1、SAE-J1074ADOPTION NOTICESAE-J1074, “ENGINE SOUND LEVEL MEASUREMENT PROCEDURE“, wasadopted on 14-DEC-92 for use by the Department of Defense(DoD). Proposed changes by DoD activities must be submitted tothe DoD Adopting Activity: Commander, US Army Missile Command,ATTN: AMSMI-RD-SE-TD-ST, Redstone Ars
2、enal, AL 35898-5270. Copies of this document may be purchased from the Society ofAutomotive Engineers 400 Commonwealth Drive Warrendale,Pennsylvania, United States, 15096-0001. http:/www.sae.org/_Custodians: Adopting Activity:Army - MIArmy - MINavy - ASAir Force - 11Reviewer Activities:Army - AR, AT
3、, MD, TE, TMAir Force - 19AREA HFACDISTRIBUTION STATEMENT A: Approved for public release; distributionis unlimited.Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-SAE Technical Standards Board Rules pr
4、ovide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirelyvoluntary, and its applicability and suitability for any particular use, including any patent infringement arising therefrom, is the sole responsibility of the u
5、ser.”SAE reviews each technical report at least every five years at which time it may be reaffirmed, revised, or cancelled. SAE invites your written comments and suggestions.TO PLACE A DOCUMENT ORDER: (724) 776-4970 FAX: (724) 776-0790SAE WEB ADDRESS http:/www.sae.orgCopyright 2000 Society of Automo
6、tive Engineers, Inc.All rights reserved. Printed in U.S.A.SURFACEVEHICLE400 Commonwealth Drive, Warrendale, PA 15096-0001RECOMMENDEDPRACTICESubmitted for recognition as an American National StandardJ1074REAF.FEB2000Issued 1974-07Reaffirmed 2000-02Superseding J1074 FEB87Engine Sound Level Measurement
7、 ProcedureForewordThis Reaffirmed Document has been changed only to reflect the new SAE Technical Standards BoardFormat. References were changed to Section 2. All other section numbers have changed accordingly.1. ScopeThis SAE Recommended Practice sets forth the equipment, environment, and test proc
8、edures to beused in measuring sound levels of engines. The purpose is to provide a uniform method of measuring themaximum acoustical radiation from the exterior surfaces of an engine under representative engine operatingconditions. The measured sound levels will be useful in development of engines,
9、comparison of engines, andinstallation of engines in various applications. The correlation of the measured engine sound levels to thevarious application sound levels will have to be developed.2. References2.1 Applicable PublicationsThe following publications form a part of the specification to the e
10、xtent specifiedherein. Unless otherwise indicated, the latest revision of SAE publications shall apply.2.1.1 SAE PUBLICATIONAvailable from SAE, 400 Commonwealth Drive, Warrendale, PA 15096-0001.SAE J184 FEB87Qualifying a Sound Data Acquisition System2.1.2 ANSI PUBLICATIONSAvailable from ANSI, 11 Wes
11、t 42nd Street, New York, NY 10036-8002.ANSI S1.4-1983 and S1.4A-1985Specification for Sound Level MetersANSI S1.11-1986Octave, Half-Octave, and Third-Octave Band Filter Sets2.1.3 OTHER PUBLICATIONLeo L. Beranek, “Noise and Vibration Control,” New York: McGraw-Hill Book Co., 1971, Chap. 9.Copyright S
12、AE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-SAE J1074 Reaffirmed FEB2000-2-3. Engine Classifications3.1 Bare EngineAn engine equipped with only the built-in accessories essential to its operation, such asflyw
13、heel, fuel pump, oil pump, water pump, and intake and exhaust manifolds. The sound from the exhaust,intake, flywheel housing opening, test stand, and dynamometer shall be minimized in order to measure thesound level of the basic or bare engine: although for aircooled engines where the cooling air fl
14、ows from theflywheel housing opening, the flywheel housing opening should not be covered. The exhaust and intakesounds shall be minimized by using remote mufflers and air cleaners, with heavy, acoustically treated piping tobare engine manifolds. Watercooled engines should not use a cooling fan. Isol
15、ation type engine mountsshould be used to minimize the vibrations to the engine test equipment.3.2 Fully Equipped EngineAn engine equipped with all mounted accessories necessary to perform its intendedfunction unaided. The accessories shall be specified and described. If the sound from the exhaust,
16、intake,and cooling systems are included, the systems should be specified and described. The sound from theflywheel housing opening, test stand, and dynamometer shall be minimized: although for aircooled engineswhere the cooling air flows from the flywheel housing opening, the flywheel housing openin
