1、ANSI/ASA S12.10-2011/Part 2 AMERICAN NATIONAL STANDARD Acoustics - Measurement of Airborne Noise Emitted by Information Technology and Telecommunications Equipment - Part 2: Declaration of Noise Emission Levels Secretariat: Acoustical Society of America Approved on August 17, 2011 by: American Natio
2、nal Standards Institute, Inc. Abstract This Standard specifies procedure and requirements of the verification of noise emission levels of information technology and telecommunications equipment. Hitherto, a wide variety of methods have been applied by individual manufacturers and users to satisfy pa
3、rticular equipment or application needs. These diverse practices have, in many cases, made comparison of noise emission difficult. This Standard unifies the procedure and requirements that make the declared noise emission levels consistent for information technology and telecommunications equipment.
4、 This Standard is technically identical to parts of ECMA-109 (2010). AMERICAN NATIONAL STANDARDS ON ACOUSTICS The Acoustical Society of America (ASA) provides the Secretariat for Accredited Standards Committees S1 on Acoustics, S2 on Mechanical Vibration and Shock, S3 on Bioacoustics, S3/SC 1 on Ani
5、mal Bioacoustics, and S12 on Noise. These committees have wide representation from the technical community (manufacturers, consumers, trade associations, organizations with a general interest, and government representatives). The standards are published by the Acoustical Society of America as Americ
6、an 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 service to provide standards useful to the public, industry, and consumers, and to Federal, State, and local gov
7、ernments. 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 Standards. The ASA Standards Secretariat administers Committee organization and activity and provides liais
8、on 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 by ANSI, the ASA Standards Secretariat arranges for their publication and distribution. An American National
9、 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 agreement has been reached by directly and materially affected interests. Substantial agreement means much m
10、ore 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 of an American National Standard is completely voluntary. Their existence does not in any respect preclude a
11、nyone, 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 American National Standard may be revised or withdrawn at any time. The procedures of the American National
12、 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 Melville, New York 11747-3177 Telephone: 1 (631) 390-0215 Fax: 1 (631) 390-0217 E-mail: asastdsaip.org 2011 by Aco
13、ustical 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 of the U.S. Copyright Act of 1976, without prior written permission of the publisher. For permission, addre
14、ss a request to the Standards Secretariat of the Acoustical Society of America. Acoustical Society of America 2011 All rights reserved iContents 1 Scope 1 2 Normative references 1 3 Terms and definitions 2 4 Conformance requirements . 4 4.1 For declaration . 4 4.2 For verification 4 5 Declared noise
15、 emission values 4 5.1 General 4 5.2 Determination of the A-weighted sound power level, LWA5 5.3 Determination of the A-weighted emission sound pressure level, LpA, at the operator (bystander) position(s) . 5 6 Presentation of declared noise emission values . 5 6.1 Required information 5 6.2 Additio
16、nal information . 5 7 Verification of the declared noise emission values . 6 7.1 General 6 7.2 Verification of LWAdfor a batch of equipment . 6 Annex A (normative) Procedure for determining declared noise emission values 7 A.1 General 7 A.2 Determination of the declared A-weighted sound power level
17、for a batch of equipment, LWAd7 A.2.1 Initial considerations . 7 A.2.2 Determination of the sample mean and sample total standard deviation of the batch 7 A.2.3 Determination of the value to declare 8 A.3 Determination of the declared A-weighted emission sound pressure level, LpAm, for a batch of eq
18、uipment 9 Annex B (informative) Examples of noise emission declarations 10 Annex C (informative) Character of noise . 12 C.1 General 12 C.2 Annex status 12 C.3 Determination of the character of noise . 12 C.4 Information on impulsive noise and prominent discrete tones . 12 Tables Table A.1 Guard ban
19、d value, G 9 Acoustical Society of America 2011 All rights reserved ii Foreword This Foreword is for information only and is not a part of the American National Standard ANSI/ASA S12.10-2011/Part 2 American National Standard Acoustics Measurement of Airborne Noise Emitted by Information Technology a
20、nd Telecommunications Equipment Part 2: Declaration of Noise Emission Levels. 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.
