1、 Reference number ISO 13474:2009(E) ISO 2009INTERNATIONAL STANDARD ISO 13474 First edition 2009-06-15 Acoustics Framework for calculating a distribution of sound exposure levels for impulsive sound events for the purposes of environmental noise assessment Acoustique Cadre pour le calcul dune distrib
2、ution des niveaux dexposition sonore pour les sons impulsionnels pour les besoins de lvaluation du bruit environnemental ISO 13474:2009(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobes licensing policy, this file may be printed or viewed but shall not be edit
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7、pyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2009 All rights reservedISO 13474:2009(E) ISO 2009 All rights reserved iiiContents Page Foreword .v Introductionvi 1 Scope1 2 Normative references1 3 Terms and definitions .2 4 Basic equations .6 4.1 General .6 4.2 Probability of occurre
8、nce .6 4.3 Band sound exposure level7 4.4 Frequency-weighted sound exposure level8 4.5 Long-term average single-event sound exposure level8 4.6 Equivalent level from multiple events.10 5 Calculation of a statistical distribution .10 6 Calculation of attenuation 14 6.1 General .14 6.2 Geometric diver
9、gence.14 6.3 Atmospheric absorption.14 6.4 Insertion loss by screening objects 15 6.5 Terrain shielding15 6.6 Contributions to excess attenuation.16 6.6.1 General .16 6.6.2 Refraction.16 6.6.3 Ground reflection and absorption .17 7 Classification .19 7.1 General .19 7.2 Classification of atmospheric
10、 absorption.19 7.3 Classification of excess attenuation .19 7.3.1 General .19 7.3.2 Lookup table requirements 20 7.3.3 Range-dependent sound speed profiles.21 7.3.4 Directed sound speed profiles.21 8 Probability of occurrence of sound speed profiles .22 8.1 General .22 8.2 Using direct measurements
11、of wind and temperature profiles 22 8.3 Similarity relationships for the atmospheric surface layer.23 8.4 Using measurements of turbulent fluxes24 8.5 Using routinely gathered weather station data 25 8.6 Using directly measured or calculated sound speed profiles as input .26 9 The source .26 9.1 Gen
12、eral .26 9.2 Demolition and muzzle blasts 26 9.2.1 General .26 9.2.2 Source descriptors27 9.2.3 Determination by measurement.27 9.2.4 Determination by estimation 28 9.3 Projectile sound.28 9.3.1 General .28 ISO 13474:2009(E) iv ISO 2009 All rights reserved9.3.2 Flat trajectories 28 9.3.3 High-elevat
13、ion trajectories and rocket trajectories28 10 Uncertainties 28 Annex A (informative) Example of the estimation of the statistical distribution of single-event sound exposure levels 30 Annex B (informative) Uncertainty 37 Bibliography 40 ISO 13474:2009(E) ISO 2009 All rights reserved vForeword ISO (t
14、he 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 committees. Each member body interested in a subject for which a technical commit
15、tee 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 International Electrotechnical Commission (IEC) on all matters of electrotech
16、nical standardization. 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
17、 bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to 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
18、 any or all such patent rights. ISO 13474 was prepared by Technical Committee ISO/TC 43, Acoustics, Subcommittee SC 1, Noise. It cancels and replaces ISO/TS 13474:2003, which has been technically revised. ISO 13474:2009(E) vi ISO 2009 All rights reservedIntroduction The aim of this International Sta
19、ndard is to provide a framework for the evaluation of descriptor quantities for use in environmental noise assessment. Part of this framework includes an engineering method for calculating a statistical distribution of event sound exposure levels at locations which are some distance from high-energy
20、 impulsive sound sources. It is specifically intended for environmental noise assessment and not for the assessment of the risk of damage to buildings or the risk of injury to animals or people. In ISO 9613-2, the immission level from sources such as traffic and industry is calculated for a so-calle
21、d “downwind” condition. The long-term average level is estimated using a correction factor, C met . This concept holds for distances where sound from such sources is assessed as environmental noise. ISO 9613-2 excludes impulses in its scope and holds only for A-weighting, for near-ground sources and
22、 receivers and for distances up to about 1 000 m. For high-energy impulsive sound sources, the impulsive sound event duration is short, and low frequencies are more prominent than for traffic and industrial sound sources. Lower-frequency sounds are generally less attenuated over a given distance in
23、the atmosphere than higher frequencies and, as a consequence, the level-influencing effects of propagation over much larger distances need to be taken into account. A general outline is given of a method that takes into account ground reflection, shielding by topography and the meteorological effect
24、s of refraction and turbulence. Starting from the source strength, this method calculates a distribution of immission levels for a set of replica atmospheres, each replica being a specific combination of atmospheric-absorption class and excess-attenuation class. To carry out practical calculations u
25、sing the procedure, it is useful to exploit the statistical contribution of the meteorological and ground surface conditions. In particular, histograms of the frequencies of occurrence of the wind velocity, wind direction, temperature, humidity and atmospheric stability can be used to describe the c
26、lasses. From the distribution of the immission levels, a number of assessment metrics can be obtained. For instance, the long-term averaged immission level can be calculated as a weighted average. The weighting factors are determined by the probability of occurrence of each replica atmosphere during
27、 the relevant time period for the location of interest. INTERNATIONAL STANDARD ISO 13474:2009(E) ISO 2009 All rights reserved 1Acoustics Framework for calculating a distribution of sound exposure levels for impulsive sound events for the purposes of environmental noise assessment 1 Scope This Intern
