SAE J 1477-1986 Measurement of Interior Sound Levels of Light Vehicles.pdf

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1、SAE Technical Standards Board Rules provide 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 therefro

2、m, is the sole responsibility of the user.”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.s

3、ae.orgCopyright 2000 Society of Automotive Engineers, Inc.All rights reserved. Printed in U.S.A.SURFACEVEHICLE400 Commonwealth Drive, Warrendale, PA 15096-0001RECOMMENDEDPRACTICESubmitted for recognition as an American National StandardJ1477REAF.MAY2000Issued 1986-01Reaffirmed 2000-05Superseding J14

4、77 JAN1986Measurement of Interior Sound Levels of Light VehiclesForewordThis Document has not changed other than to put it into the new SAE Technical Standards BoardFormat. References were added as Section 2. All other section numbers changed accordingly.1. ScopeThis SAE Recommended Practice establi

5、shes the test procedure, environment, instrumentation, anddata analyses for comparing interior sound level of passenger cars, multipurpose vehicles, and light truckshaving gross vehicle weight rating (GVWR) of 4540 kg (10 000 lb) or less.The test procedure is characterized by having fixed initial co

6、nditions (specified initial vehicle speed and gearselection at the starting point on the test site) to obtain vehicle interior sound measurement during road loadoperation over various road surfaces at specified constant speeds.The measurement data so derived is useful for vehicle engineering develop

7、ment and analysis.1.1 OperationPerform a standard series of tests at 60, 70, 80, 90, and 100 km/h (38, 44, 50, 56, 63 mph) onsmooth (within normal construction practice) level asphalt or equivalent road surface.Perform special tests at desired speeds on designated road surfaces, and/or with special

8、noise producingsystems operating, as desired.2. References2.1 Applicable PublicationsThe following publications form a part of the specification to the extent specifiedherein. Unless otherwise indicated, the latest revision of SAE publications shall apply.2.1.1 SAE PUBLICATIONAvailable from SAE, 400

9、 Commonwealth Drive, Warrendale, PA 15096-0001.SAE J184Qualifying a Sound Data Acquisition System2.1.2 ANSI AND ISO PUBLICATIONSAvailable from ANSI, 11 West 42nd Street, New York, NY 10036-8002.ANSI S1.4American National Standard Specification for Sound Level metersISO 5128Acoustics, measurement of

10、noise inside motor vehiclesSAE J1477 Reaffirmed MAY2000-2-2.2 Related PublicationsThe following publications are provided for information purposes only and are not arequired part of this document.2.2.1 SAE PUBLICATIONAvailable from SAE, 400 Commonweatlh Drive, Warrendale, PA 15096-0001.SAE J986Sound

11、 Level for Passenger Cars and Light Trucks2.2.2 OTHER PUBLICATIONSAvailable from McGraw-Hill Book Company, New York.Beranek, Leo L., Noise and Vibration Control, p. 554, 1971.3. InstrumentationThe following instrumentation shall be used:3.1 Two sound level meters which meet the type 1 or S1A require

12、ments of the American National StandardSpecifications for Sound Level Meters, S1.4.3.2 Two condenser type omni-directional microphones.3.3 A two-channel audio tape recorder (if analyses described in 8.2 are to be obtained) conforming to therequirements of SAE Recommended Practice J184a, Qualifying a

13、 Sound Data Acquisition System.3.4 A sound level calibrator accurate to 0.5 dB.3.5 An anemometer accurate to 10% at 18 km/h (11 mph).3.6 Instrumentation to measure the vehicle speed accurate to 2% for a desired test condition.4. Test Site4.1 The test site shall be a flat open space free of large ref

14、lecting surfaces which affect the sound level. Nopassing vehicles may be in the vicinity of the test vehicle while measurements are being made.4.2 The test site shall include a vehicle path of sufficient length for safe acceleration, deceleration, and stopping ofthe vehicle.4.3 The test road surface