21、Those procedures 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, includi
22、ng biological safety, tolerance, and comfort, and physical acoustics as related to environmental and occupational noise. This document adopts, with permission, parts of the 5thEdition of ECMA-109 (2010). At the time this Standard was submitted to Accredited Standards Committee S12, Noise, for approv
23、al, the membership was as follows: W.J. Murphy, Chair R.D. Hellweg, Vice-Chair S.B. Blaeser, Secretary 3M Occupational Health and Environmental Safety Division E.H. Berger Acoustical Society of America . R.D. Hellweg D. Lubman (Alt.) Air-Conditioning, Heating and Refrigeration Institute S. Lind D. A
24、bbate (Alt.) Air Movement and Control Association, Inc. J.A. Brooks M. Stevens (Alt.) Alcoa Inc. . W.D. Gallagher American Academy of Audiology D. Ostergren S. Gordon-Salant (Alt.) American Academy of Otolaryngology Head and Neck Surgery R.A. Dobie L.A. Michael (Alt.) American Industrial Hygiene Ass
25、ociation . D. Driscoll . S.N. Hacker (Alt.) American Speech-Language-Hearing Association . L.A. Wilber . V. Gladstone (Alt.) Caterpillar, Inc. . K.G. Meitl Compressed Air and Gas Institute . R.C. Johnson . D.R. Bookshar (Alt.) Acoustical Society of America 2011 All rights reserved iiiCouncil for Acc
26、reditation in Occupational Hearing Conservation . Vacant .L.D. Hager (Alt.) Emerson Electric Copeland Corporation A.T. Herfat G. Williamson (Alt.) ETSLindgren Acoustic Systems . D. Winker M. Black (Alt.) ExxonMobil . B. Moulton A. Ratliff (Alt.) G.R.A.S. Sound FAX: 631-390-0217; E-mail: asastdsaip.o
27、rg. Acoustical Society of America 2011 All rights reserved vIntroduction In order for equipment noise emission data to be useful, uniform methods are necessary for the following purposes: Measurement of noise emission values ANSI/ASA S12.10/Part 1 specifies procedures for measuring sound power and p
28、ressure levels of information technology and telecommunications equipment based on the basic noise emission standards ANSI/ASA S12.51 / ISO 3741, ANSI/ASA S12.54 / ISO 3744, ANSI/ASA S12.55 / ISO 3745 and ISO 11201. Determination of the noise emission values to be declared ANSI/ASA S12.10/Part 2 spe
29、cifies procedures for determination and declaration of noise emission levels of information technology and telecommunications equipment following guidelines of the basic standard ISO 4871 and statistical methods of ISO 7574 series. Presentation of declared noise emission values For the presentation
30、of declared noise emission values, it is of prime importance to declare A-weighted sound power levels, LWA. It is recognized, however, that users still desire information on A-weighted emission sound pressure levels, LpA. Therefore, this Standard specifies that both quantities shall be declared. In
31、the preparation of this Standard divergences of opinion have been found among various national and international organizations as to the most useful way of presenting noise emission values. In order to avoid any misunderstanding between presentation of sound power levels in decibels re 1 pW and emis
32、sion sound pressure levels in decibels re 20 Pa, this Standard expresses sound power level values in bels and emission sound pressure level values in decibels, to alleviate the divergences of opinion mentioned. As an option, methods for determination and presentation of subjective characteristics of
33、 noise emission are presented in Annex C. Verification of declared noise emission values ANSI/ASA S12.10/Part 2 specifies the verification procedure and requirements of declared noise emission values of information technology and telecommunications equipment following the basic methods defined in IS
34、O 7574. The verification procedure and requirements specified in this standard are restricted to verifying declared A-weighted sound power levels, LWad, only. The reasons for using bels for declared A-weighted sound power levels are: 1. To avoid user confusion In this Standard the A-weighted sound p
35、ower level is the primary descriptor for the noise emission levels. The A-weighted emission sound pressure level is the secondary, complementary descriptor. Many manufacturers and users of information technology and telecommunications equipment have historically used A-weighted emission sound pressu
