1、ICs 17.140.01 Descriptors: Acoustics, frequencies. Akustik - Normfrequenzen (IS0 266: 1997) Supersedes DIN 45401, February 1985 edition. European Standard EN IS0 266: 1997 has the status of a DIN Standard. A comma is used as the decimal marker. National foreword This standard has been published in a
2、ccordance with a decision taken by CEN/TC 21 1 to adopt, without alteration, International Standard IS0 266 as a European Standard. The responsible German body involved in its preparation was the Normenausschu Akustik, irmminderung und Schwingungstechnik (Acoustics, Noise Control and Vibration Engin
3、eering Standards Committee). It should be noted that the 1997 edition of IS0 266 is largely based on DIN 45401. The DIN Standards corresponding to the International Standards referred to in clause 2 of the EN are as follows: International Standard DIN Standard IEC 1260 DIN EN 61260 IS0 3 DIN 323-1 I
4、S0 31-7 DIN IS0 31-7*) Amendments DIN 45401, November 1985 edition, has been superseded by the specifications of EN IS0 266, which is identical to IS0 266. Previous editions DIN 45401: 1960-06, 1970-03, 1985-02. National Annex NA Standards referred to (and not included in Normative reference) DIN 32
5、3-1 Preferred numbers and preferred number series - Basic, calculated and rounded values Electroacoustics - Octave-band and fractional octave-band filters DIN EN 61260 *) At present at the stage of draft. EN comprises 5 pages. Q No pari of this standard may be reproduced without the prior permission
6、 of DIN Deutsches Institut fr Normung e.V., Berlin. Beuth Verlag GmbH, Berlin, has the exclusive right of sale for German Standards (DIN-Normen) Ref. No. DIN EN IS0 266: 1997-0 English price group 06 Sales No. 1106 01.98 EU ROPEAN STAN DAR D EUROPISCHE NORM NORME EUROPENNE EN IS0266 May 1997 ICs 17.
7、140.01; 97.200.20 Descriptors: Acoustics, frequencies. English version Acoustics Preferred 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 w
8、ith the CENLENELEC 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 may be obtained on application to the Central Secretar
9、iat 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 Central Secretariat has the same status as the official
10、versions. CEN members are the national standards bodies of Austria, Belgium, the Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, the Netherlands, Norway, Portugal, Spain, Sweden, Switzerland, and the United Kingdom. CEN European Committee for Standardi
11、zation Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels O 1997. CEN - All rights of exploitation in any form and by any means reserved worldwide for CEN national members. Ref. No. EN IS0 266: 1997 E Page 2 EN IS0 266 : 1997 Forewo
12、rd International Standard IS0 266: 1997 Acoustics - Preferred frequencies, 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 DS, as a European Standard. T
13、his 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 November 1997 at the latest. In accordance with the CENLENELEC Internal Regulations, the following countries are boun
14、d to implement this European Standard: Austria, Belgium, the Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, the Netherlands, Norway, Portugal, Spain, Sweden, Switzerland, and the United Kingdom. Endorsement notice The text of the International Standar
15、d IS0 266: 1997 was approved by CEN as a European Standard without any modification. 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 r
16、eference 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 specifically c
17、onstructed 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 octave as the
18、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 213 = 1,259 Q. is ve
19、ry nearly the same as 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 significant figures is given in the second c
20、olumn 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 o/o and 1,59 %, respectively. IS0 31 -7). 10” = 1,258 9 . Page 3 EN IS0 26
21、6:1997 Acoustics - Preferred frequencies 1 Scope This International Standard specifies preferred frequencies for acoustical measurements. The preferred frequencies are based on the R1 O series of preferred numbers in IS0 3 and the reference frequency of 1 O00 Hz. For most acoustical measurements and
22、 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 suitable spacing. The International Standard deals with the geom
23、etric 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 International Standard does not deal with: - frequencies for music
24、; - all audiometric frequencies; - series other than RIO 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 time of publication, the edition indicated was valid. All standard
25、s 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 maintain registers of currently valid International Standards. IS0 3:197
26、3, Preferred numbers - Series ofpreferred 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 formula: f= 10n”Ofr wheref, is the reference frequency 1 O00 Hz and IZ i
27、s 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 R10 series of preferred numbers defined in IS0 3. Page 4 EN IS0 266: 1997 4 Preferr
28、ed 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. 4.3 Where more precision is needed, th
29、e 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 I. 4.4 The frequencies of one-octave and one-third-octave intervals based on the reference frequency of 1 O00 Hz and approx
30、imated 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 Preferred frequency) Hz or kHz 1 ,o0 1,25 1,60 2,oo 2
31、,50 3,15 4,OO 5,OO 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 Calculated frequency 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 79,43
32、3 100,oo 125,89 158,49 199,53 251,19 31 6,23 398,ll 501,19 630,96 794,33 he-octave interval X X X X X X X X X X One-t hi rd-octave interval 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 X I This series rnav be extended. See 4.2. Page 5 EN 180266:1997 Annex A (informative) Bibliography l IS0 31-7:1992, Quantities and units - Part 7: Acoustics. 2 IEC 1260: 1995, Electroacoustics - Octave-band and fractional-octave-band filters.
