1、BRITISH STANDARDBS EN 61161:2007Ultrasonics Power measurement Radiation force balances and performance requirementsThe European Standard EN 61161:2007 has the status of a British StandardICS 17.140.50g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40
2、g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS EN 61161:2007This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 October 2007 BSI 2007ISBN 978 0 580 50695 6National forewordThis British St
3、andard was published by BSI. It is the UK implementation of EN 61161:2007. It is identical with IEC 61161:2006. It supersedes BS EN 61161:1995 which is withdrawn.The UK participation in its preparation was entrusted to Technical Committee EPL/87, Ultrasonics.A list of organizations represented on th
4、is committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.Amendments issued since
5、 publicationAmd. No. Date CommentsEUROPEAN STANDARD EN 61161 NORME EUROPENNE EUROPISCHE NORM April 2007 CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassar
6、t 35, B - 1050 Brussels 2007 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 61161:2007 E ICS 17.140.50 Supersedes EN 61161:1994 + A1:1998English version Ultrasonics - Power measurement - Radiation force balances and performance r
7、equirements (IEC 61161:2006) Ultrasons - Mesurage de puissance - Balances de forces de rayonnement et exigences de fonctionnement (CEI 61161:2006) Ultraschall - Leistungsmessung - Schallfeldkraft-Waagen und Anforderungen an ihre Funktionseigenschaften (IEC 61161:2006) This European Standard was appr
8、oved by CENELEC on 2007-03-01. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nati
9、onal standards may be obtained on application to the Central Secretariat or to any CENELEC member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CENELEC member into its own languag
10、e and notified to the Central Secretariat has the same status as the official versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Cyprus, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia
11、, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. EN 61161:2007 2 Foreword The text of document 87/325/CDV, future edition 2 of IEC 61161, prepared by IEC TC 87, Ultrasonics, was submitted to the
12、 IEC-CENELEC parallel Unique Acceptance Procedure and was approved by CENELEC as EN 61161 on 2007-03-01. This European Standard supersedes EN 61161:1994 + A1:1998. The main significant changes are: the main body of the standard has been restricted to normative statements; informative statements on c
13、orresponding aspects of ultrasonic power measurement and radiation force balances have been collected in Annex A; Annexes A, D, E and F are new; more radiation force balance arrangements are dealt with. The new material relates particularly to power measurement of ultrasonic physiotherapy devices. T
14、he following dates were fixed: latest date by which the EN has to be implemented at national level by publication of an identical national standard or by endorsement (dop) 2007-12-01 latest date by which the national standards conflicting with the EN have to be withdrawn (dow) 2010-03-01 The followi
15、ng print types are used: requirements: roman type; notes: small roman type; words in bold in the text are defined in Clause 3. The numbers in square brackets refer to the Bibliography (after the annexes). Annex ZA has been added by CENELEC. _ Endorsement notice The text of the International Standard
16、 IEC 61161:2006 was approved by CENELEC as a European Standard without any modification. _ 3 EN 61161:2007 CONTENTS INTRODUCTION.5 1 Scope 6 2 Normative references .6 3 Terms and definitions .7 4 List of symbols .8 5 Requirements for radiation force balances 9 5.1 General .9 5.2 Target type9 5.3 Tar
17、get diameter .10 5.4 Balance / Force measuring system.10 5.5 System tank 10 5.6 Target support structures.10 5.7 Transducer positioning 10 5.8 Anti-streaming foils11 5.9 Transducer coupling 11 5.10 Calibration.11 6 Requirements for measuring conditions.11 6.1 Lateral target position11 6.2 Transducer
18、-target separation .11 6.3 Water 11 6.4 Water contact 11 6.5 Environmental conditions.12 6.6 Thermal drifts 12 7 Measurement uncertainty12 7.1 General .12 7.2 Balance system including target suspension.12 7.3 Linearity and resolution of the balance system .12 7.4 Extrapolation to the moment of switc
19、hing the ultrasonic transducer.13 7.5 Target imperfections13 7.6 Reflecting target geometry.13 7.7 Lateral absorbers in the case of reflecting target measurements.13 7.8 Target misalignment 13 7.9 Ultrasonic transducer misalignment13 7.10 Water temperature.13 7.11 Ultrasonic attenuation and acoustic