28、ational Standard specifies the framework of an engineering method for calculating a statistical distribution of sound exposure levels for impulsive sound events for the purposes of environmental noise assessment. This International Standard is applicable to impulse sounds propagating over large dist
29、ances (e.g. 0,5 km to 30 km) from sources such as mine blasting, artillery fire and bomb explosions, using conventional explosives of moderate charge mass (e.g. 0,05 kg to 1 000 kg of TNT equivalent). The effects of meteorological conditions and terrain upon sound propagation are considered. 2 Norma
30、tive references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 1996-1, Acoustics Description
31、, measurement and assessment of environmental noise Part 1: Basic quantities and assessment procedures ISO 3534-1, Statistics Vocabulary and symbols Part 1: General statistical terms and terms used in probability ISO 9613-1, Acoustics Attenuation of sound during propagation outdoors Part 1: Calculat
32、ion of the absorption of sound by the atmosphere ISO 9613-2, Acoustics Attenuation of sound during propagation outdoors Part 2: General method of calculation ISO 17201-1, Acoustics Noise from shooting ranges Part 1: Determination of muzzle blast by measurement ISO 17201-2, Acoustics Noise from shoot
33、ing ranges Part 2: Estimation of muzzle blast and projectile sound by calculation ISO 17201-4, Acoustics Noise from shooting ranges Part 4: Prediction of projectile sound ISO/IEC Guide 98-3, Uncertainty of measurement Part 3: Guide to the expression of uncertainty in measurement (GUM:1995) VDI MSR 8
34、/559, Standard Method to Measure the Sound Exposure Emissions and Immissions from Large Weapons (Standardmethode zur Messung der Geruschemissionen und -immissionen von schweren Waffen), Edmund Buchta (ed.), in Me-, Steuerungs- und Regelungstechnik, No. 8/559, Fortschritt-Berichte, VDI Verlag, Dsseld
35、orf, 1996 (in English and German) ISO 13474:2009(E) 2 ISO 2009 All rights reserved3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 atmospheric absorption attenuation of sound by air, resulting from viscous molecular processes, molecular rotati
36、on and molecular vibration 3.2 atmospheric-absorption class range of meteorological parameters yielding approximately the same attenuation of sound by air, all within a specified uncertainty NOTE See also atmospheric absorption. 3.3 atmospheric stability tendency of the atmosphere to reduce or enhan
37、ce vertical motion of the air NOTE Enhanced (or reduced) vertical motion of the air usually implies enhanced (or reduced) atmospheric turbulence. 3.4 atmospheric-stability class subset formed from partitioning the set of atmospheres according to stability NOTE See also atmospheric stability. 3.5 dir
38、ect path position displacement vector, in metres, originating at the source and describing a straight trajectory terminating at the receiver NOTE The direct path may intercept objects such as buildings or terrain. 3.6 directed sound speed algebraic sum of the adiabatic sound speed and the horizontal
39、 component of the wind velocity along the direct path NOTE Directed sound speed is expressed in metres per second. 3.7 directed sound speed profile sound speed along the direct path, expressed as a function of height NOTE See directed sound speed. 3.8 event single short burst, or rapid sequence of b
40、ursts, associated with a sound source NOTE A single activity, such as firing a gun, could produce multiple sound events. In the case of firing an explosive projectile from a high-velocity gun, sound events are associated with each of the following sound sources: the muzzle blast, the ballistic shock
41、 and the projectile impact. ISO 13474:2009(E) ISO 2009 All rights reserved 33.9 event duration T time interval starting just before immission, at time t 1 , and ending just after immission, at time t 2 , to encompass all significant sound of a single short blast or rapid sequence of blasts NOTE The
42、time interval t 2 t 1is expressed in seconds. 3.10 exceedance level sound level of a stated type, in decibels, exceeded by no more and no less than a stated percentage of samples NOTE The sampling set shall be identified, e.g. percentage of times during a stated time interval or percentage of firing
43、 events from an exercise. 3.11 excess attenuation that part of sound attenuation not included when accounting for geometric divergence (from a small sound source in non-refracting and non-moving air), atmospheric absorption of sound waves along the direct path from source to receiver and attenuation
44、 of screens and/or barriers NOTE Excess attenuation is expressed in decibels. 3.12 excess-attenuation class range of combined directed sound speed profiles and ground types yielding approximately the same attenuations, all within a specified uncertainty 3.13 ground condition sound reflection and abs
45、orption properties of outdoor surface(s) along the sound path(s) between source and receiver 3.14 impulsive sound event occurrence of a single short blast or series of blasts of sound in which the pressure-time history, close to the source, includes a rapid rise to the peak sound pressure followed b
46、y decay of the pressure 3.15 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 without modification to represent a root-mean-square sound pressure. However, roo
47、t-mean-square values should preferably be indicated by the subscript “eff”. ISO/TR 25417:2007, 2.1 3.16 open-air explosion blast, taking place out-of-doors, in which no part of the exploding material or gaseous products is limited by a container or any other obstructing surface ISO 13474:2009(E) 4 I
48、SO 2009 All rights reserved3.17 peak sound pressure p peakgreatest absolute sound pressure during a certain time interval NOTE 1 Peak sound pressure is expressed in pascals. NOTE 2 A peak sound pressure may arise from a positive or negative sound pressure. ISO/TR 25417:2007, 2.4 NOTE 3 This definiti
49、on is technically in accordance with ISO 10843. 3.18 peak sound pressure level L p, peakten times the logarithm to the base 10 of the ratio of the square of the peak sound pressure, p peak , to the square of a reference value, p 0 , expressed in decibels 2 peak ,peak 2 0 10 lg dB p p L p = where the reference value, p 0 , is 20 Pa NOTE Because of practical limitations of the measuring instruments, 2 peak p is always understood to denote the square of a frequency-weighted or frequency-band-limited pe
