Republic, 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 Standard IS0 266: 1997 was approved by CEN as a European Standard without a
17、ny modification. STD-BSI BS EN IS0 2bb-ENGL 1997 W 1b24bb9 Ob59971 b2T EN IS0 266 : 1997 INTERNATIONAL STANDARD IS0 266 Second edition 1997-04-01 - - Acoustics - Preferred frequencies Acoustique - Frquences normales Reference number IS0 266:1997(E) STD-BSI BS EN IS0 Zbb-ENGL 1777 U LbZLibbS Ob57772
18、5bb EN IS0 266 : 1997 Foreword IS0 (the International Organization for Standardization) is a worldwide federation of national standards bodies (IS0 member bodies). The work of preparing International Standards is normally carried out through IS0 technical committees. Each member body interested in a
19、 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. IS0 collaborates closely with the International Electrotechnical Commissi
20、on (IEC) on all matters of electrotechnical standardization. Draf International 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. International
21、 Standard IS0 266 was prepared by Technical Committee ISO/TC 43, Acoustics. This second edition cancels and replaces the first edition (IS0 266:1975), which has been technically revised. Annex A of this International Standard is for information only. Descriptors: Acoustics, acoustic measurements, fr
22、equencies. ii * * v, STD-BSI BS EN IS0 2bb-ENGL 1997 W Lb2Libb7 Ob59973 4T2 D EN IS0 266 : 1997 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 referr
23、ed to the reference frequency of 1 O00 Hz, which is also the reference frequency for the definition of the phon (see 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 spe
24、cifically constructed for these frequencies. The specified series of preferred frequencies uses powers of 10 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 oct
25、ave as the frequency ratio 1:2. The frequencies of this series are calculated as powers of two (IEC 1260 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 that 2” = 1,25
26、9 9. is very nearly the same as IS0 31 -7). 1 Oo = 1,258 9 . Practical considerations make some additional rounding desirable: Thus 500 Hz is listed instead of 501,187 233 . Hz, which is the exact frequency from the base-ten series. The calculated value of the exact frequency expressed to five signi
27、ficant figures is given in the second column of table 1. In this way, the maximum individual deviation, in the frequency range 20 Hz to 20 O00 Hz, between the rounded preferred frequencies and the calculated frequencies for the base-ten and base-two series is 0,94 YO and 1,59 YO, respectively. iii S
28、TD.BS1 BS EN IS0 2bb-ENGL 1777 m Lb24bb7 Ob59774 337 m EN IS0 266 : 1997 Acoustics - Preferred frequencies 1 scope This International Standard specifies preferred frequencies for acoustical measurements. The preferred frequencies are based on the R10 series of preferred numbers in IS0 3 and the refe
29、rence frequency of 1 000 Hz. For most acoustical measurements and presentations of data, a frequency spacing based on a constant percentage increment is generally preferred and the test frequencies then form a geometric series. For certain acoustical measurements, a constant frequency increment is a
30、 suitable spacing. The International Standard deals with the geometric series and is not intended to apply to cases where a constant frequency increment, or other particular spacing, would be more suitable, or where there may be good reasons for the adoption or retention of other frequencies. This I
31、nternational Standard does not deal with: - frequencies for music; - all audiometric frequencies; - series other than R10 from IS0 3. 2 Normative reference The following standard contains provisions which, through reference in this text, constitute provisions of this International Standard. At the t
32、ime of publication, the edition indicated was valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent edition of the standard indicated below. Members of IEC and IS0 maintai
33、n registers of currently valid International Standards. IS0 311 973, Preferred numbers - Series of preferred numbers. 3 Definitions For the purposes of this International Standard, the following definitions apply. 3.1 exact frequency: Frequency, expressed in hertz, which is calculated from the formu
34、la: f = 10“/0 fr where fr is the reference frequency 1 O00 Hz and n is an integer, positive or negative. 3.2 calculated frequency: Frequency approximating to the exact frequency, expressed to five significant figures. 3.3 preferred frequency: Frequency equal in magnitude to one of the FI10 series of
35、 preferred numbers defined in IS0 3. 1 STD-BSI BS EN IS0 2bb-ENGL 1797 Lb24bb9 Ub59775 275 D Preferred frequency 1 ) Hz or kHz 1 ,o0 1,25 1,60 2,oo 2,50 3,15 4,OO 5,00 6,30 8,OO 10,o 12,5 16,O 20,o 25,O 31,5 40,O 50,O 63,O 80,O 1 O0 125 160 200 250 31 5 400 500 630 800 1) This series may be extended
36、. See 4.2. EN IS0 266 : 1997 4 Preferred frequencies 4.1 The preferrred frequencies as defined by the R10 series are given in table 1 4.2 The series of preferred frequencies given in table 1 may be extended indefinitely in either direction by successive multiplication or division by powers of ten. 4
37、.3 Where more precision is needed, the calculated frequency may be used. Values of the calculated frequencies rounded to five significant digits and calculated from the formula given in 3.1 are also given in table 1. 4.4 The frequencies of one-octave and one-third-octave intervals based on the refer
38、ence frequency of 1 O00 Hz and approximated by the relevant figures of the R10 series are indicated by crosses in the corresponding columns. NOTE - See IEC 1260 for the determination of preferred frequencies for other fractional-octave-band intervals. Table 1 - Preferred frequencies Calculated frequ
39、ency Hz or kHz 1,000 o 1.258 9 1,584 9 1,995 3 2,511 9 3,162 3 3,981 1 5,011 9 6,309 6 7,943 3 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 31 6,23 398,ll 501,19 630,96 794,33 Oneoctave Interva X X X X X X X X X X One-thirdoctave interval X
40、 X X X X X X X X X X X X X X X X X X X X X X X X X X X X X 2 STD-BSI BS EN IS0 2bb-ENGL 1977 lb24bb7 Ob5797b 101 = EN IS0 266 : 1997 Annex A (informative) Bibliography l IS0 31-7:1992, Quantities and units - Par? 7: Acoustics. 2 IEC 1260:1995, Electroacoustics - Octave-band and fractional-octave-ban
41、d fiiters. * m * 3 BSEN IS0 266 : 1997 BSI 389 Chiswick High Roa London w4 4AL BSI - British Standards Institution BSI is the independent national body responsible for preparing British Standards. It presents the UK view on standards in Europe and at the international level. It is incorporated by Ro
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