20、 streaming13 7.12 Foil properties .14 7.13 Finite target size14 7.14 Plane-wave assumption .14 7.15 Environmental influences.14 7.16 Excitation voltage measurement.14 7.17 Ultrasonic transducer temperature .14 7.18 Non-linearity14 7.19 Other sources14 EN 61161:2007 4 Annex A (informative) Additional
21、 information on various aspects of radiation force measurements16 Annex B (normative) Basic formulae.28 Annex C (informative) Other methods of ultrasonic power measurement .31 Annex D (informative) Propagation medium and degassing.32 Annex E (informative) Radiation force measurement with diverging u
22、ltrasonic beams37 Annex F (informative) Limitations associated with the balance arrangements 41 Annex ZA (normative) Normative references to international publications with their corresponding European publications49 Bibliography .46 Figure 1 Section through an absorbing target .15 Figure 2 Linearit
23、y check: balance readout as a function of the input quantity .15 Figure D.1 Example of dissolved oxygen concentration as a function of time for 200 ml of vacuum degassed water in a glass with liquid surface area of 34 cm2.34 Figure D.2 Dissolved oxygen concentration as a function of time for 2 g/l,
24、4 g/l and 6 g/l of sodium sulphite in de-mineralized water and for different surface areas and volumes of water 35 Figure E.1 Piston result (oscillating curve) for P/cF as a function of ka, with “peak“ approximation (unbroken line) and the central, half-way curve (broken line) representing the corre
25、ction factor corr. 38 Figure E.2 P/cF as a function of ka for four different pseudo-trapezoidal amplitude distributions, with = 0 (piston) (solid); = 0,1 (dash); = 0,25 (dot); = 0,6 (dash/dot).38 Figure E.3 Ratio of the radiation conductance G as obtained using a convex-conical reflecting target wit
26、h a cone half-angle of 45 to an absorbing target versus the value of ka for 11 different transducers to be used in physiotherapy and 3 different laboratories 2640 Figure F.1 Arrangement A, with absorbing (a) or reflecting (b) target.42 Figure F.2 Arrangement B, with convex-conical reflecting target4
27、2 Figure F.3 Arrangement B, with absorbing target 42 Figure F.4 Arrangement C, with absorbing target 43 Figure F.5 Arrangement E, with absorbing (a) or concave-conical reflecting (b) target .43 Figure F.6 Arrangement F, with convex-conical reflecting target43 Figure F.7 Arrangement F, with absorbing
28、 target 43 Table D.1 Water degassing methods 33 Table D.2 Conditions for degassing by boiling 34 Table F.1 Advantages and disadvantages of different arrangements .45 5 EN 61161:2007 INTRODUCTION A number of measuring methods exist for the determination of the total emitted power of ultrasonic transd
29、ucers (1, 2, 3, see also Annex C). The purpose of this International Standard is to establish standard methods of measurement of ultrasonic power in liquids in the lower megahertz frequency range based on the measurement of the radiation force using a gravimetric balance. The great advantage of radi
30、ation force measurements is that a value for the total radiated power is obtained without the need to integrate field data over the cross-section of the radiated sound beam. This standard identifies the sources of errors and describes a systematic step-by-step procedure to assess overall measurement
31、 uncertainty as well as the precautions that should be undertaken, and uncertainties that should be taken into account, while performing power measurements Basic safety requirements for ultrasonic physiotherapy devices are identified in IEC 60601-2-5 and make reference to IEC 61689, which specifies
32、the need for acoustic power measurements with an uncertainty better than 15 %. Considering the usual degradation of accuracy in the practical application of this standard, reference measurement methods need to be established with uncertainties better than 7 %. Ultrasonic diagnostic device declaratio
33、n requirements, including acoustic power, are specified in other IEC standards, as for example in IEC 61157. The measurement of acoustic power accurately, precisely and repeatably using a radiation force balance as defined in this standard is influenced by a number of practical problems. As a guide
34、to the user, additional information is provided in Annex A using the same section and clause numbering as the main body. EN 61161:2007 6 ULTRASONICS POWER MEASUREMENT RADIATION FORCE BALANCES AND PERFORMANCE REQUIREMENTS 1 Scope This International Standard specifies a method of determining the total