17、g should not becovered. The effect of the cooling fan airflow on the microphone should also be minimized (see 8.3).4. InstrumentationThe following instrumentation shall be used, where applicable, for the measurementrequired:4.1 A sound level meter which meets the Type 1 or S1A requirements of Americ
18、an National Standard Specificationfor Sound Level Meters, S1.4-1983 and S1.4A-1985.4.2 An octave band filter set which meets the Class II requirements of American National Standard Specificationsfor Octave, Half-Octave, and Third-Octave Band Filter Sets, S1.11-1986.4.3 As an alternative to making di
19、rect measurements using a sound level meter and octave band analyzer, amicrophone or sound level meter may be used with a magnetic tape recorder and/or a graphic level recorder orother indicating instrument, providing the system meets the requirements of SAE J184 FEB87, Qualifying aSound Data Acquis
20、ition System.4.4 An acoustic calibrator (see 8.4).4.5 An engine speed indicator, accurate to 1% or 10 rpm, whichever is greater.4.6 An anemometer (if outside tests are being performed).4.7 A windscreen may be used (see 8.3). The windscreen must not affect the microphone response more than1dB for the
21、 frequencies of 20 to 4000 Hz or 1-1/2 dB for frequencies of 4000 to 10 000 Hz.5. EnvironmentThe engine sound levels shall be measured in an environment such that results are equivalentto those obtained in a free field above a reflecting plane. Measurements may be made at a flat open space orin a ca
22、librated acoustically treated test cell.5.1 If a flat open space is used, it shall be free of the effect of large reflecting surfaces, such as signboards,buildings, or hillsides located within 30.4 m (100 ft) of either the engine or microphone. The surface within15.2m (50 ft) of either the engine or
23、 microphone shall be free from snow, grass, loose soil, or other acousticalabsorption materials. The area directly between the engine and the microphone shall be concrete, non-porousor sealed asphalt paving extending at least 3.0 m (10 ft) in all directions from the line between the engine andthe mi
24、crophone.Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-SAE J1074 Reaffirmed FEB2000-3-5.2 If an acoustically treated test cell is used, it must be calibrated for comparison to the flat open space for
25、 eachoctave band, A-weighted, and linear (or C-weighted) sound pressure level. The measurements from test cellsand outdoor test sites may not be directly comparable without a correction factor, because of a reverberantsound field contribution to the test cell measurements. The test cell correction f
26、actor and method ofdetermining the correction factor should be reported with the measured engine sound levels (see 2.1.3).5.3 The ambient sound pressure levels (including wind effects) coming from sources other than the engine beingmeasured shall be at least 10 dB below the level of the tested engin
27、e.5.4 Because bystanders have an appreciable influence on meter response when they are in the vicinity of theengine or microphone, not more than one person, other than the observer reading the meter, shall be present,and that person shall be directly behind the observer reading the meter, on a line
28、through the microphone andthe observer. If the meter operator or engine/dynamometer operator are in the test cell, they should be to therear of the engine or at the maximum allowable distance from the engine or microphones.6. Measurements6.1 The microphone shall be located 1.0 m (3.3 ft) from the lo
29、ngitudinal centers of the vertical planes forming thesmallest rectangle which completely encloses the bare engine. Measurements shall be made on both sidesand in front of the engine at the height of the exhaust manifold, but not less than 1.0 m (3.3 ft) above the floor.A survey of the A-weighted sou
30、nd level shall be made at this microphone height and distance from therectangular box. If the survey indicates a reading(s) more than 3 dB above the highest reading at the threespecified locations, the sound level at this location(s) shall be also reported. The microphone positions thusreferred to t
31、he bare engine shall be used for tests on fully equipped engines.6.1.1 If the flat open space is used for optional correlation with most of the SAE sound level measurements ofvehicles, additional sound measurements may be made with the microphone located at a height of 1.2 m(4ft) above the surface a
