ISO 15619-2013 Reciprocating internal combustion engines - Measurement method for exhaust silencers - Sound power level of exhaust noise and insertion loss usin.pdf

1、 ISO 2013 Reciprocating internal combustion engines Measurement method for exhaust silencers Sound power level of exhaust noise and insertion loss using sound pressure and power loss ratio Moteurs alternatifs combustion interne Mthode de mesure pour silencieux dchappement Niveau de puissance acousti

2、que du bruit lchappement et perte par insertion partir de la pression acoustique et du rapport de perte de puissance INTERNATIONAL STANDARD ISO 15619 First edition 2013-10-01 Reference number ISO 15619:2013(E) ISO 15619:2013(E)ii ISO 2013 All rights reserved COPYRIGHT PROTECTED DOCUMENT ISO 2013 All

3、 rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested fr

4、om either ISO at the address below or ISOs member body in the country of the requester. 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 ISO 15619:2013(E) ISO 2013 All rights reserved

5、iii Contents Page Foreword iv Introduction v 1 Scope . 1 1.1 Measurement uncertainty . 1 2 Normative references 2 3 T erms and definitions . 2 4 Test environment . 6 4.1 General . 6 4.2 Criteria for background noise 7 4.3 Criterion for acoustic adequacy of test environment 9 5 Instrumentation .10 5.

6、1 General 10 5.2 Calibration .10 6 Installation and operation of noise source under test for laboratory measurement10 6.1 General 10 6.2 Source location .11 6.3 Installation requirements .11 6.4 Operation condition .13 7 Measurement 13 7.1 General 13 7.2 Laboratory measurement .14 7.3 Site measureme

7、nt 17 8 Calculation .20 8.1 General 20 8.2 Calculation of sound power level of exhaust noise .20 8.3 Calculation of insertion loss .22 8.4 Calculation of power loss ratio .23 9 Information to be recorded 23 9.1 General 23 9.2 Description of the tested exhaust silencer and substitution pipe .23 9.3 D

8、escription of the engine on which the exhaust silencer is installed .23 9.4 Acoustic environment 23 9.5 Description of instrumentation .23 9.6 Acoustical data .23 10 Test report 24 Annex A (normative) Qualification pr oc edur es for the ac oustic en vir onment .25 Annex B (informative) Measurement p

9、rocedure for pressure loss30 Annex C (normative) Calculation of A-weighted sound power levels from frequency band levels 31 Annex D (normative) Sound power level under reference meteorological conditions 33 Bibliography .35 ISO 15619:2013(E) Foreword ISO (the International Organization for Standardi

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16、TC 70, Internal combustion engines.iv ISO 2013 All rights reserved ISO 15619:2013(E) Introduction This International Standard specifies methods for measuring the sound power level of exhaust noise and the insertion loss of exhaust silencers installed on reciprocating internal combustion engines and

17、a method for measuring the power loss ratio of reciprocating internal combustion engines. Sound power level of exhaust noise, insertion loss, and transmission loss are parameters to characterize the acoustic performance of exhaust silencers. Sound power levels of exhaust noise and insertion loss are

18、 important parameters to characterize the acoustic matching performance of exhaust silencers and reciprocating internal combustion engines. Transmission loss is the difference in sound power level of exhaust noise between the noise before and after transmitting through the exhaust silencer, which is

19、 the parameter to characterize the acoustic performance of the exhaust silencer itself and is irrelevant with the reciprocating internal combustion engine. Power loss ratio and pressure loss are parameters to characterize the aerodynamic performance of exhaust silencers. Power loss ratio is an impor

20、tant parameter to characterize the aerodynamic matching performance of exhaust silencers and reciprocating internal combustion engines, whereas resistance coefficient which is closely related to pressure loss is to characterize the aerodynamic performance of the exhaust silencer itself and is irrele

21、vant with the reciprocating internal combustion engine on which the exhaust silencer is installed. The matching parameters of the sound power level of exhaust noise, the insertion loss, and the power loss ratio are used in this International Standard as the measurement parameters. For sound power le

22、vel of exhaust noise, the measurement results at 90 direction and 45 direction can be different. The measurement results at 45 direction is slightly greater than the actual value, the measurement results at 90 direction is much closer to the actual results. For insertion loss, the measurement result

23、s at 90 direction and 45 direction may be different, but the measurement uncertainty at 90 direction is smaller than that at 45 direction. Measurement at 90 direction is used for the laboratory measurement (engineering method). The measurement at 90 or 45 direction is used for laboratory measurement

24、 (survey method). The measurement at 45 direction is used for site measurement. ISO 2013 All rights reserved v Reciprocating internal combustion engines Measurement method for exhaust silencers Sound power level of exhaust noise and insertion loss using sound pressure and power loss ratio 1 Scope Th

25、is International Standard specifies the measurement method and requirements for exhaust silencers which is installed on reciprocating internal combustion engines, including laboratory measurement and site measurement. The following parameters are measured for laboratory measurement (engineering meth

26、od): the sound power level (A-weighted or in frequency bands) of exhaust noise using sound pressure, accuracy grade 2; the insertion loss (A-weighted or in frequency bands) of exhaust silencers; the power loss ratio of reciprocating internal combustion engines. The following parameters are measured

27、for site measurement and laboratory measurement (survey method): the sound power level (A-weighted) of exhaust noise using sound pressure, accuracy grade 3; the insertion loss (A-weighted) of exhaust silencers. NOTE 1 The aim of laboratory measurement in measuring the sound power level of exhaust no

