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 there
2、from, 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 2012 SAE International All rights reserved. No part of this p
3、ublication 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: +1 724-776-497
4、0 (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/J2825_201211SURFACE VEHICLE RECOMMENDED PRACTICE J2825 NOV2012 Issued 2009-05 Rev
5、ised 2012-11 Superseding J2825 MAY2009 Measurement of Exhaust Sound Pressure Levels of Stationary On-Highway Motorcycles RATIONALE This document was revised to allow the use of sound level meters and calibrators conforming to specified earlier ANSI standards. FOREWORD This recommended practice estab
6、lishes an alternative to SAE J1287 for measuring exhaust sound pressure levels of stationary motorcycles. Users of SAE J1287 for roadside enforcement of sound pressure levels for on-highway motorcycles have reported difficulties with its implementation and this document seeks to address those concer
7、ns by simplifying the test procedures and conditions. Both an Idle Test and a Set RPM Test are defined. The Idle Test can be used independently to identify some vehicles with excessively loud exhaust systems. However, the Set RPM Test will be more effective and should be used instead of the Idle Tes
8、t when the objective is maximizing the identification of vehicles that substantially exceed Federal EPA standards. A non-constant, Swept RPM Test Method is also included as an alternative to the Set RPM Test for motorcycles that will not hold constant rpm under a no-load condition. The test procedur
9、es described in Section 7 and the exhaust sound pressure level (dBA) limits specified in Section 9 are based on a comprehensive study of a wide variety of on-highway motorcycles tested with both original equipment and aftermarket exhaust systems. The specified limits were determined through an exten
10、sive investigation of correlation between measurement results obtained using the Federal EPA passby procedure (Appendix I to Subparts D and E of the-Motorcycle Noise Emission Test Procedures in Title 40, Code of Federal Regulations CFR, Part 205 ) with results obtained using the stationary procedure
11、s described in this document, and have been set so as not to fail vehicles that comply with the Federal EPA requirements specified in 40 CFR Part 205. To avoid false failures of vehicles certified to meet the Federal EPA standards, any standards set based on this procedure shall not be numerically l
12、ower than the exhaust sound pressure level (dBA) limits specified in Section 9. Care must be taken not to confuse stationary sound pressure levels with total motorcycle sound pressure levels. The procedures of this document do not evaluate total motorcycle sound during operation. For that purpose, S
13、AE J331 or SAE J47 is recommended. SAE J2825 Revised NOV2012 Page 2 of 11 1. SCOPE This SAE Recommended Practice establishes test procedures, test conditions, environment, and instrumentation for determining the exhaust sound pressure levels of stationary motorcycles. These are based on a comprehens
14、ive study of a wide variety of on-highway motorcycles, and therefore are intended to be applied to on-highway motorcycles. For off-highway motorcycles, SAE J1287 continues to be the recommended practice. 1.1 Purpose This document is intended to provide a basis for roadside monitoring or screening of
15、 stationary on-highway motorcycle exhaust sound pressure levels where use of a more comprehensive procedure for measuring total motorcycle sound during operation, such as SAE J331 or SAE J47, is not practical. 2. REFERENCES 2.1 Applicable Documents The following publications form a part of this spec
16、ification 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 724-776-4970 (outside USA),
17、 www.sae.org. SAE J47 Maximum Sound Level Potential for Motorcycles SAE J184 Qualifying a Sound Data Acquisition System SAE J213 Motorcycle Classifications SAE J331 Sound Levels for Motorcycles SAE J1287 Measurement of Exhaust Sound Pressure Levels of Stationary Motorcycles SAE TSB 002 Preparation o
18、f SAE Technical Reports 2.1.2 ANSI Publications Available from American National Standards Institute, 25 West 43rd Street, New York, NY 10036-8002, Tel: 212-642-4900, www.ansi.org. ANSI S1.4-1983 (R2006) with Amd.S1.4A-1985 American National Standard Specification for Sound Level Meters ANSI S1.4-19
19、83 (R1997) American National Standard Specification for Sound Level MetersANSI S1.40-2006 American National Standard Specifications and Verification Procedures for Sound Calibrators ANSI S1.40-1984 American National Standard Specifications and Verification Procedures for Sound Calibrators SAE J2825