36、re levels in decibels. Since customers want both sound power and emission sound pressure levels, this Standard utilizes both quantities. Without including reference values (i.e., 1 pW and 20 Pa), expressing both declared sound power levels and declared emission sound pressure levels in decibels tend
37、s to cause confusion. To distinguish the two, this Standard expresses sound power level values in bels where a bel is 10 decibels re 1pW, and expresses emission sound pressure level values in decibels re 20 Pa. Acoustical Society of America 2011 All rights reserved vi 2. To avoid misapplication of d
38、ata If declared A-weighted sound power levels were expressed in decibels, users may mistakenly compare the sound power levels with workplace regulations of immission sound pressure levels. In many information technology and telecommunications equipment applications, the sound power level (in decibel
39、s) value of the equipment is significantly larger than the immission sound pressure level (in decibels) value measurable in the workplace. The later, immission value is the level at human ear location in a given environment which changes with the acoustic environment, such as room size and acoustica
40、l attenuation property of floor, wall, ceiling, doors, windows and room partitions, etc., while the sound power level is an intrinsic property of equipment that does not change with the environment it is placed in. 3. To promote the use of ANSI/ASA S12.10/Part 2 The purpose of ANSI/ASA S12.10/Part 2
41、 is to provide uniform methods of presenting declared noise emission values to users. Without using bels, this objective would be lost since there would be an incentive for some manufacturers to report emission sound pressure levels instead of sound power levels. The primary descriptor of informatio
42、n technology and telecommunications equipment noise is the declared A-weighted sound power level, LWAd. If ANSI/ASA S12.10/Part 2 were to use decibels for declared A-weighted sound power levels, manufacturers who do not implement this Standard would be at a competitive advantage by reporting emissio
43、n sound pressure levels in decibels which would be lower than the declared sound power levels also in decibels. Not only would the user be confused and unable to tell the difference, but the manufacturer who followed ANSI/ASA S12.10/Part 2 would be at an unfair competitive disadvantage. To eliminate
44、 this confusion and disadvantage and to promote the uniform reporting of declared noise emission values, the declared A-weighted sound power levels must be reported in bels. 4. To use a method based on successful experience For several years, many international companies have reported A-weighted sou
45、nd power levels in bels and A-weighted emission sound pressure levels in decibels without confusion of their customers. Indeed, their customers have been able to distinguish easily between the important difference of sound power level and emission sound pressure level, and the users have not lost th
46、e significance of the digit after the decimal mark. Actually they have been less confused; without using bels, they would wonder: “which decibel do I compare to our specification?“ 5. To be consistent with other standards The use of bels for declared A-weighted sound power levels is consistent with
47、ISO 4871 Acoustics - Declaration and verification of noise emission values of machinery and equipment and with ISO 7574-1 Acoustics - Statistical methods for determining and verifying stated noise emission values of machinery and equipment - Part 1: General considerations and definitions. The declar
48、ed A-weighted sound power level, LWAd, is a statistical maximum value and corresponds to the “declared single-number noise emission value“ in ISO 4871 and “labeled value“ in ISO 7574-1. The definition of “declared single-number noise emission value“ in ISO 4871 and “labeled value“ in ISO 7574-1 has
49、a note which states that in some cases, the labeled value may be expressed as the numerical value of sound power level in decibels divided by 10, given with one digit after the decimal mark, i.e. in bels. ANSI/ASA S12.10/Part 2 recognizes that the sound power is determined in decibels, according to ANSI/ASA S12.10/Part 1 which is based upon ANSI/ASA S12.51 / ISO 3741, ANSI/ASA S12.54 / ISO 3744, and ANSI/ASA S12.55 / ISO 3745, and is then reported to the customers as a declared value in bels. AMERICAN NATIONAL STANDARD ANSI/ASA S12.10-2011/Part
