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 entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising ther
2、efrom, is the sole responsibility of the user.” SAE reviews each technical report at least every five years at which time it may be revised, reaffirmed, stabilized, or cancelled. SAE invites your written comments and suggestions. Copyright 2015 SAE International All rights reserved. No part of this
3、publication may be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE. TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada) Tel: +1 724-776-49
4、70 (outside USA) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.org SAE values your input. To provide feedback on this Technical Report, please visit http:/www.sae.org/technical/standards/J2567_201511 SURFACE VEHICLE RECOMMENDED PRACTICE J2567 NOV2015 Issued 2004-01 R
5、eaffirmed 2009-01 Revised 2015-11 Superseding J2567 JAN2009 Measurement of Exhaust Sound Levels of Stationary Snowmobiles RATIONALE This revision is proposed to address issues observed while conducting sound pressure level measurements using the current document. Those issues were reported to commit
6、tee members by users of this document. In fact, snowmobile transmission calibrations have evolved over the years and because of different torque characteristics of newer engine designs, the snowmobile transmissions of a large number of models are fully engaged at 4000 rpm. This situation leads to th
7、e impossibility of conducting the test at 4000 rpm on those models without damaging the vehicle transmission component, especially the drive belt and drive pulley that are part of the CVT system. Tests were conducted by members of the committee and a new operating engine speed of 2500 rpm is propose
8、d in this revision. Some modifications are also proposed to the measurement section. Those modification are there for added clarity and are not intended to modify the measurement procedure. A minimum SPL limit is also included in this revision. The limit used to enforce noise levels by snowmobile tr
9、ail officers was 88 dB when performing the test at 4000 rpm. Tests conducted when decreasing operating engine speed from 4000 rpm to 2500 rpm showed an SPL decreasing by 5.3 dB on average. The SPL limit that is added to this document is 82 dB and was measured on very hard pack snow conditions typica
10、l of a snow covered parking lot in the winter. Therefore the ground condition section is also modifed to account for this ground condition. A similar SAE document (SAE J2825) includes minimum sound limits. 1. SCOPE This SAE Recommended Practice establishes the test procedure, environment and instrum
11、entation for determining the sound levels of snowmobiles in the stationary test mode. This test method is intended to provide an accurate measurement of exhaust and other engine noise and may be used to evaluate new and in-use snowmobiles to determine compliance with noise control regulations. Sound
12、 level measurements obtained with this test method are not intended as an engineering determination of overall machine noise. For this purpose, the use of SAE J192 is recommended. SAE INTERNATIONAL J2567 NOV2015 Page 2 of 4 2. REFERENCES 2.1 Applicable Documents The following publications form a par
13、t of this specification to the extent specified herein. Unless otherwise indicated, the latest issue of SAE publications shall apply. 2.1.1 SAE Publications Available from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or +1 724-776-49
14、70 (outside USA), www.sae.org. SAE J33 Snowmobile Definitions and Nomenclature - General SAE J192 Maximum Exterior Sound Level for Snowmobiles 2.1.2 ANSI Publications Copies of these documents are available online at http:/webstore.ansi.org/ ANSI S1.4 Specification for Sound Level Meters 2.2 Related
15、 Publication The following publications are provided for information purposes only and are not a required part of this SAE Technical Report. 2.2.1 SAE Publication Available from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or +1 724-
16、776-4970 (outside USA), www.sae.org. SAE J47 Maximum Sound Level Potential for Motorcycles SAE J2825 Measurement of Exhaust Sound Pressure Levels of Stationary On-Highway Motorcycles 3. DEFINITIONS 3.1 FIELD CALIBRATION Calibration of the sound level meter using an external sound level calibrator th
17、at will ensure the accuracy of the microphone and sound level meter. 3.2 INTERNAL CALIBRATION Calibration of the sound level meter by an internal oscillator or other means. The sound level meter internal calibration may be used, provided that the overall response of the sound level meter and microph
18、one are evaluated by an external acoustic calibrator meeting the requirements of 4.3, at the start and at the end of each test day. 3.3 LONGITUDINAL PLANE OF SYMMETRY The plane perpendicular to the horizon with the snowmobile sitting on a level surface which is parallel to the normal direction of tr
19、avel and equidistant between the skis. See SAE J33. SAE INTERNATIONAL J2567 NOV2015 Page 3 of 4 4. INSTRUMENTATION The following instrumentation shall be used: 4.1 A sound level meter that conforms to Type 1, Type S1A, Type 2 or Type S2A requirements of ANSI S1.4. 4.2 A microphone of the free-field
20、type. 4.3 A sound level calibrator with an accuracy of 0.2 dB. 4.4 A windscreen which does not affect microphone response more than 1.0 dB for the frequency range of 63 to 4000 Hz and 1.5 dB for frequencies ranging from 4000 to 10000 Hz. 4.5 An engine speed tachometer or other means of determining e