32、nd at 15.2 m (50 ft) from the center of the engine.6.1.2 If the flat open space is used for optional correlation with most ISO sound level measurements, additionalsound measurements may be made with the microphone located at a height of 1.2 m (4 ft) and 7.5 m (25 ft)from the center of the engine or
33、7.0 m (23 ft) from major surfaces.6.2 The sound level meter or other indicating instrument shall be set for slow response. At each of the microphonelocations, the following measurements shall be made:a. The sound level using the A-weighting network.b. The sound pressure level using the linear or C-w
34、eighting network; the network used shall be reported.c. The octave band sound pressure levels for center frequencies of 63 to 8000 Hz at the microphonelocation having the highest A-weighted sound level, as determined in 6.1.d. The reported data shall be identified as to the microphone location.The r
35、eported sound pressure level shall be the average of two or more readings that are within 2 dB of eachother.7. Engine OperationThe engine shall be previously checked for rated performance and proper tune-up andshall be operated at the following steady conditions after reaching normal operating condi
36、tions:a. Rated speed and load.b. For governed engines, maximum governed speed at no load; for ungoverned engines, rated speed atno load.c. Speed and load resulting in peak torque.d. Recommended low idle speed.Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduc
37、tion or networking permitted without license from IHS-,-SAE J1074 Reaffirmed FEB2000-4-8. General Comments8.1 It is essential that technically trained personnel select the equipment and that the tests be conducted only bypersons trained in the current techniques of sound measurement.8.2 Instrument m
38、anufacturers specifications for orientation of the microphone relative to the source of sound andthe location of the observer relative to the meter should be followed. The microphone or sound level metertemperatures should be monitored to prevent overheating from the exhaust manifold.8.3 It is recom
39、mended that measurements be made only when wind speed is below 19 km/h (12 mph). Themicrophone windscreen may be used to minimize the effects of wind gusts and other changes in wind velocity.8.4 Instrument manufacturers recommended calibration should be made at appropriate times. Field calibrationss
40、hould be made immediately before and after each test sequence. Either an external calibration or internalcalibration means is acceptable for field use, provided that external calibration is accomplished before or afterthe field test.8.5 If a tape recorder is used, record a calibration tone of a know
41、n sound pressure level on the tape, using thesame microphone and the same recorder attenuation settings immediately before and after the series ofrecordings.8.6 The sound level of a diesel engine may be dependent on the fuels cetane level. A diesel fuel with a cetanenumber between 42 and 50 is recom
42、mended. For gasoline-fueled engines, a fuel grade consistent with theengine manufacturers recommendations should be used.PREPARED BY THE SAE VEHICLE SOUND LEVEL COMMITTEECopyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without li
43、cense from IHS-,-SAE J1074 Reaffirmed FEB2000RationaleNot applicable.Relationship of SAE Standard to ISO StandardNot applicable.ApplicationThis SAE Recommended Practice sets forth the equipment, environment, and test proceduresto be used in measuring sound levels of engines. The purpose is to provid
44、e a uniform method ofmeasuring the maximum acoustical radiation from the exterior surfaces of an engine underrepresentative engine operating conditions. The measured sound levels will be useful in development ofengines, comparison of engines, and installation of engines in various applications. The
45、correlation ofthe measured engine sound levels to the various application sound levels will have to be developed.Reference SectionSAE J184 FEB87Qualifying a Sound Data Acquisition SystemANSI S1.4-1983 and S1.4A-1985Specification for Sound Level MetersANSI S1.11-1986Octave, Half-Octave, and Third-Oct
46、ave Band Filter SetsLeo L. Beranek, “Noise and Vibration Control,” New York: McGraw-Hill Book Co., 1971, Chap. 9.Developed by the SAE Vehicle Sound Level CommitteeCopyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-
