1、ANSI/ASA S12.69-2010 AMERICAN NATIONAL STANDARDProcedure for Testing Railroad Horns ex situAccredited Standards Committee S12, NoiseStandards Secretariat Acoustical Society of America 35 Pinelawn Road, Suite 114 E Melville, NY 11747-3177ANSI/ASA S12.69-2010 5HDIILUPHGE$16,2FWREHUThe American Nationa
2、l Standards Institute, Inc. (ANSI) is the national coordinator of voluntary standards development and the clearinghouse in the U.S.A. for information on national and international standards. The Acoustical Society of America (ASA) is an organization of scientists and engineers formed in 1929 to incr
3、ease and diffuse the knowledge of acoustics and to promote its practical applications. ANSI/ASA S12.69-2010 AMERICAN NATIONAL STANDARD Procedure for Testing Railroad Horns ex situ Secretariat: Acoustical Society of America Approved October 6, 2010 by: American National Standards Institute, Inc. Abst
4、ract Federal regulations require the testing of sound emissions from horns located on railroad locomotives. This Standard specifies an alternate method for compliance with the Federal requirements in metropolitan areas where tests cannot be conducted in an outdoor space free of obstructions. The dat
5、a that result from this procedure are equivalent to those that derive from the procedure promulgated by the Federal Railroad Administration as described in 49 CFR Part 229.129. AMERICAN NATIONAL STANDARDS ON ACOUSTICS The Acoustical Society of America (ASA) provides the Secretariat for Accredited St
6、andards Committees S1 on Acoustics, S2 on Mechanical Vibration and Shock, S3 on Bioacoustics, S3/SC 1 on Animal Bioacoustics, and S12 on Noise. These committees have wide representation from the technical community (manufacturers, consumers, trade associations, organizations with a general interest,
7、 and government representatives). The standards are published by the Acoustical Society of America as American National Standards after approval by their respective Standards Committees and the American National Standards Institute (ANSI). These standards are developed and published as a public serv
8、ice to provide standards useful to the public, industry, and consumers, and to Federal, State, and local governments. Each of the Accredited Standards Committees (operating in accordance with procedures approved by ANSI) is responsible for developing, voting upon, and maintaining or revising its own
9、 Standards. The ASA Standards Secretariat administers Committee organization and activity and provides liaison between the Accredited Standards Committees and ANSI. After the Standards have been produced and adopted by the Accredited Standards Committees, and approved as American National Standards
10、by ANSI, the ASA Standards Secretariat arranges for their publication and distribution. An American National Standard implies a consensus of those substantially concerned with its scope and provisions. Consensus is established when, in the judgment of the ANSI Board of Standards Review, substantial
11、agreement has been reached by directly and materially affected interests. Substantial agreement means much more than a simple majority, but not necessarily unanimity. Consensus requires that all views and objections be considered and that a concerted effort be made towards their resolution. The use
12、of an American National Standard is completely voluntary. Their existence does not in any respect preclude anyone, whether he or she has approved the Standards or not, from manufacturing, marketing, purchasing, or using products, processes, or procedures not conforming to the Standards. NOTICE: This
13、 American National Standard may be revised or withdrawn at any time. The procedures of the American National Standards Institute require that action be taken periodically to reaffirm, revise, or withdraw this Standard. Acoustical Society of America ASA Secretariat 35 Pinelawn Road, Suite 114E Melvil
14、le, New York 11747-3177 Telephone: 1 (631) 390-0215 Fax: 1 (631) 390-0217 E-mail: asastdsaip.org 2010 by Acoustical Society of America. This standard may not be reproduced in whole or in part in any form for sale, promotion, or any commercial purpose, or any purpose not falling within the provisions
15、 of the U.S. Copyright Act of 1976, without prior written permission of the publisher. For permission, address a request to the Standards Secretariat of the Acoustical Society of America. Acoustical Society of America 2010 All rights reserved iContents 1 Scope . 1 2 Normative references . 1 3 Terms
16、and definitions . 2 4 Measurement of the horn mounting transfer function 3 4.1 Requirements 3 4.2 Methods for determination of the horn mounting transfer function . 4 5 Calculation of horn output sound pressure level for compliance with 49 CFR Part 229.129 . 5 Bibliography . 6 Tables Table 1 Measure
