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.orgSAE values your input. To provide feedbackon this Technical Report, please visit http:/www.sae.org/technical/standards/J1970_201102SURFACEVEHICLERECOMMENDEDPRACTICEJ1970 FEB2011 Issued 1991-12 Revised 2011-02Supers
5、eding J1970 SEP2003 (R) Shoreline Sound Level Measurement Procedure for Recreational Motorboats RATIONALE SAE J1970 was originally developed for the specific purpose of measuring boat noise at the shoreline of recreational boating areas. Shoreline noise from recreational boats has now become a major
6、 public health and safety issue as a result of large “offshore-style” boats that are now being used on small inland lakes and rivers. The original version of SAE J1970 did not adequately define the applicable measurement restrictions (Section 4) and, as a result, the exact meaning of “shoreline nois
7、e” was often restricted to the point of rendering the procedure unusable in perhaps a majority of shoreline situations. This revision allows measurements to be made, for instance, at virtually any distance inland from the shoreline, thereby facilitating measurements to be performed under conditions
8、where, for example, wave noise at the waters edge produces unacceptably high ambient noise levels thereby rendering the original version to be unusable. Subsequent modifications regarding the required vertical distance from the waterline to the microphone have been included in the revised version th
9、ereby allowing sound level measurements to be performed that are much more realistic in terms of exposure of shoreline residents to boat noise. For practical reasons some restrictions such as the one regarding “immediate” equipment calibration have been eliminated to avoid conflicts regarding a spec
10、ified time limit. 1. SCOPE This SAE Recommended Practice establishes the procedure for measuring the sound level of recreational motorboats in the vicinity of a shore bordering any recreational boating area during which time a boat is operating under conditions other than stationary mode operation.
11、It is intended as a guide toward standard practice and is subject to change to keep pace with experience and technical advances. 1.1 Purpose This document specifies guidelines for sound level measurements made from the shoreline of recreational boating areas and is intended for recreational motorboa
12、ts only. 2. REFERENCES 2.1 Applicable Documents The following publications form a part of this specification to the extent specified herein. Unless otherwise indicated, the latest issue of SAE publications shall apply. Copyright SAE International Provided by IHS under license with SAENot for ResaleN
13、o reproduction or networking permitted without license from IHS-,-,-SAE J1970 Revised FEB2011 Page 2 of 52.1.1 IEC Publications Available from International Electrotechnical Commission, 3, rue de Varemb, P.O. Box 131, CH-1211, Geneva 20, Switzerland. IEC 60942 Electroacoustics - Sound calibrators IE
14、C 61672 Electroacoustics - Sound level meters 2.2 Related Publications The following publications are provided for information purposes only and are not a required part of this SAE Technical Report.2.2.1 SAE Publications Available from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-
15、0001, Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.org.SAE J34 Exterior Sound Level Measurement Procedure for Pleasure Motorboats SAE J2005 Stationary Sound Level Measurement Procedure for Recreational Motorboats 2.2.2 ASA Publications Available from Acoustical So
16、ciety of America, http:/asa.aip.org or from ANSI, 25 West 43rd Street, New York, NY 10036-8002, http:/www.ansi.org.ANSI S1.1 Acoustical Terminology ANSI S1.13 Measurement of Sound Pressure Levels in Air 3. INSTRUMENTATION The following instrumentation shall be used for the measurement required. 3.1
17、A sound level meter which meets IEC Standard 61672-1 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 dBA. 3.2.1 A sound calibrator which meets IEC Standard 60942 specification for Sound Calibrators. 4. PROCE
18、DURE 4.1 Measurement Site A suitable site is anywhere inland or no more than 6 m (20 ft) from the waters edge out into a body of navigable water 4.2 Boat Operation 4.2.1 The applicable reading does not require the measured boat to be at any specific distance from the shoreline or microphone. Copyrig
19、ht SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE J1970 Revised FEB2011 Page 3 of 54.3 Measurements 4.3.1 The microphone/sound level meter location is subject to the following restrictions: 4.3.1.1 The mi