15、s shall be hard, as smooth and level as possible, and of uniform surface texture1. Thetest road surfaces shall be in good repair and free of local extraneous material such as sand, gravel, snow,water, leaves, etc.5. Vehicle PreparationThe test vehicle shall be properly prepared for the test.5.1 Duri

16、ng the test, all operating conditions of the engine shall correspond to the specifications provided by themanufacturer, for example, fuel, lubricating oil, temperature, and ignition timing.5.2 The tires shall be of a type specified by the vehicle manufacturer as being appropriate to the conditions u

17、nderwhich the vehicle is normally used. The cold tire pressure shall be as recommended by the vehiclemanufacturer.5.3 Exhaust system, suspension, and steering including front end alignment and wheel(s) balance shall bechecked and corrected as required to conform to the manufacturers specifications.1

18、. It should be noted that road surface texture differences may produce variability in test results.SAE J1477 Reaffirmed MAY2000-3-5.4 All the windows and ventilating systems shall be tightly closed. Accessories such as windshield wipers andselectable ventilating fans shall not be operated for the st

19、andard test. Special tests, such as with an air-conditioning unit operating at higher blower speed, may be specified. Any system which operatesautomatically and affects the sound level reading must be identified in the test report, preferably with data forthe different operating modes.5.5 Operate th

20、e test vehicle for 8 km (5 mile) at 90 km/h (55 mph) to warm up the engine and tires immediatelybefore the test.6. Microphone PositionsThe noise inside a vehicle may vary considerably with location. Therefore,measuring points should be selected in sufficient number and in such a manner that the dist

21、ribution of thenoise in the vehicle is adequately represented with respect to driver and passenger locations.One measuring point shall be at the drivers position.The microphone shall be no closer than 0.15 m (6 in) from walls or upholstery.The microphone shall be oriented so that the direction of th

22、e manufacturers recommended free fieldorientation is the same as the direction in which a person occupying the seat would be looking, or if suchdirection is not defined, in the driving direction. If a different orientation is used, it shall be reported.The microphone used during the tests shall be m

23、ounted in such a way that it is not affected by vibrations of thevehicle. The mounting shall prevent excessive (more than about 20 mm) amplitudes relative to the vehicle.6.1 Microphone position with respect to a seat (see Figure 1).FIGURE 1MICROPHONE POSITION WITH RESPECT TO A SEAT.The vertical coor

24、dinate of the microphone shall be 0.7 m 0.05 m (28 in 2 in) above the intersection of theunoccupied seat surface and the surface of the back of the seat (see Figure 1). The horizontal coordinate shallbe the middle plane (or plane of symmetry) of the unoccupied seat. At the drivers seat, with the dri

25、ver present,the horizontal coordinate shall be 0.2 m 0.02 m (8 in 1 in) to the right from the middle plane of the seat.Adjustable seats shall be set in the mid position of the horizontal and vertical range of adjustment. If the backrest of the seat is adjustable, it shall be set as near to the verti

26、cal position as possible.Adjustable head rests shall be set at the mid position.SAE J1477 Reaffirmed MAY2000-4-7. Measurements7.1 The sound level meters shall be set for the fast dynamic response and for the A-weighting network.7.2 Observe the sound level meter or indicating instrument while the veh

27、icle is proceeding at each constant speedfor at least 30 s. Where a sound level meter only is used, the applicable reading shall be the average soundlevel observed during the run.7.3 If a tape recorder is used as part of the measuring equipment, it may be necessary to include suitable pre-emphasis a

28、nd de-emphasis networks for recording and reproduction to provide an adequate signal-to-noiseratio over the whole frequency range of interest. For analysis of the data, refer to 8.2.7.4 For all measurements of A-weighted sound pressure levels, the lower limit of the dynamic range set by thebackgroun

29、d noise2and by the inherent noise level of the measuring equipment shall be at least 10 dB belowthe A-weighted sound pressure levels of the vehicle noise.7.5 The ambient air temperature, in which the vehicle is operating, shall be in the range 5 C to +35 C (23 F to95 F). The wind speed along the tes