20、Revised NOV2012 Page 3 of 11 2.1.3 Code of Federal Regulations Available from U.S. Government Printing Office, 732 North Capitol Street, NW, Washington, DC 20401, Tel: 202-512-0000, http:/www.gpoaccess.gov/cfr/index.html. Title 40, Part 205 Transportation Equipment Noise Emission Controls 2.1.4 IEC
21、Publications Available from International Electrotechnical Commission Regional Center for North America (IEC-ReCNA), 446 Main Street, 16th Floor, Worchester, MA. 01608, or from ANSI (see 2.1.2), www.iec.ch. IEC 60942 Electroacoustics - Sound Calibrators 3. DEFINITIONS 3.1 FIELD CALIBRATION Calibrati
22、on of the sound level meter using an external sound level calibrator for the purpose of ensuring the accuracy of sound level meter readings. 3.2 LONGITUDINAL PLANE OF SYMMETRY As defined in SAE J213. 3.3 MAXIMUM ENGINE SPEED The engine speed in revolutions per minute, sometimes referred to as the “r
23、edline” speed, which is specified by the manufacturer as not to be exceeded. 3.4 TEST SESSION A group of sound level tests made at a single location on a single day. 4. INSTRUMENTATION The following instrumentation shall be used: 4.1 A sound level meter meeting the Type 1, Type S1A, Type 2, or Type
24、S2A requirements of ANSI S1.4-1983 (R2006) or ANSI S1.4 1983 (R1997). 4.1.1 As an alternative to making direct measurements using a sound level meter, a microphone or sound level meter may be used with a recorder or other indicating instrument, provided the system meets the requirements of SAE J184.
25、 4.2 A sound level calibrator with an accuracy of 0.5 dB conforming to IEC 60942 (R2003) Class 1 and/or ANSI S1.40-2006. or ANSI S1.40-1984 4.3 A windscreen which does not affect microphone response more than 1 dB for frequencies of 63 to 4000 Hz and 1.5 dB for frequencies of 4000 to 10 000 Hz. 4.4
26、An original equipment engine speed tachometer. Alternatively other means of determining engine speed with a steady-state accuracy of 3% at the test speed may be used, 4.5 An anemometer with steady-state accuracy of 10% at 9 m/s (20 mph). SAE J2825 Revised NOV2012 Page 4 of 11 5. TEST SITE 5.1 The te
27、st site shall be an open area free of large sound-reflecting surfaces (other than the ground) such as parked vehicles, signboards, or buildings located within 2.5 m (8 ft) of the motorcycle being tested. 5.2 The surface of the ground within the area described in 5.1 shall be paved or hard-packed ear
28、th, level within the typical slope of a paved street or parking lot with no curbs closer than 0.25 m (10 in) of the exhaust outlet being measured. 6. TEST CONDITIONS 6.1 The engine of the motorcycle under test shall be at normal operating temperature during the test. 6.2 The transmission of the moto
29、rcycle under test shall be in neutral. If no neutral is provided, testing should be limited to the Idle Test specified in 6.3.1. 6.3 Test rpm The allowable limits for exhaust sound pressure level (dBA) specified in Section 9 are directly related to the following test speeds: 6.3.1 Idle Test The engi
30、ne shall be run at idle speed. (See 7.2.2) If the engine will not idle without stalling, the throttle shall be opened the minimum amount required to keep the engine running. Determine the minimum amount of throttle opening required by trial and error and then hold the throttle open the minimum amoun
31、t required to keep the engine running. 6.3.2 Engine Speed for Set RPM and Swept RPM Tests TABLE 1 - ENGINE SPEED FOR SET RPM AND SWEPT RPM TESTS AS A FUNCTION OF ENGINE CONFIGURATION Engine Configuration Engine Speed Less than 3 cylinders or more than 4 2000 rpm (200 rpm), or 75% of maximum engine s
32、peed, whichever is less Engines with 3 or 4 cylinders 5000 rpm (200 rpm), or 75% of maximum engine speed, whichever is less 6.4 The ambient sound pressure level (including wind effects) at the test site due to sources other than the motorcycle being measured shall be at least 10 dB lower than the so
33、und pressure level produced by the motorcycle under test. 6.5 Wind speed at the test site during the test shall be less than 9 m/s (20 mph). 6.6 While making sound pressure level measurements, not more than one person other than the rider, the measurer, and an assistant (if necessary) to operate the
34、 throttle shall be within 2.5 m (8 ft) of the motorcycle under test or the microphone, and that person shall be directly behind the measurer on a line through the microphone and the measurer. SAE J2825 Revised NOV2012 Page 5 of 11 7. PROCEDURE 7.1 Operation of the Motorcycle A motorcycle operator sh
