1、 ANSI/ASA S1.20-2012 (Revision of ANSI S1.20-1988 (R2003) AMERICAN NATIONAL STANDARD Procedures for Calibration of Underwater Electroacoustic Transducers Accredited Standards Committee S1, Acoustics Standards Secretariat Acoustical Society of America 35 Pinelawn Road, Suite 114 E Melville, NY 11747-
2、3177ANSI/ASAS1.20-2012 The American National 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 scie
3、ntists and engineers formed in 1929 to increase and diffuse the knowledge of acoustics and to promote its practical applications. ANSI/ASA S1.20-2012 (Revision of ANSI S1.20-1988 (R 2003) AMERICAN NATIONAL STANDARD Procedures for Calibration of Underwater Electroacoustic Transducers Secretariat: Aco
4、ustical Society of America Approved February 17, 2012 by: American National Standards Institute, Inc. Abstract This standard establishes measurement procedures for calibrating underwater electroacoustic transducers. It is a revision of American National Standard S1.20-1988 (R2003). Both primary and
5、secondary calibration procedures are specified for frequencies from a few hertz to a few megahertz. Procedures are specified for determining the measurable characteristics of free-field receive voltage sensitivity, transmitting response, directional response, voltage coupling loss, impedance, and eq
6、uivalent noise pressure. Measurement uncertainty analysis is introduced for these measurement types, with identification of common error sources. Equations are given for the following derived characteristics: beam pattern, directivity factor and index, equivalent two-way beam width, acoustic power o
7、utput and level, electrical power input, transmitting efficiency, open-circuit effective bandwidth, and quality factor. Annexes have been included to address: A) free-field calibration in a laboratory tank, B) medium correction factors, C) measurement of sensitivity and responseinfrasonic and low au
8、dio-frequency range, D) phase of free-field voltage sensitivity via reciprocity method, E) nonlinear effects including cavitation, and F) standard-target method for calibrating active sonars. AMERICAN NATIONAL STANDARDS ON ACOUSTICS The Acoustical Society of America (ASA) provides the Secretariat fo
9、r 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 community (manufacturers, consumers, trade associations, organizations with a ge
10、neral 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 National Standards Institute (ANSI). These standards are developed and published a
11、s 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 approved by ANSI) is responsible for developing, voting upon, and maintaining or r
12、evising 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 and adopted by the Accredited Standards Committees, and approved as American Nati
13、onal 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. Consensus is established when, in the judgment of the ANSI Board of Standards Revie
14、w, 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 objections be considered and that a concerted effort be made towards their resol
15、ution. 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, purchasing, or using products, processes, or procedures not conforming to the Standard
16、s. 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 this Standard. Acoustical Society of America ASA Secretariat 35 Pinelawn Road, Su
17、ite 114E Melville, New York 11747-3177 Telephone: 1 (631) 390-0215 Fax: 1 (631) 390-0217 E-mail: asastdsaip.org 2012 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
18、 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. 2012 Acoustical Society of America All rights reserved iContents 1 Scope . 1 2 Normative referenc
19、es . 1 3 Terminology . 1 4 Letter symbols 1 5 Applications 1 5.1 Application statement . 1 5.2 Measurement types 1 5.3 Transmit and acoustic boundary considerations 1 5.4 Annexes 2 6 Procedures for measuring performance characteristics 2 6.1 Preparing transducers for measurement 2 6.2 Receive sensit
20、ivity methods and measurement conditions 4 6.3 Measurement of sensitivity and response-audio and ultrasonic frequency range . 4 6.4 Directional response of sensitivity and response measurement 9 6.5 Voltage coupling loss 10 6.6 Electrical impedance and admittance measurements 10 6.7 Equivalent noise