21、ngine speed with a steady-state accuracy of 3% at the prescribed test speed. 5. TEST SITE 5.1 The test site shall be a flat, open surface free of large sound-reflecting surfaces (other than the ground) such as parked vehicles, signboards, buildings or hillsides located within 5 m (16 ft) of the snow
22、mobile being tested and the location of the microphone. 5.2 The surface of the ground within the area described in 5.1 shall be grass or snow. Testing on a very hard packed snow condition is often unavoidable during enforcement test. Therefore this ground condition is considered and taken into accou
23、nt in the definition of the sound pressure limit discussed in section 9.1 6. PROCEDURE 6.1 The snowmobile shall be parked at the test site with an operator seated in the normal operating position, and the forward traveling path of the snowmobile clear of obstructions as required in 5.1. 6.2 The brak
24、e shall be set throughout the test. 6.3 The engine shall be started and run until reaching normal operating temperature range, as specified by the manufacturer. 6.4 The operator shall slowly open the throttle until a steady 2500 rpm 250 rpm engine speed is achieved, while holding the snowmobile stat
25、ionary by applying the brakes. 7. MEASUREMENTS 7.1 The sound level meter shall be set for A-weighting network and slow dynamic response. 7.2 The sound level meter shall be calibrated and adjusted, if necessary, so that the meter reads within 0.1 dB of the specified calibrator level at the microphone
26、. Record measured value. 7.3 The microphone shall be located on the side of the snowmobile towards which the exhaust outlet(s) is (are) directed. This is generally on the right side. The longitudinal axis of the microphone shall be parallel to the ground plane and perpendicular to the snowmobile lon
27、gitudinal plane of symmetry explained in section 3.3. There shall be no physical attachment between the snowmobile and the microphone/ sound level meter. 7.4 The microphone shall be located at a distance of 4.00 m / 157.5 in from the longitudinal plane of symmetry and 1.22 m / 48.0 in above the grou
28、nd plane in line with the exhaust outlet. If there is more than one exhaust outlet, it shall be located with reference to the centermost point of the multiple outlets. 7.5 It is recommended that no persons other than the snowmobile operator and the person performing the sound level measurements shal
29、l be within 3 m (10 ft) of the snowmobile or the microphone. If another observer is present, he shall remain in a fixed position behind the sound level meter so as to minimize his effect on the measurements. SAE INTERNATIONAL J2567 NOV2015 Page 4 of 4 7.6 With the snowmobile engine shut off, observe
30、 the overall ambient sound level at the measurement location. Record this level, including wind effects. In order for a test to be valid, the measured sound level of the snowmobile shall be at least 10 dB higher than the recorded ambient sound level. 7.7 Operate the snowmobile as specified in Sectio
31、n 6. Measure the sound level observed during steady-state operation at 2500 rpm 250 rpm over a period of not less than 4 seconds. Record the average reading. Immediately following the first test, repeat the test in an identical manner and record the reading. 7.8 For the test to be valid, the two rea
32、dings shall be within 2dB of one another. Report sound level as the average of the two readings. If the two readings are not within 2dB, repeat the test procedure of 7.7 until two readings within 2dB are obtained. 7.9 Repeat the ambient sound level measurement of 7.6. 7.10 Repeat the calibration pro
33、cedure of 7.2. Record measured value before performing any adjustment. If calibration has shifted more than 0.2 dB, the test shall be invalid. 8. GENERAL COMMENTS 8.1 It is essential that persons conducting the test be knowledgeable of the test procedure and use of the instrumentation. 8.2 Proper us
34、e of all test instruments is essential to obtain valid measurements. Operating manuals or other literature furnished by the instrument manufacturer should be referred to for both recommended operation of the instruments and precautions to be observed. 8.3 Specific Items for Consideration 8.3.1 The t
35、ype of microphone, its directional response characteristics, and its orientation relative to the source of sound. 8.3.2 The effects of ambient weather conditions on the performance of all instruments (that is, temperature, humidity and barometric pressure.) 8.3.3 Proper acoustical calibration proced
36、ures. 8.4 The use of the word “shall” in the procedure is to be understood as obligatory. The use of the word “should” is to be understood as advisory. The use of the word “may” is to be understood as permissive. 9. LIMIT 9.1 Any enforcement threshold based on this procedure shall not be numerically
37、 lower than 82 dBA, which is specified in direct relation to the test instrumentation, test site, procedure and measurement specified in the previous sections of this document. 10. NOTES 10.1 Revision Indicator A change bar (l) located in the left margin is for the convenience of the user in locatin
38、g areas where technical revisions, not editorial changes, have been made to the previous issue of this document. An (R) symbol to the left of the document title indicates a complete revision of the document, including technical revisions. Change bars and (R) are not used in original publications, nor in documents that contain editorial changes only. PREPARED BY THE SAE SNOWMOBILE TECHNICAL COMMITTEE
