《ISO-1683-1983.pdf》由会员分享，可在线阅读，更多相关《ISO-1683-1983.pdf（4页珍藏版）》请在三一文库上搜索。
1、International Standard INTERNATIONAL ORGANIZATION FOR STANOARDIZATION*MEYHAPO/JHAR OPAHkt3AlWlR ll0 CTAHAAPTH3AHHWRGANlSATlON INTERNATIONALE DE NORMALlSATlON Acoustics - Preferred reference quantities for acoustic levels Acoustique - Grandeurs normales de rkfhrence pour /es niveaux acoustiques First
2、 edition - 1963-10-01 UDC 634.6 Ref. No. IS0 1663-1963 (E) Descriptors : acoustics, acoustic measurement, sound pressure quantities, units of measurement. Price based on 2 pages Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical St
3、andards 1/9972545001 Not for Resale, 04/25/2007 20:10:16 MDTNo reproduction or networking permitted without license from IHS -,-,- Foreword IS0 (the International Organization for Standardization) is a worldwide federation of national standards bodies (IS0 member bodies). The work of developing Inte
4、rnational Standards is carried out through IS0 technical committees. Every member body interested in a subject for which a technical committee has been authorized has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, a
5、lso take part in the work. Draft International Standards adopted by the technical committees are circulated to the member bodies for approval before their acceptance as International Standards by the IS0 Council. International Standard IS0 1663 was developed by Technical Committee ISO/TC 43, Acousti
6、cs, and was circulated to the member bodies in December 1976. It has been approved by the member bodies of the following countries : Australia India Austria Ireland Belgium Israel Canada Korea, Rep. of Czechoslovakia Mexico Denmark Netherlands Finland New Zealand France Norway Germany, F. R. Poland
7、Romania South Africa, Rep. of Spain Sweden Switzerland United Kingdom USSR The member bodies of the following countries expressed disapproval of the document on technical grounds : Japan USA International Organization for Standardization, 1983 0 Printed in Switzerland Copyright International Organiz
8、ation for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/25/2007 20:10:16 MDTNo reproduction or networking permitted without license from IHS -,-,- INTERNATIONAL STANDARD IS0 1683-1983 (El Acoustics - Preferred reference quant
9、ities for acoustic levels 0 Introduction 0.1 Various kinds of levels expressed in decibels have become common for acoustic measurements in gases, liquids and solid structures. A reference quantity, which is preferably independent of the medium, is needed for each kind of level. For airborne sound, a
10、 special reference sound pressure is preferred according to widespread use and legal implication. 6.2 For several kinds of levels, different reference quantities have been used from time to time. Thus, for clarity, it is necessary to indicate which reference quantity is being employed. 6.3 The magni
11、tude of a reference quantity determines whether the level for a particular variable quantity is positive or negative. For general measurements and many engineering specifications, it is desirable that levels of a given kind be con- sistently positive (or consistently negative) rather than both posit
12、ive and negative. 6.4 In general, a reference quantity should have a magnitude of one and its unit should be a derived SI unit formed by the use of an SI prefix for example micronewton (pN), nanometer per second (nm/s), picowatt (pW)l. See IS0 1ooO. 0.5 Only one reference quantity should apply for e
13、ach given kind of level. 0.6 The purpose of this International Standard is the adop- tion of a preferred set of reference quantities of convenient magnitudes. This International Standard provides standard reference quantities for use when and if levels are employed. The use of levels is not made man
14、datory. 1 Scope and field of application This International Standard specifies reference quantities and gives definitions of some levels for acoustics. It applies to oscillatory quantities. 2 References IS0 3112, Quantities and units of periodic and related phenomena. IS0 3117, Quantities and units
15、of acoustics. IS0 IOCQ, SI units and recommendations for the use of their multiples and of certain other units. IS0 2041, Vibration and shock - Vocabulary. IEC Publication 27-3, Letter symbols to be used in electrical technology - Part 3 : Logarithmic quantities and units. 3 Definitions 3.1 acoustic
16、 levels : see table 1. Various acoustic levels ex- pressed in decibels are listed in table 1. When the multiplying factor is twenty, the numerator of the ratio is understood to be a root-mean-square value of a field quantity, unless otherwise specified. When the multiplying factor is ten, the numera
17、tor of the ratio is understood to be a time average value of a power- like quantity unless otherwise specified. For definitions of levels, see IS0 31/2, IS0 31/7 and IS0 2041. 3.2 decibel : See IS0 31/2, IS0 31/7 and IS0 2041. 1 Copyright International Organization for Standardization Provided by IH
18、S under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/25/2007 20:10:16 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 1683-1983 (E) 3.3 reference quantity : The denominator of the ratio whose logarithm is taken to form a level. See
19、table 1. Table 1 - Various acoustic levels expressed in decibels Designation Definition Sound pressure level Lp = 20 lg (p/p,) dB Vibratory velocity level L, = 20 lg (v/v,) dB Vibratory acceleration level L, = 20 lg (ala,) dB Vibratory force level LF = 20 lg (F/F,) dB Power level Lw= 10 lg (PIP,) dB
20、 Intensity level LI = 10 lg U/I, dB Energy density level L, = 10 lg (w/w,) dB Energy level LE = 10 lg LEIE,) dB I NOTE - For power level, the symbol Lp may also be used. 4 Reference quantities 4.1 Preferred reference quantities Preferred reference quantities expressed in SI units are listed in table
21、 2. 4.2 Sound pressure reference quantity Two reference quantities for sound pressure are listed in table 2. One is to be used exclusively for airborne sound, even though not in accordance with 0.4; it is preferred because of its widespread current use and its legal status in defining allowable soun
22、d pressure levels. The other is to be used for sound in all media other than air. 4.3 Vibratory velocity reference quantity One reference vibratory velocity is listed in table 2. The value of 1 rim/s is based on the current estimate of minimum expected vibratory velocity that is in accordance with 0
23、.3 and 0.4. NOTE - For airborne and structure-borne sound, a reference velocity of higher value, 59 rim/s, is also in use. This has the property that the intensity level, the sound pressure level and the vibratory velocity level for a progressive plane wave in air are almost equal in magnitude. Howe
24、ver, the requirements of 0.4 and 0.5 are not fulfilled. 4.4 Vibratory acceleration reference quantity One reference vibratory acceleration is listed in table 2. The value of 1 pm/s2 is based on the current estimate of minimum expected vibratory acceleration that is in accordance with 0.3 and 0.4. NO
25、TE - For structure-borne sound, a reference acceleration of higher value, 10 vm/s2, is also in use. However, the requirements of 0.4 and 0.5 are not fulfilled. 4.5 Notation for expressing the reference of a level A reference quantity may be introduced by re, which indicates that the level is “with r
26、eference to” and may be so read (see IEC Publication 27-3). For example, “the sound power level, re 1 pW, is equal to 135 df3”. Table 2 - Preferred reference quantities expressed in SI units I Medium Reference quantity Air P o = 20 pPa = 2 x lo-5Pa Media other than air p. = 1 PPa = IO-a Pa All media
27、 a o = 1 pm/s2 = 10-s m/s2 V o = 1 rim/s = 10-g m/s F, = 1 pN = 10-6 PO = 1 pw = IO-12W I, = 1 pW/m2= lo-12W/m2 w, = 1 pJ/m3 = lo-12 J/m3 E, = 1 pJ = IO-12 J Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/25/2007 20:10:16 MDTNo reproduction or networking permitted without license from IHS -,-,-