35、all sit astride the motorcycle in normal riding position with one or both feet on the ground. Either or both brakes may be applied to keep the motorcycle from moving. Alternatively, the motorcycle may be placed on its center stand or the front wheel of the motorcycle may be placed in a restraint and
36、 the motorcycle may be held in the vertical position with or without the rider sitting astride the motorcycle. For the Idle Test only, the motorcycle may be placed on its side or center stand without the rider sitting astride the motorcycle. 7.2 Test Procedures 7.2.1 Choice of Test Procedure The Idl
37、e Test specified in 7.2.2 should be used where a relatively simple test is needed to identify some vehicles with excessively loud exhaust systems. The Set RPM Test specified in 7.2.3 should be used instead of the Idle Test when the objective is maximizing the identification of vehicles that substant
38、ially exceed Federal EPA standards. Some motorcycles may not be able to maintain the test speed specified in 6.3.2 for 2 seconds under the no load conditions of the Set RPM Test method. Under those circumstances, the Swept RPM Test Procedure specified in 7.2.4 shall be used as an alternative to the
39、Set RPM Test. 7.2.2 Idle Test Procedure The engine shall be run at idle speed for at least 5 seconds. If the engine will not idle without stalling, the throttle shall be opened the minimum amount required to keep the engine running. Determine the minimum amount of throttle opening required by trial
40、and error and then hold the throttle open the minimum amount required to keep the engine running. 7.2.3 Set RPM Test Procedure The motorcycle operator shall run the engine at the test speed specified in 6.3.2 for at least 2 seconds. 7.2.4 Swept RPM Test Procedure The engine shall be slowly accelerat
41、ed to the test rpm specified in 6.3.2. When the specified engine speed is reached, the throttle shall be returned rapidly to the closed position. The test cycle begins when the engine speed is increased above idle and continues until the engine speed reaches the test speed. Ideally, the engine shoul
42、d be accelerated at a uniform rate from idle to the target speed during a period of at least 2 seconds. This may require some trial and error to determine how to manipulate the throttle to achieve a steady increase in speed without causing the maximum engine speed to exceed the target speed by more
43、than 200 rpm. 8. MEASUREMENTS 8.1 For the Idle Test and Set RPM Test the sound level meter shall be set for A-weighting and for slow dynamic response. For the Swept RPM Test procedure specified in 7.2.4 the sound level meter shall be set for A-weighting and fast dynamic response. For the Swept RPM T
44、est a maximum hold setting should be used. (See Appendix A, Section A.3) 8.2 Field Calibration of the Sound Level Meter 8.2.1 Field calibration of the sound level meter using the sound level calibrator (see 4.2) shall be made: a. immediately before the first test of each test session b. immediately
45、after the last test of each test session c. whenever the sound level meter has been dropped or transported from one location to another in a vehicle. SAE J2825 Revised NOV2012 Page 6 of 11 8.2.2 Field calibration of the sound level meter using the sound level calibrator (see 4.2) should be made at i
46、ntervals of no more than 1 h. 8.2.3 Tests conducted since the previous calibration shall be considered valid if the calibration at the end of each test session requires an adjustment of not more than 0.5 dB. 8.3 The microphone shall be located: behind the exhaust outlet, 0.5 m 0.01 m (20 in 1/2 in)
47、from the exhaust outlet, within 0.01 m (1/2 in) of the same height as the exhaust outlet, but at least .2 m above the ground, and at a 45 degrees 10 degrees angle to the normal line of travel of the motorcycle. 8.3.1 The longitudinal axis of the microphone shall be in a plane parallel to the ground
48、plane. The axis of the microphone shall be oriented as specified by the instrument manufacturer (see Figure 1). 8.3.2 If there is more than one exhaust outlet per side refer to Figure 2 to determine the exhaust outlet for microphone placement. 8.4 No wire or other rigid means of distance measurement
49、 shall be attached to the sound measuring system. 8.5 To determine the maximum exhaust sound pressure level, tests shall be made on each side of a motorcycle with an exhaust outlet. If the results of a test conducted on one side exceed the limits specified in Section 9, testing on the other sides is unnecessary to determine non-compliance. 8.6 The following data shall be recorded for each test: 8.6.1 The measured exhaust