28、ise is accuracy grade 2 (engineering method) result. When the correction for background noise and/or the environment conditions and/or the location of exhaust outlets cannot meet the requirements of the engineering method of this International Standard, then accuracy grade 3 (survey method) result i

29、s obtained. The aim of site measurement in measuring the sound power level of exhaust noise in this International Standard is accuracy grade 3 (survey method) result. The laboratory measurement (engineering method) of this International Standard can be used to make acceptance tests and engineering m

30、easures. The site measurement and laboratory measurement (survey method) of this International Standard can be used to make comparative tests. This International Standard applies to all exhaust silencers installed on reciprocating internal combustion engines falling within the field of application o

31、f ISO 3046-1 and other exhaust silencers, if no suitable International Standard exists. NOTE 2 Throughout the text, exhaust silencer is referred to as silencer and reciprocating internal combustion engine as engine. 1.1 Measurement uncertainty 1.1.1 Engineering method The standard deviation of repro

32、ducibility is equal to or less than 1,5 dB for A-weighted sound power levels. In one-third octave bands, it is equal to or less than 5 dB from 50 Hz to 80 Hz, 3 dB from 100 Hz to 160 Hz, 2 dB from 200 Hz to 315 Hz, 1,5 dB from 400 Hz to 5 000 Hz, and 2,5 dB from 6 300 Hz to 10 000 Hz. In octave band

33、s, it is equal to or less than 5 dB for 63 Hz, 3 dB for 125 Hz, 2 dB for 250 Hz, 1,5 dB from 500 Hz to 4 000 Hz, and 2,5 dB for 8 000 Hz. INTERNATIONAL ST ANDARD ISO 15619:2013(E) ISO 2013 All rights reserved 1 ISO 15619:2013(E) 1.1.2 Survey method The standard deviation of reproducibility is equal

34、to or less than 4,0 dB for A-weighted sound power levels. NOTE 1 The standard deviations listed in 1.1 are associated with the test conditions and procedures defined in this International Standard and not with the noise source itself, including variations of installation and/or operation conditions.

35、 They arise in part from variations between measurement laboratories, changes in atmospheric conditions if outdoors, the geometry of the test room or outdoor environment, the acoustical properties of the reflecting plane, absorption at the test room boundaries if indoors, background noise, and the t

36、ype and calibration of instrumentation. They are also due to variations in experimental techniques, including the size and shape of the measurement surface, measurement distances, number and location of microphone positions, sound source location, determination of environmental corrections, if any,

37、and integration time. The standard deviations are also affected by errors associated with measurements taken in the near field of the source. Such errors depend upon the nature of the sound source, but generally increase for smaller measurement distances and lower frequencies (below 250 Hz). NOTE 2

38、If several laboratories use similar facilities and instrumentation, the results of sound power determinations on a given source in those laboratories may be in better agreement than would be implied by the standard deviations of 1.1. NOTE 3 For a family of silencers, of similar size with similar sou

39、nd power spectra and similar operating conditions, the standard deviations of reproducibility may be smaller than the values given in 1.1. NOTE 4 The standard deviations of reproducibility, as listed in 1.1, include the uncertainty associated with repeated measurements on the same noise source under

40、 the same conditions (for standard deviations of reproducibility). This uncertainty is usually much smaller than the uncertainty associated with interlaboratory variability. NOTE 5 The procedures of this International Standard and the standard deviations given in 1.1 are applicable to measurements o

41、n an individual silencer. The measurement uncertainty depends on the standard deviation of reproducibility and on the degree of confidence that is desired. As examples, for a normal distribution of sound power levels, there is 90 % confidence that the true value of the sound power level of a source

42、lies within the range 1,645 Rof the measured value and a 95 % confidence that it lies within the range 1,960 Rof the measured value. NOTE 6 For a normal distribution of sound power levels, there is 90 % confidence that the probability of acceptance is 95 % and a 95 % confidence that the probability

43、of acceptance is 97,5 %. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced docu

44、ment (including any amendments) applies. ISO 3046-1:2002, Reciprocating internal combustion engines Performance Part 1: Declarations of power, fuel and lubricating oil consumptions, and test methods Additional requirements for engines for general use ISO 3046-3:2006, Reciprocating internal combustio

45、n engines Performance Part 3: Test measurements ISO 6926:1999, Acoustics Requirements for the performance and calibration of reference sound sources used for the determination of sound power levels IEC 60942:2003, Electroacoustics Sound calibrators IEC 61260:1995, Electroacoustics Octave-band and fr

46、actional-octave-band filters IEC 61672-1:2002, Electroacoustics Sound level meters Part 1: Specifications 3 T erms a nd definiti ons For the purposes of this document, the following terms and definitions apply.2 ISO 2013 All rights reserved ISO 15619:2013(E) 3.1 sound pressure p difference between i

47、nstantaneous pressure and static pressure, expressed in pascals 3.2 sound pressure level L p ten times the logarithm to the base 10 of the ratio of the square of the sound pressure, p, to the square of a reference value, p 0 where the reference value, p 0 , is 20 Pa Note 1 to entry: If specific freq

48、uency and time weightings, as specified in IEC 616721, and/or specific frequency bands are applied, this is indicated by appropriate subscripts, e.g. L pAdenotes the A-weighted sound pressure level. Note 2 to entry: It is expressed in decibels. 3.3 time-averaged sound pressure level L p,T ten times

49、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 t 1and ending at t 2 ), to the square of a reference value, p 0 where the reference value, p 0 , is 20 Pa Note 1 to entry: In general, the subscript “T” is omitted since time-averaged sound pressure levels are necessarily determined over a certain