ASA S12 72-2015 American National Standard Procedure for Measuring the Ambient Noise Level in a Room.pdf

1、 ANSI/ASA S12.72-2015 AMERICAN NATIONAL STANDARD Procedure for Measuring the Ambient Noise Level in a Room Accredited Standards Committee S12, Noise Standards Secretariat Acoustical Society of America 1305 Walt Whitman Road, Suite 300 Melville, NY 11747ANSI/ASAS12.72-2015 AMERICAN NATIONAL STANDARDS

2、 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 Animal Bioacoustics, and S12 on Noise. These committees have wide representation from the technical

3、 community (manufacturers, consumers, trade associations, organizations with a general interest, 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 N

4、ational 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 governments. Each of the Accredited Standards Committees (operating in accordance with procedures a

5、pproved 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 liaison between the Accredited Standards Committees and ANSI. After the Standards have been produced

6、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 Standard implies a consensus of those substantially concerned with its scope and provisions. Co

7、nsensus 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 more than a simple majority, but not necessarily unanimity. Consensus requires that all views and

8、 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 anyone, whether he or she has approved the Standards or not, from manufacturing, marketing, purch

9、asing, 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 Standards Institute require that action be taken periodically to reaffirm, revise, or withdraw

10、this Standard. Acoustical Society of America ASA Secretariat 1305 Walt Whitman Road, Suite 300 Melville, New York 11747 Telephone: 1 (631) 390-0215 Fax: 1 (631) 923-2875 E-mail: asastdsacousticalsociety.org 2015 by Acoustical Society of America. This standard may not be reproduced in whole or in par

11、t 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, address a request to the Standards Secretariat of the Acoustical Society of America. 20

12、15 Acoustical Society of America All rights reserved iContents 1 Scope . 1 2 Purpose 2 3 Applications 2 4 Normative references 2 5 Terms and definitions, nomenclature and mathematical descriptions . 3 5.1 Terms and definitions 3 5.2 Nomenclature 6 5.3 Mathematical descriptions . 7 6 Types of sound 8

13、 6.1 Temporal characteristics . 8 6.2 Frequency characteristics 10 6.3 Spatial characteristics 11 7 Types of acoustical environments . 12 7.1 Size and reverberation 12 7.2 Function . 13 8 Instrumentation 15 9 Test conditions . 15 10 Allowable measurement volume 16 11 Measurement procedure 16 11.6 Su

14、rvey method . 17 11.7 Engineering method. 17 12 Background noise correction . 18 12.1 Definition 18 12.2 Measurement methods 18 12.3 Background noise correction . 18 13 Criteria evaluation 19 14 Test report 19 14.1 Measurement objectives 20 14.2 Test conditions . 20 14.3 Measured sound pressure leve

15、ls . 20 Annex A (informative) Typical noise metrics for various indoor sound level measurements . 21 Annex B (informative) Sample data sheet for indoor sound level measurements . 22 Annex C (informative) Example of Using ANSI S12.72 for School Classrooms (Survey Method) . 23 Bibliography . 25 2015 A

16、coustical Society of America All rights reserved ii Figures Figure 1 Recommended motion for handheld space-average measurement 17 Tables Table 1 Quantity symbols and unity symbols. 6 Table A.1 Appropriate indoor sound level metrics 21 2015 Acoustical Society of America All rights reserved iiiForewor

17、d This Foreword is for information only and is not a part of the American National Standard ANSI/ASA S12.72-2015 American National Standard Procedure for Measuring the Ambient Noise Level in a Room. As such, this Foreword may contain material that has not been subjected to public review or a consens

18、us process. In addition, it does not contain requirements necessary for conformance to the standard. 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

19、 operating procedures. 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, evaluatio

20、n, and control, including biological 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 appr

21、oval, the membership was as follows: W.J. Murphy, Chair S.J. Lind, Vice-Chair S.B. Blaeser, Secretary 3M Occupational Health Fax: (631) 923-2875; E-mail: asastdsacousticalsociety.org. 2015 Acoustical Society of America All rights reserved vi Introduction The total ambient sound that exists in a room

22、 is usually due to a composite of many different sounds with different strengths and frequency content. The composite sound may be a combination of background noise and sound from a single identifiable source, it may be a combination from several individual sources, and it may include reflections fr

23、om room surfaces or reflecting objects. This standard is primarily concerned with the measurement of the level of the composite sound at a given point or a region of an enclosed space within a building. The way in which the sound pressure level varies with time (temporal pattern), how it varies over

24、 frequency (frequency content), and how it varies from one physical point to another (spatial distribution) within a room are often important. The desire to quantify these aspects has led, unfortunately, to a preponderance of metrics and descriptors in use today, some quite complicated and some limi

25、ted to very specific applications. Fortunately, the advent of modern digital instruments of relatively low cost and wide availability, and the efforts by standardization bodies have led to a general consensus on only a small number of descriptors. This standard may be used to measure the time- and s

26、pace-average sound pressure level in octave and fractional octave bands as well as frequency-weighted full spectrum level descriptors like the A-weighted, C-weighted, and linear (unweighted) sound pressure levels. The choice of frequency weighting will depend upon the specified or desired noise crit

