1、 Reference number ISO/TR 25417:2007(E/R)ISO 2007TECHNICAL REPORT ISO/TR25417First editioneoe 2007-12-01Acoustics Definitions of basic quantities and terms ISO/TR 25417:2007(E/R) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobes licensing policy, this file may be
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6、o e. COPYRIGHT PROTECTED DOCUMENT ISO 2007 The reproduction of the terms and definitions contained in this International Standard is permitted in teaching manuals, instruction booklets, technical publications and journals for strictly educational or implementation purposes. The conditions for such r
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9、 , , , . ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland/Oeaao ea ii ISO 2007 All rights reserved/ ISO/TR 25417:2007(E/R) ISO 2007 All rights reserved/ iiiForeword ISO (the Internatio
10、nal 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 committees. Each member body interested in a subject for which a technical committee has been
11、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 International Electrotechnical Commission (IEC) on all matters of electrotechnical standar
12、dization. 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 Standards adopted by the technical committees are circulated to the member bodies for v
13、oting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. In exceptional circumstances, when a technical committee has collected data of a different kind from that which is normally published as an International Standard (“state of the ar
14、t”, for example), it may decide by a simple majority vote of its participating members to publish a Technical Report. A Technical Report is entirely informative in nature and does not have to be reviewed until the data it provides are considered to be no longer valid or useful. Attention is drawn to
15、 the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO/TR 25417 was prepared by Technical Committee ISO/TC 43, Acoustics, Subcommittee SC 1, Noise. ISO/TR 25417:2007(E/R) iv
16、 ISO 2007 All rights reserved/ () (- ). . - . , , . () . , /, 2. . , , -. 75 % -. , , , , . , . , . . O/TR 25417 O/T 43, , 1, . ISO/TR 25417:2007(E/R) ISO 2007 All rights reserved/ vIntroduction This Technical Report is primarily intended for terminology harmonization within documents prepared by Te
17、chnical Committee ISO/TC 43, Acoustics, Subcommittee SC 1, Noise. Other users, however, may find it of use. This Technical Report currently lists a select number of basic quantities and terms. If appropriate, further items may be added later. The definitions apply to aspects of linear sound in isotr
18、opic fluidic media (unbounded liquids and gases without streaming), and where the effects of non-linearity, anisotropy, non-fluidity and superimposed flow are of minimal concern. The definitions are essentially consistent with ISO 80000-8. ISO/TR 25417:2007(E/R) vi ISO 2007 All rights reserved/ , ,
19、O/T 43, , 1, . , , . . . ( ), , , . 80000-8. TECHNICAL REPORT ISO/TR 25417:2007(E/R) ISO 2007 All rights reserved/ 1Acoustics Definitions of basic quantities and terms 1 Scope 1 This Technical Report specifies definitions of acoustical quantities and terms often used in documents on noise measuremen
20、t prepared by Technical Committee ISO/TC 43, Acoustics, Subcommittee SC 1, Noise, together with their symbols and units. The main purpose is to harmonize the terminology used in documents prepared by ISO/TC 43/SC 1, thus to avoid proliferation of diverging definitions. However, this Technical Report
21、 may be applied to other purposes as well. , , O/T 43, , 1, , . , , O/T 43/ 1, , . , , . 2 Definitions 2 2.1 sound pressure p difference between instantaneous total pressure and static pressure ISO 80000-8:2007, 8-9.2 NOTE 1 Sound pressure is expressed in pascals. NOTE 2 The symbol, p, is often used
22、 without modification to represent a root-mean-square sound pressure. However, root-mean-square values should be indicated by the subscript “eff”. 2.1 p 80000-8:2007, 8-9.2 1 . 2 , , - . eff. ISO/TR 25417:2007(E/R) 2 ISO 2007 All rights reserved/ 2.2 sound pressure level Lpten times the logarithm to
23、 the base 10 of the ratio of the square of the sound pressure, p, to the square of a reference value, p0, expressed in decibels 22010lg dBppLp= where the reference value, p0, is 20 Pa NOTE 1 Because of practical limitations of the measuring instruments, p2is always understood to denote the square of
24、 a frequency-weighted, frequency-band-limited or time-weighted sound pressure. If specific frequency and time weightings as specified in IEC 61672-1 and/or specific frequency bands are applied, this should be indicated by appropriate subscripts; e.g. Lp,AF denotes the A-weighted sound pressure level
25、 with time weighting F. NOTE 2 This definition is technically in accordance with ISO 80000-8:2007, 8-22. 2.2 Lp , p, , p0, 22010lgppLp= , p0= 20 1 , - , p2 , , . 61672-1 / , ; ,Lp,AF A F . 2 - 80000-8:2007, 8-22. 2.3 time-averaged sound pressure level Lp,Tequivalent continuous sound pressure levelLp
26、,eqTten times the logarithm to the base 10 of the ratio of the time average of the square of the sound pressure, p, during a stated time interval of duration, T (starting at t1and ending at t2), to the square of a reference value, p0, expressed in decibels ()212,eq201d10lg dBttpT p TpttTLLp=where th
27、e reference value, p0, is 20 Pa NOTE 1 Because of practical limitations of the measuring instruments, p2is always understood to denote the square of a frequency-weighted and frequency-band-limited sound pressure. If a specific frequency weighting as specified in IEC 61672-1 and/or specific frequency bands are applied, this should be indicated by appropriate subscripts; e.g. Lp,A,10 sdenotesthe A-weighted time-averaged sound pressure level over 10 s. 2.3 Lp,T Lp,eqT , p, , T ( t1 t2), , p0, ()212,eq201d10lgttpT p Tp ttTLLp = , p0= 20 1 , , p2 , . 61672-1 / , ;