21、 pressure 10 7 Data reporting 11 7.1 Data reporting requirements . 11 7.2 Format of data presented . 12 7.3 Specification of orientation . 12 7.4 Directional response graphic representation 13 7.5 Presentation of electrical impedance and admittance data 14 8 Correction factors . 14 8.1 Hydrophone el
22、ectrical loading corrections . 15 8.2 Transmit response corrections for transducers with extension cables . 17 8.3 Attenuation correction . 17 9 Uncertainties in free-field transducer calibrations 17 9.1 Introduction . 17 9.2 Reported uncertainty 18 9.3 Common sources of uncertainty in free-field ca
23、librations. 19 9.4 Uncertainty considerations . 20 10 Computation of derived characteristics 22 10.1 Directionality measures 22 10.2 Acoustic power output (Pac) and acoustic power level (LP) 24 10.3 Electrical power input (Pel) 25 ii 2012 Acoustical Society of America All rights reserved 10.4 Transm
24、itting efficiency () 25 10.5 Open-circuit effective bandwidth 26 10.6 Quality factor (Q) 26 11 References . 27 Annex A Free-field calibration in a laboratory tank . 29 Annex B Medium correction factors 32 B.1 Mass density . 32 B.2 Sound speed . 32 B.3 Absorption coefficient . 33 Annex C Measurement
25、of sensitivity and responseinfrasonic and low audio-frequency range 35 C.1 Coupler reciprocity calibration of a hydrophone . 35 C.2 Secondary sensitivity calibration 37 Annex D Phase of free-field voltage sensitivity via reciprocity method 39 Annex E Nonlinear effects including cavitation . 42 Annex
26、 F Standard-target method for calibrating active sonars . 46 F.1 Standard target . 46 F.2 Theory . 46 F.3 Applicability . 48 Bibliography 51 Figures Figure 1 Transducer arrangements for reciprocity calibration . 5 Figure 2 Left-handed polar coordinate system 12 Figure 3 Example: Directional response
27、 displayed as a polar graph 13 Figure 4 Example: Plots of resistance (R) and reactance (X) vs. frequency (top) and X vs. R (bottom) 14 Figure C.1 Simplified schematic diagram of a liquid coupler . 36 Figure D.1 Measurement framework for supporting the three transducers in-line 40 ANSI/ASA S1.20-2012
28、 2012 Acoustical Society of America All rights reserved iiiForeword This Foreword is for information only and is not a part of ANSI/ASA S1.20-2012 American National Standard Procedures for Calibration of Underwater Electroacoustic Transducers. This standard comprises a part of a group of definitions
29、, standards, and specifications for use in acoustics. It was developed and approved by Accredited Standards Committee S1 Acoustics, under its approved operating procedures. Those procedures have been accredited by the American National Standards Institute (ANSI). The Scope of Accredited Standards Co
30、mmittee S1 is as follows: Standards, specifications, methods of measurement and test, and terminology in the field of physical acoustics, including architectural acoustics, electroacoustics, sonics and ultrasonics, and underwater sound, but excluding those aspects which pertain to biological safety,
31、 tolerances, and comfort. This standard establishes measurement procedures for calibrating underwater electroacoustic transducers and describes forms for presenting and assessing the resultant data. Both primary and secondary calibration procedures are specified for the frequency range from a few he
32、rtz to a few megahertz. This standard is not comparable to any existing ISO Standard. This standard includes six Informative Annexes. At the time this Standard was submitted to Accredited Standards Committee S1, Acoustics, for approval, the membership was as follows: P. Battenberg, Chair R.J. Peppin
33、, Vice-Chair S.B. Blaeser, Secretary Acoustical Society of America A.H. Marsh P.D. Schomer (Alt.) Air-Conditioning, Heating and Refrigeration Institute S.J. Lind D. Abbate (Alt.) American Industrial Hygiene Association D. Driscoll D. Sandfort (Alt.) Campanella Associates A.J. Campanella Casella USA
34、. R. Selwyn R. Brauch (Alt.) ETS-Lindgren Acoustic Systems D. Winker M. Black (Alt.) G.R.A.S. Sound FAX: 631-390-0217; E-mail: asastdsaip.org. AMERICAN NATIONAL STANDARD ANSI/ASA S1.20-2012 2012 Acoustical Society of America All rights reserved 1American National Standard Procedures for Calibration
35、of Underwater Electroacoustic Transducers 1 Scope This standard establishes measurement procedures for calibrating underwater electroacoustic transducers and describes forms for presenting and assessing the resultant data. It is a revision of American National Standard S1.20-1988 (R 2003). 2 Normati