20、crophone/sound level meter positioning with respect to the shoreline shall be located at a distance out into the water of no more than 6 m (20 ft) from the waters edge. No distance restrictions with respect to the shoreline shall apply with regard to landward location. 4.3.1.2 The microphone/sound l
21、evel meter may be either hand-held or mounted on a tripod and the surface beneath the microphone/sound level meter is unspecified, whether it be water, sand, rock, grass, wood, dirt, aluminum, fiberglass, etc. 4.3.1.3 The vertical distance between the microphone/sound level meter and the underlying
22、surface shall be any distance equal to or greater than 0.91 m (3 ft) 4.3.1.4 The microphone/sound level meter shall be located no closer than 3 m (10 ft) in front of any large obstructions or reflective surfaces, e.g., buildings/vertical walls, etc. such that sound waves may be reflected back toward
23、s the microphone/sound level meter. Trees with trunks larger than 0.3 m (1 ft) are subject to the same 3 m (10 ft) limitation. Shrubs, grass and leafy vegetation are non-reflective and are not prohibited. 4.3.1.5 The sound level meter shall be pointed in the general direction of the measured boat du
24、ring measurements. 4.3.2 The meter shall be set for the A-weighting network and slow response and subsequent measurements shall be designated as AS-weighted. 4.3.3 The observer reading the meter shall not be closer to the device than is necessary to observe the sound level reading. Only one other pe
25、rson may be within 15 m (50 ft) of the microphone when measuring from a dock or shoreline, and that person shall be directly behind the observer reading the meter. 4.3.4 The applicable reading shall be the maximum AS-weighted sound pressure level of the boat (Lpasmax) measured during a period when t
26、he ambient sound level is at least 6 dB lower than the maximum AS-weighted sound pressure level of the boat. Ambient sound level includes wind effects, noise from boats other than the one being measured, wave action, boat wakes, and other extraneous noises. 4.3.5 The observer shall record the applic
27、able reading and the ambient sound levels taken before and after the applicable reading as is necessary whereupon the following corrections to the observed maximum boat sound pressure level shall be applied: Difference in the maximum Sound Pressure Level of the boat and the ambient Sound Pressure Le
28、vel (dB) Correction in dB to be applied to the maximum Sound Pressure Level of the boat (dB) 10 0 6 to 9 -1 4.3.6 When sound level readings are taken from a boat, the sound level meter shall be held at arms length outside of the boat while complying with the restrictions as specified in 4.3.1. 5. GE
29、NERAL REQUIREMENTS 5.1 The measurements shall be conducted only by persons qualified by training to perform these measurements. 5.2 Proper use of all test instrumentation is essential to obtain valid measurements. Operating manuals or other literature furnished by the instrument manufacturer should
30、be consulted for both recommended operation of the instrument, and precautions to be observed. 5.3 Proper acoustical calibration shall comprise the complete measurement system including extension cables, etc. Field calibration shall be performed before and after each test sequence. Copyright SAE Int
31、ernational Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE J1970 Revised FEB2011 Page 4 of 55.4 A measurement shall be invalid if changes in the ambient sound level affect the applicable reading. 5.5 The use of the word “sh
32、all” in the procedure is to be understood to be mandatory. The use of the word “should” is to be understood as advisory. The use of the word “may” is to be understood as permissive. 6. NOTES 6.1 Marginal Indicia A change bar (l) located in the left margin is for the convenience of the user in locati
33、ng 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, n
34、or in documents that contain editorial changes only. PREPARED BY THE SAE MARINE TECHNICAL STEERING COMMITTEE Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE J1970 Revised FEB2011 Page 5 of 5APPEN
35、DIX A A.1 This procedure may be used for the measurement of sound emitted by recreational motorboats in use on waterways where sound level restrictions apply. Sound level is a function of the exhaust system, the boat hull, the manner of boat operation, e.g., distance from shore, engine speed and trim angle, and other factors. Background information is included in the SAE J1970 rationale statement. Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