27、erion. There are many reasons for measuring sound pressure levels in rooms. However, most purposes fall into two groups: 1) sound pressure levels measured in order to characterize a source, and 2) sound pressure levels measured in order to characterize an environment. Regardless of the reasons, or w

28、hether one is trying to characterize a source or an environment, the process will involve individual measurements of the sound pressure level at one or more specific points in space. This is the focus of this standard. The particular reasons or applications for the measurements are dealt with only s

29、uperficially. This standard is intended to be used by practitioners in the field as well as by members of the general public who have little or no special technical training in areas relating to acoustics. One of the goals of publishing this standard is to make the practice of making an accurate sou

30、nd pressure level measurement more widespread and comfortable. It is anticipated that standards, test codes, government regulations, purchase specifications, design specifications, or similar documents requiring the measurement of sound pressure levels in rooms will refer to this standard in a form

31、such as “.(at the specified point or points) the (specified type of) sound pressure level shall be measured in accordance with ANSI/ASA S12.72-2015.” AMERICAN NATIONAL STANDARD ANSI/ASA S12.72-2015 2015 Acoustical Society of America All rights reserved 1American National Standard Procedure for Measu

32、ring the Ambient Noise Level in a Room 1 Scope This standard specifies requirements and procedures for the measurement of sound pressure levels in building spaces or rooms. These requirements and procedures apply ideally to measurements performed in unoccupied spaces, with normal building services a

33、nd HVAC equipment operating under relatively steady conditions. This standard, however, does not exclude measurements in occupied rooms. Transient noise sources, which for the purposes of this standard are defined as sounds with a duration of less than 10 seconds, are specifically excluded from this

34、 standard. This standard also does not apply to measurements made outdoors. The requirements in this standard (identified by the use of the word shall) are to be understood as conditions on the measurements that must be met in order to state that such measurements have been made in conformance with

35、this American National Standard. The guidelines and recommendations (identified by the use of the word should) are to be understood as conditions that will generally improve the accuracy, validity, applicability, documentation, and reporting of the measurement data but that are not mandatory for con

36、formance. The type of sounds considered by this standard may differ widely in spectral characteristics. The sound to be measured may be essentially broadband or may contain discrete tones or narrow bands of noise. The frequency range covered by the requirements of this standard depends on the specif

37、ic type of sound level meter or instrumentation being used, but, in general, the frequency content of the sound being measured should be contained within the range covered by the octave bands having center frequencies from 16 Hz to 8.0 kHz. The sound pressure levels of sounds whose energy is concent

38、rated outside of this range may not be measured accurately according to the procedures of this standard. This standard may be used to obtain one-third octave or octave-band sound pressure level spectra or single-number sound descriptors such as the time-average A-weighted overall sound level (also c

39、alled the equivalent-continuous A-weighted sound pressure level). The standard may also be used to obtain the NC (noise criterion) level, the RC (room criterion) level, or other sound metric applicable to steady-state sounds which can be described by one-third octave bands. To accommodate a wide ran

40、ge of applications, this standard provides two distinct measurement grades: 1) Survey method Provides a quick but only approximate noise evaluation. Generally adequate for an initial building commissioning process. 2) Engineering method Provides an accurate assessment of the noise level in a room. G

41、enerally sufficient to establish compliance relative to a noise criterion. To avoid misinterpretation of noise test results obtained according to this standard, it is essential that the data be clearly marked as to whether they pertain to the survey or the engineering method. This is especially crit

42、ical when the results are used to establish compliance to building design criteria. If the survey method fails to conclusively determine the compliance of a space with a given criterion, then the engineering method shall be used. Ideally, engineering method tests should be conducted with ANSI/ASA S1

43、2.72-2015 2015 Acoustical Society of America All rights reserved 2the guidance of an experienced acoustical consultant, a professional engineer with appropriate sound level measurement experience, or a noise control engineer who has attained Board Certification through the Institute of Noise Control

44、 Engineering of the United States of America. 2 Purpose This standard has a number of purposes, all equally important. They are as follows: 1) To establish uniform procedures for measuring steady-state sound pressure levels in building spaces. 2) To facilitate the drafting of test codes, regulations

45、, and the like by standardizing the basic requirements of sound pressure level measurements common to most of these documents. Rather than reiterating these requirements, the test codes and similar documents may simply refer to this document for the essential requirements. 3) To help make the proced

46、ures of acoustical measurements more accessible to regulatory personnel and the general public through clearly defining the steps and types of instrumentation necessary. 3 Applications This standard is applicable to the acquisition of sound pressure level data for use by a wide range of parties who

47、may be interested in quantifying the sound levels of building spaces. Activities which would benefit from application of this standard include: Building commissioning, when approximate (survey method) measurements of numerous spaces are needed to identify the most critical areas. Building noise cert

48、ification, especially when approximate (survey method) data are insufficient to establish compliance with design criteria. In those situations, the (engineering) methods needed to ensure more precise and repeatable data are defined. Resolution of noise problems, when stable measurements of sound und

49、er various operating conditions or with various equipment active (building service, HVAC or other) are needed for diagnostic purposes. Characterization of existing building spaces, for use in establishing design criteria for related applications. 4 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 (including any amendments) applies. ANSI/ASA S1.1-2013 Americ