17、ment and calculation of A-weighted mounting transfer function 5 Table 2 Calculation of FRA equivalent sound level 5 Acoustical Society of America 2010 All rights reserved iiForeword This Foreword is for information only and is not a part of the American National Standard ANSI/ASA S12.69-2010 America
18、n National Standard Procedure for Testing Railroad Horns ex situ. This standard comprises a part of a group of definitions, standards, and specifications for use in noise. It was developed and approved by Accredited Standards Committee S12, Noise, under its approved operating procedures. Those proce
19、dures have been accredited by the American National Standards Institute (ANSI). The Scope of Accredited Standards Committee S12 is as follows: Standards, specifications, and terminology in the field of acoustical noise pertaining to methods of measurement, evaluation, and control, including biologic
20、al safety, tolerance, and comfort, and physical acoustics as related to environmental and occupational noise. This standard is not comparable to any existing ISO Standard. At the time this Standard was submitted to Accredited Standards Committee S12, Noise for approval, the membership was as follows
21、: W.J. Murphy, Chair R.D. Hellweg, Vice-Chair S.B. Blaeser, Secretary 3M Occupational Health FAX: 631-390-0217; E-mail: asastdsaip.org. Acoustical Society of America 2010 All rights reserved vIntroduction The Federal Railroad Administration requires periodic testing of horns used on trains to assure
22、 that they meet minimum and maximum output sound levels. The FRA test protocol specifies environmental conditions that are required in the test environment including meteorological conditions and freedom from interfering sound reflecting surfaces. In many parts of the country it is impractical to co
23、mply with these restrictions as a consequence of normal climatic conditions, adjacencies to metropolitan structures, or community annoyance. This Standard documents a procedure that can be used to test train horns inside maintenance facilities as an alternative to 49 CFR Part 229.129. This procedure
24、 consists of two distinct parts. First is the determination of the difference between measurements of train horn sound levels as required by FRA and the levels measured within a specific maintenance facility. This difference is then applied to future train horn sound level measurements that are made
25、 within the maintenance facility to produce measurement data equivalent to that required by FRA. AMERICAN NATIONAL STANDARD ANSI/ASA S12.69-2010 Acoustical Society of America 2010 All rights reserved 1American National Standard Procedure for Testing Railroad Horns ex situ 1 Scope This Standard speci
26、fies an alternative test procedure to produce horn sound level data equivalent to that produced by the in situ procedure in 49 CFR Part 229.129. This method may be used when: 1. No test location exists that meets the requirements of the regulation. 2. A conforming location exists but testing at that
27、 location creates an unacceptable environmental impact on the surrounding residents. 3. The standard is applicable for a specific locomotive model, horn model, and mounting location and for horns having a fundamental frequency between 200 Hz and 4,000 Hz. Three separate measurements are specified to
28、 produce results that are acoustically valid and to determine the transfer function: measurement of the maximum and minimum compressed air pressures for the fleet, measurement of the A-weighted sound level of the horns under test in situ, and measurement of the horn in a hemi-anechoic room. Once the
29、 transfer function is determined, only measurements in a hemi-anechoic room are needed to produce horn sound levels to evaluate compliance with the Federal requirement. In addition, this method relies on an a priori knowledge of the effect of the horn mounting position on the train. A procedure is s
30、pecified to determine this transfer function on a typical sample of trains. The test procedure relies on mounting the horn under test in a hemi-anechoic room provided with a compressed air supply. Previously determined maximum and minimum air pressures measured during horn soundings are used to test
31、 the horn acoustical output. A-weighted data are used in the evaluation of horn output and mounting transfer function to permit adjustment of the acoustic output measured ex situ in a hemi-anechoic room to correspond with the level that would be measured in situ by the FRA test method. The A-weighte
32、d adjusted levels are then reported per the FRA requirements. 2 Normative references The following referenced documents are indispensable for the application of this standard. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document
33、(including any amendments) applies. ANSI S1.1 American National Standard Acoustical Terminology ANSI S1.4-1983 (R2006) American National Standard Specification for Sound Level Meters ANSI/ASA S12.69-2010 Acoustical Society of America 2010 All rights reserved 2ANSI S12.55-2006 / ISO 3745:2003 America