35、 emitted acoustic power of ultrasonic transducers based on the use of a radiation force balance; establishes general principles for the use of radiation force balances in which an obstacle (target) intercepts the sound field to be measured; establishes limitations of the radiation force method relat
36、ed to cavitation and temperature rise; establishes quantitative limitations of the radiation force method in relation to diverging and focused beams; provides information on assessment of overall measurement uncertainties. This International Standard is applicable to: the measurement of ultrasonic p
37、ower up to 1 W based on the use of a radiation force balance in the frequency range from 0,5 MHz to 25 MHz; the measurement of ultrasonic power up to 20 W based on the use of a radiation force balance in the frequency range 0,75 MHz to 5 MHz; the measurement of total ultrasonic power of transducers,
38、 preferably with well-collimated beams; the use of radiation force balances of the gravimetric type or force feedback type. NOTE The titles of all publications referred to in this Standard are listed in the Bibliography. 2 Normative references The following referenced documents are indispensable for
39、 the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. IEC 60050, International Electrotechnical Vocabulary (IEV) Chapter 801: Acoustics and Electroacoustics, C
40、hapter 802: Ultrasonics IEC 60854:1986, Methods of measuring the performance of ultrasonic pulse-echo diagnostic equipment IEC 60866:1987, Characteristics and calibration of hydrophones for operation in the frequency range 0,5 MHz to 15 MHz IEC 61101:1991, The absolute calibration of hydrophones usi
41、ng the planar scanning technique in the frequency range 0,5 MHz to 15 MHz 7 EN 61161:2007 IEC 61102:1991, Measurement and characterisation of ultrasonic fields using hydrophones in the frequency range 0,5 MHz to 15 MHz IEC 61689:1996, Ultrasonics Physiotherapy systems Performance requirements and me
42、thods of measurement in the frequency range 0,5 MHz to 5 MHz IEC 61846:1998, Ultrasonics Pressure pulse lithotripters Characteristics of fields 3 Terms and definitions For the purposes of this document, the following terms and definitions as well as the definitions of IEC 60050-801 and IEC 60050-802
43、 apply. 3.1 acoustic streaming bulk fluid motion initiated by a sound field 3.2 free field sound field in a homogeneous isotropic medium whose boundaries exert a negligible effect on the sound waves IEV 801-23-28, modified 3.3 output power time-average ultrasonic power emitted by an ultrasonic trans
44、ducer into an approximately free field under specified conditions in a specified medium, preferably water Symbol: P Unit: watt, W 3.4 radiation force acoustic radiation force time-average force acting on a body in a sound field and caused by the sound field, excluding the component due to acoustic s
45、treaming; or, more generally: time-average force (excluding the component due to acoustic streaming) in a sound field, appearing at the boundary surface between two media of different acoustic properties Symbol: F Unit: Newton, N EN 61161:2007 8 3.5 radiation pressure acoustic radiation pressure rad
46、iation force per unit area NOTE This term is widely used in the literature. However, strictly speaking, the radiation force per unit area is a tensor quantity 4 and it should be referred to as the acoustic radiation stress tensor when a strict scientific terminology is to be used. The integral quant
47、ity “acoustic radiation force“ is generally preferred in this International Standard. Whenever at some places the term “acoustic radiation pressure“ appears, it is to be understood as the negative value of the normal radiation stress in the direction of the field axis. Unit: Pascal, Pa 3.6 target de
48、vice specially designed to intercept substantially all of the ultrasonic field and to serve as the object which is acted upon by the radiation force 3.7 ultrasonic transducer device capable of converting electrical energy to mechanical energy within the ultrasonic frequency range and/or reciprocally
49、 of converting mechanical energy to electrical energy 3.8 radiation conductance ratio of the acoustic output power and the squared RMS transducer input voltage. It is used to characterize the electrical to acoustical transfer of ultrasonic transducers Symbol: G Unit: siemens, S 4 List of symbols a radius of a source ultrasonic transducer c speed of sound (usually in water) d geometrical focal length of a focused ultrasonic trans