36、ve references ANSI S1.1-1994 (R 2004) American National Standard Acoustical Terminology ANSI/ASA S1.8-1989 (R 2011) American National Standard Reference Quantities for Acoustical Levels 3 Terminology For the purposes of this standard, the terms and definitions given in ANSI S1.1-1994 (R 2004) apply,
37、 except where otherwise specifically re-defined herein. 4 Letter symbols Letter symbols used in this standard comply with those given in ANSI/IEEE Std 260.4-1996 American National Standard Letter Symbols and Abbreviations for Quantities Used in Acoustics (revision and redesignation of ANSI Y10.11-19
38、84), ISO 80000 Quantities and Units, ANSI S1.1-1994 (R 2004) American National Standard Acoustical Terminology, and ANSI/ASA S1.8-1989 (R 2011) American National Standard Reference Quantities for Acoustical Levels. Additional letter symbols, when utilized, are defined within this standard. 5 Applica
39、tions 5.1 Application statement Primary and secondary calibration procedures are specified for the frequencies from a few hertz to a few megahertz. 5.2 Measurement types Procedures are specified for determining the measurable characteristics of free-field sensitivity (more specifically identified as
40、 “free-field voltage sensitivity,” a receive voltage measurement), transmitting current response, transmitting voltage response, directional response, voltage coupling loss, impedance, and equivalent noise pressure. 5.3 Transmit and acoustic boundary considerations Transmit drive conditions and acou
41、stic boundaries can significantly affect the quality of acoustic transmit signal measurements and therefore the quality of the computed measurement parameters. Care should always be taken to work within device-specific operating ranges and under known acoustic conditions. ANSI/ASA S1.20-2012 2012 Ac
42、oustical Society of America All rights reserved 25.4 Annexes The annexes provided with this standard address other related subject matter and are provided for informational purposes. These annexes address free-field calibration in a laboratory tank, medium correction factors, measurement of sensitiv
43、ity and responseinfrasonic and low audio-frequency range, phase of free-field voltage sensitivity via reciprocity method, nonlinear effects including cavitation, and standard-target method for calibrating active sonars. 6 Procedures for measuring performance characteristics 6.1 Preparing transducers
44、 for measurement Transducers must be properly prepared for measurement to ensure an accurate calibration. It is especially important that all surfaces be clean and free of air bubbles. 6.1.1 Use of wetting agents To ensure proper acoustic coupling of the transducer to the water, a wetting agent shou
45、ld be applied to the active face of the transducer after it has been thoroughly cleaned and before it is immersed for acoustic stabilization1(reference clause 6.1.2). The effectiveness of the cleaning operation can usually be determined by observing the meniscus while the transducer is being lowered
46、 into the water. Breaks in the meniscus are indicative of inadequately cleaned areas. When other structure is included along with the transducer (such as a sonar dome), that structure must also be thoroughly cleaned and treated with a wetting agent. 6.1.2 Acoustic stabilization Before any calibratio
47、n measurements are made, the transducer should be placed in the water at the proper test depth for a period of time sufficient for the transducer to attain temperature and hydrostatic pressure equilibrium with the medium. This procedure and that recommended in clause 6.1.1 should help ensure a bubbl
48、e-free active face. The proper test depth is usually dependent upon the device being measured, the geometry of the test tank, and the required conditions. The characteristics of some transducer materials are very dependent on temperature.2It is thus essential that temperature equilibrium be establis
49、hed and that the temperature also be measured and recorded. The stability of the transducer response is one factor in determining temperature equilibrium. 6.1.3 Determine effective acoustic center American National Standard ANSI S1.1-1994 clause 7.48 defines the effective acoustical center of a projector as the “point source from which sound pressure varies inversely as distance.” In this revision, the more commonly used terminology of “acoustic center” has been preferentially selected to replace the terminology “acoustical center.” The acoustic