34、n National Standard Acoustics Determination of sound power levels of noise sources using sound pressure Precision methods for anechoic and hemi-anechoic rooms IEC 61672-1 Electroacoustics Sound level meters Part 1 Specifications IEC 60942 Electroacoustics Sound calibrators 3 Terms and definitions Fo
35、r the purposes of this standard, the terms and definitions given in ANSI S1.1 and the following apply: 3.1 fleet all trains or locomotives of a single type operated by an individual railroad 3.2 hemi-anechoic room test room with a hard reflecting floor whose other surfaces absorb essentially all the
36、 incident sound energy over the frequency range of interest, thereby affording nominally free-field conditions above a reflecting plane 3.3 locomotive item of on-track equipment other than hi-rail, specialized maintenance, or other similar equipment (1) With one or more propelling motors designed fo
37、r moving other equipment; (2) With one or more propelling motors designed to carry freight or passenger traffic or both; or (3) Without propelling motors but with one or more control stands 3.4 nearfield acoustical field measured at a distance closer than that which exhibits homogeny 3.5 noise reduc
38、tion coefficient (NRC) arithmetic mean of sound absorption coefficients at 250, 500, 1000, and 2000 Hz, rounded to the nearest 0.05 metric Sabin per square meter 3.6 standard deviation measure of statistical dispersion, indicating the amount of variation with the n samples NOTE Calculated as: 2111ni
39、ix xn(1) ANSI/ASA S12.69-2010 Acoustical Society of America 2010 All rights reserved 3where xiis the individual sample measurement; and x is the average value of all samples. 3.7 test chamber hemi-anechoic room in which measurements are performed 3.8 transfer function a numerical factor to convert m
40、easurements of horn output sound level measured in a hemi-anechoic room to an equivalent level that would be measured in situ per the FRA protocol specified in 49 CFR Part 229.129 4 Measurement of the horn mounting transfer function 4.1 Requirements 4.1.1 Instrumentation and test location Instrument
41、ation used for measurement of sound pressure levels according to this Standard shall conform to the requirements for Type I or Type II precision according to ANSI S1.4-1983 (R2006) American National Standard Specification for Sound Level Meters or Class 1 or Class 2 of IEC 61672-1. Sound calibrators
42、 shall conform to IEC 60942. The test location shall have a background noise level that is at least 10 dB less than the lowest measured horn level. At the lowest horn frequency, the sound pressure levels measured in the test chamber shall not deviate from the sound pressure level computed using the
43、inverse square law by more than the allowed deviation specified in Table A.2 of ANSI S12.55 / ISO 3745. The lowest frequency is specified by the manufacturer. It is a function of the largest trumpet in the group that comprises the horn. 4.1.2 Measurement of the maximum and minimum air pressures For
44、each fleet, the maximum and minimum air pressure in the locomotive air reservoir shall be measured and noted during six sequential 10-second horn soundings. This shall be repeated a sufficient number of times to yield a statistically valid sample of air pressures to the horn under test. The air pres
45、sure shall be measured during the horn tests on the locomotive. It shall also be measured during the in-chamber measurements to assure that the air pressure falls within the maximum and minimum measured on the locomotive. 4.1.3 Required measurements In order to determine the horn mounting transfer f
46、unction it is necessary to perform the measurements described in 4.2.1 or 4.2.2, and in 4.2.3. ANSI/ASA S12.69-2010 Acoustical Society of America 2010 All rights reserved 44.2 Methods for determination of the horn mounting transfer function 4.2.1 Conforming site unavailable If a suitable in situ mea
47、surement site is unavailable by virtue of interfering reflections, one can be achieved by suspending sound absorbent blankets around the front of the train at a distance outside the nearfield of the front of the train. The blanket shall extend rearward on each side of the train or locomotive under t
48、est to an extent sufficient to break the line of sight between the horn and the reflecting surface. The distance from the horn to the microphone shall be recorded as DIST. The blanket shall have an NRC 0.6. The material should be carried to a height equal to or greater than the height of the locomot
49、ive being tested. After construction of this baffle, carry out the measurements in 4.2.2 noting the distance from the front of the train to the microphone. The microphone shall be located on the center of the track or 10 from the center of the track measured from the horn position. 4.2.2 Conforming site available for transfer function determination only If a suitable in situ site to measure horns can be made available only for use in determining A-weighted horn sound level at 31 mete
