SAE J331:2020 pdf download

SAE J331:2020 pdf download Sound Levels for Motorcycles
2.REFERENCES
2.1 Applicable Documents
The following publications form a part of this specification to the extent specified herein. Unless otherwise indicated, thelatest issue of SAE publications shall apply.
2.1.1 SAE Publications
Available from SAE International, 400 Commonwealth Drive,Warrendale, PA 15096-0001,Tel: 8T7-606-7323 (insideUSA and Canada) or 724-776-4970(outside USA), www.sae.org.
SAE J47
Maximum Sound Level Potential for Motorcycles
SAE J184
Qualifying a Sound Data Acquisition System
SAE J213
Motorcycle Classifications
SAE J1349 Engine Power Test Code -Spark Ignition and Compression kgnition – As Installed Net Power Rating
2.1.2ANSI Publication
Available from American Nafional Standards Institute, 25 West 43rd Street, New York,NY10036-8002,Tel: 212-642-4900,www.ansi.org.
ANSI S1.4-1983Specification for Sound Level Meters3.DEFINITIONS
3.1 MANUAL TRANSMISSION
A transmission having multiple discrete gear ratios which are individually selectable by the vehicle operator.
3.2AUTOMATIC TRANSMISSION
A transmission which does not have multple discrete gear ratios individually selectable by the vehicle operator.
3.3 RATED ENGINE SPEED
The engine speed in revolutions per minute at which the engine delivers its maximum net brake power as defined in SAEJ1349 as determined by the manufacturer.
3.4LONGITUDINAL PLANE OF SYMMETRY
As defined in SAE J213.
4.INSTRUMENTATION
4.1 The following instrumentation shall be used where applicable:
4.1.1 A sound level meter which meets the Type 1 or Type S1A requirements of ANSI S1.4-1983. As an alternative to making direct measurements using a sound level meter, a microphone or sound level meter may be used withrecorder or other indicating instrument, provided that the system meets the requirements of SAE J184.
4.1.2 A sound level calibrator with an accuracy of +0.5dB dB conforming to IEC942(1988) Class 1 andJor ANSI S1.40-1984 (see 9.6.4).
4.1.3 An engine speed tachometer, or other means of determining engine speed, with a steady-state accuracy of ±3%at 60% and 100% of rated engine speed.
4.1.4 A speedometer with steady-state accuracy of 13% at a vehice speed of 50 km/h (31 mph).4.1.5 An anemometer with steady-state accuracy of ±10% at a wind speed of 5.5 mls (12 mph).
4.1.6 An acceptable wndscreen may be used with the microphone. To be acceptable, the screen shall not affect the
microphone response more than +1 dB for frequencies of 63 to 4000 Hz and 土1.5 dB for frequencies of 4000 to10000 Hz, taking into account the orientation of the microphone.
5. TEST SITE
5.1 The test site (Figure 1) shall be a flat open space accommodating a straight vehicle path and the following points:On the vehicle path-
a. The microphone target point
b. Acceleration point – a point 7.5 m (25 ft) prior to the microphone target pointc. End point – a point 30 m(100) beyond the microphone target point
d. A point 15 m (50 ft) prior to the microphone target point
e. A point 15 m (50 ft) beyond the microphone target point Off the vehicle path-
f. Microphone point – a point 15 m (50 ft) from the vehicle path on the perpendicular line which passes through themicrophone target point
g.Measurement area