30、t track measured at a height of approximately 1.2 m (47 in) shall notexceed 18 km/h (11 mph). The other meteorological conditions shall be such that they do not influence themeasurements. The ambient temperature, speed of the wind, and the direction of the wind relative to the testtrack shall be sta

31、ted.7.6 Repeat 7.1, 7.2, 7.3, 7.4, and 7.5 for special road surface or system operation as desired by engineeringdevelopment requirements.8. Analyses8.1 Interior sound levels, expressed in dBA at specified vehicle speeds for a given road surface, are widelyaccepted for evaluating vehicle interior no

32、ise.8.2 When a tape recorder is used during measurements and a one-third octave frequency analyzer is used toobtain the frequency spectrum, the following parameters may be obtained:8.2.1 Overall average “A” weighted sound level;8.2.2 Overall average unweighted sound level;8.2.3 Total Stevens Mark VI

33、I sones;8.2.4 Perceived “phons”;8.2.5 Preferred octave band speech interference level;8.2.6 Total percent speech intelligibility;8.2.7 Composite rating of preference.2. Defined as the interior sound level at the desired microphone location in the stationary vehicle with engine off.SAE J1477 Reaffirm

34、ed MAY2000-5-9. General Comments9.1 Technically competent personnel should select equipment, and tests should be conducted only by qualifiedpersons familiar with the current technique of sound measurements.9.2 While making sound level measurements, only the driver and instrumentation operator shall

35、be in the vehicle.9.3 Proper use of all test instrumentation is essential to obtain valid measurements. Operating manuals or otherliterature furnished by the instrument manufacturer should be referred to for both recommended operation ofthe instrument and precautions to be observed. Specific items t

36、o be considered are:9.3.1 Proper signal levels, terminating impedances, and cable lengths on multi-instrument measurement systems.9.3.2 Proper acoustical calibration procedure, to include the influence of extension cables, etc. Field calibrationshall be made immediately before and after each test se

37、quence. Internal calibration means is acceptable forfield use, provided the external calibration is accomplished immediately before and after field use.9.4 Vehicles used for tests shall not be operated in a manner such that the break-in procedure specified by themanufacturer is violated.9.5 It shoul

38、d be recognized that variations in measured sound levels may occur due to variations in test site,ambient weather differences (temperature, wind, and their gradients), test equipment differences, and inherentdifferences between nominally identical vehicles, for example, squeaks, rattles, etc.9.6 It

39、is important to note that the test procedure is particularly written for the measurement of interior sound levelsof light vehicles, while ISO Standard 5128 is a generalized interior noise test procedure.PREPARED BY THE SAE MOTOR VEHICLE COUNCIL SOUND LEVEL COMMITTEESAE J1477 Reaffirmed MAY2000Ration

40、aleNot applicable.Relationship of SAE Standard to ISO StandardIt is important to note that the test procedure is particularlywritten for the measurement of interior sound levels of light vehicles, while ISO Standard 5128 is ageneralized interior noise test procedure.ApplicationThis SAE Recommended P

41、ractice establishes the test procedure, environment, instrumentationand data analyses for comparing interior sound level for passenger cars, multipurpose vehicles, and lighttrucks having gross vehicle weight rating (GVWR) or 4540 kg (10 000 lb) or less.The test procedure is characterized by having f

42、ixed initial conditions (specified initial vehicle speed andgear selection at the starting point on the test site) to obtain vehicle interior sound measurement duringroad load operation over various road surfaces at specified constant speeds.The measurement data so derived is useful for vehicle engi

43、neering development and analysis.Reference SectionISO Standard 5128Acoustics, Measurement of Noise Inside Motor VehiclesSAE J184Qualifying a Sound Data Acquisition SystemSAE J986bSound Level for Passenger Cars and Light TrucksAmerican National Standard Specification for Sound Level Meters; S1.4Beranek, Leo L., Noise and Vibration Control, p. 554, McGraw-Hill Book Company, New York, 1971Developed by the SAE Motor Vehicle Council Sound Level Committee