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 reaffirmed, revised, or cancelled. SAE invites your written comments and suggestions. Copyright 2011 SAE International All rights reserved. No part of this publication m
3、ay 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: +1 724-776-4970 (outside U
4、SA) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.org SAE values your input. To provide feedbackon this Technical Report, please visit http:/www.sae.org/technical/standards/J2005_201104 SURFACE VEHICLE RECOMMENDED PRACTICE J2005 APR2011 Issued 1991-12 Reaffirmed 2011
5、-04 Superseding J2005 JUL2004 Stationary Sound Level Measurement Procedure for Recreational Motorboats RATIONALE SAE J2005 has been reaffirmed to comply with the SAE 5-Year Review policy. 1. ScopeThis SAE Recommended Practice establishes the procedure for determining if recreationalmotorboats have e
6、ffective exhaust muffling means when operating in the stationary mode. It is intended as aguide toward standard practice and is subject to change to keep pace with experience and technical advances.1.1 PurposeThis document specifies guidelines for stationary sound level measurements for boats with a
7、bove-water exhaust systems.2. References2.1 Applicable PublicationThe following publications form a part of this specification to the extent specifiedherein.2.1.1 ANSI PUBLICATIONAvailable from the American National Standards Institute, Inc., 25 West 43rd Street,New York, NY 10036-8002.ANSI S1.4Spec
8、ifications for Sound Level Meters2.2 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 Commonwealth Drive, Warrendale, PA 15096-0001.SAE J34Exterior Sound Level Measuremen
9、t Procedure for Pleasure Motorboats2.2.2 ANSI PUBLICATIONSAvailable from the American National Standards Institute, Inc., 25 West 43rd Street,New York, NY 10036-8002.ANSI S1.1Acoustical TerminologyANSI S1.13Methods for the Measurement of Sound Pressure LevelsSAE J2005 Reaffirmed APR2011 Page 2 of 4
10、3. InstrumentationThe following instrumentation shall be used for the measurement required:3.1 A sound level meter which meets ANSI Standard S1.4 Type 1 or Type 2 Specification for Sound Level Meters.3.2 A microphone windscreen that does not affect the overall reading by more than 0.5 dB(A).3.3 A so
11、und level calibrator. (See 5.3.)4. Procedure4.1 Measurement SiteA suitable site is a body of water free of large obstructions or reflective surfaces such asbuildings, boats other than those involved in this procedure, large embankments or breakwaters, etc. for aminimum distance of 3 m (10 ft) from t
12、he boat being measured. The boat being tested shall either be mooredto a dock or lashed to another boat (See Figure 1). If the measurement is made from a dock, care should betaken to minimize the effect of sound waves reflected from the dock. If the measurement is made in openwater, the boat being e
13、valuated shall be lashed to the measurement boat to prevent relative motion and toallow positioning of the microphone in the prescribed location. The measurement boat shall be positioned tominimize reflected sound.FIGURE 1TYPICAL BOAT POSITION4.2 Boat OperationThe engine shall be operated at low idl
14、e speed within the engine manufacturersrecommended operating range, in neutral gear if so equipped. For motorboats without a neutral gear, theengine shall be operated at its lowest operational speed. The engine shall be operated for a sufficient amountof time to allow water to flow through the exhau
15、st system before taking sound level measurements. If sufficientwater flow cannot be determined, the engine shall be operated for at least 60 s before proceeding with thesound level measurements.4.3 Measurements4.3.1 The microphone shall be placed at a distance of 1.2 to 1.5 m (4 to 5 ft) above the w
16、ater and no closer than1 m (3.3 ft) from the vertical projection of any part of the boat Including the swim platform (where applicable)in the area adjacent to the exhaust outlet(s).SAE J2005 Reaffirmed APR2011 Page 3 of 4 4.3.2 The meter shall be set for slow response and the A-weighting network.4.3
17、.3 The observer reading the meter shall not be closer than arms length from the microphone to minimize soundreflections.4.3.4 The applicable reading shall be the average sound level measured during a period when the backgroundsound level is at least 10 dB lower than the measured sound level. Backgro
18、und sound level includes windeffects, noise from boats other than the one being measured, wave action, boat wakes, and other extraneousnoises. Peak readings of intermittent sound levels created by wave slaps or changes in sound level due towave action and/or engine speed variation shall not be inclu
19、ded in the applicable reading.4.3.5 The observer shall record the applicable reading and the background sound levels taken immediately beforeand immediately after the applicable reading.5. General Requirements5.1 The measurements shall be conducted only by persons qualified by training to perform th
20、ese measurements.5.2 Proper use of all test instrumentation is essential to obtain valid measurements. Operating manuals or otherliterature furnished by the instrument manufacturer should be consulted for both recommended operation ofthe instrument, and precautions to be observed.5.3 Proper acoustic
21、al calibration shall comprise the complete measurement system including extension cables,etc. Field calibration shall be performed immediately before and after each test sequence.5.4 A measurement shall be invalid if changes in the background sound level affect the applicable reading.5.5 The use of
22、the word “shall” in the procedure is to be understood to be mandatory, while the word “should” is tobe understood as advisory.6. Notes6.1 Marginal IndiciaThe change bar (l) located in the left margin is for the convenience of the user in locatingareas where revisions have been made to the previous i
23、ssue of the report. An (R) symbol to the left of thedocument title indicates a complete revision of the report.PREPARED BY THE SAE MARINE TECHNICAL COMMITTEEREAFFIRMED BY THE SAE MARINE TECHNICAL STEERING COMMITTEESAE J2005 Reaffirmed APR2011 Page 4 of 4 APPENDIX AThis procedure has been developed a
24、s a guide for governmental agencies to enforce the requirement foreffective muffling means in recreational motorboats. Likewise, marine muffler manufacturers and recreationalcraft manufacturers will benefit from this document when evaluating compliance of their products with local/state noise regula
25、tions.NOTEThe measured sound level as obtained with this procedure is not an indication of maximumoperational sound levels for recreational motorboats.In most applications involving thru-transom exhaust, the microphone should be positioned as follows:a. 1 m (3.3 ft) aft of the intersection of the ve
26、rtical plane of the aft-most part of the hull (including the swimplatform where applicable) and the vertical plane of the port-most or starboard-most extension of thehull.b. 1.2 to 1.5 m (4 to 5 ft) above the surface of the water.c. Free-field microphones shall be oriented toward the exhaust outlet(
27、s)d. Grazing incidence microphones shall be oriented at an angle of 45 degrees with respect to the plane ofthe exhaust outlet(s).Care must be taken to avoid erroneous readings due to sound reflections by proper positioning of theenforcement boat such that minimal extension of the enforcement hull protrudes into the area surrounding themicrophone during measurements. Only one enforcement boat shall be in the area where measurements arebeing taken.
