IEC 62555:2013 establishes general principles relevant to HITU fields for the use of radiation force balances in which an obstacle (target) intercepts the sound field to be measured; specifies a calorimetric method of determining the total emitted acoustic power of ultrasonic transducers based on the measurement of thermal expansion of a fluid-filled target; specifies requirements related to the statement of electrical power characteristics of ultrasonic transducers; provides guidance related to the avoidance of acoustic cavitation during measurement; provides guidance related to the measurement of HITU transducers of different construction and geometry, including collimated, diverging and convergent transducers, and multi-element transducers; provides guidance on the choice of the most appropriate measurement method; and provides information on assessment of overall measurement uncertainties. This International Standard is applicable to the measurement of ultrasonic power generated by HITU equipment up to 500 W in the frequency range from 0,5 MHz to 5 MHz. HITU equipment may generate convergent, collimated or divergent fields. For frequencies less than 500 kHz, no validations exist and the user should assess the uncertainties of the power measurement and measurement system at the frequencies of operation. This International Standard does not apply to ultrasound equipment used for physiotherapy, for lithotripsy for general pain relief.<\/p>\n
| PDF Pages<\/th>\n | PDF Title<\/th>\n<\/tr>\n | ||||||
|---|---|---|---|---|---|---|---|
| 6<\/td>\n | English CONTENTS <\/td>\n<\/tr>\n | ||||||
| 9<\/td>\n | INTRODUCTION <\/td>\n<\/tr>\n | ||||||
| 10<\/td>\n | 1 Scope 2 Normative references 3 Terms and definitions <\/td>\n<\/tr>\n | ||||||
| 13<\/td>\n | 4 List of symbols <\/td>\n<\/tr>\n | ||||||
| 14<\/td>\n | 5 Power measurement for HITU equipment <\/td>\n<\/tr>\n | ||||||
| 15<\/td>\n | 6 Radiation force on a target 6.1 General <\/td>\n<\/tr>\n | ||||||
| 16<\/td>\n | 6.2 Requirements for equipment 6.2.1 Target type <\/td>\n<\/tr>\n | ||||||
| 17<\/td>\n | 6.2.2 Target diameter 6.2.3 Balance \/ force measuring system 6.2.4 System tank 6.2.5 Target support structures 6.2.6 Transducer positioning 6.2.7 Anti-streaming foils <\/td>\n<\/tr>\n | ||||||
| 18<\/td>\n | 6.2.8 Transducer coupling 6.2.9 Calibration and stability 6.3 Requirements for measuring conditions 6.3.1 Lateral target position 6.3.2 Transducer\/target separation 6.3.3 Water <\/td>\n<\/tr>\n | ||||||
| 19<\/td>\n | 6.3.4 Water contact 6.3.5 Environmental conditions 6.3.6 Thermal drifts 6.4 Measurement uncertainty 6.4.1 General 6.4.2 Non-planar ultrasound field 6.4.3 Balance system with target suspension 6.4.4 Linearity and resolution of the balance system <\/td>\n<\/tr>\n | ||||||
| 20<\/td>\n | 6.4.5 Extrapolation to the moment of switching the ultrasonic transducer 6.4.6 Target imperfections 6.4.7 Reflecting target geometry 6.4.8 Lateral absorbers in the case of reflecting target measurements 6.4.9 Target misalignment 6.4.10 Ultrasonic transducer misalignment 6.4.11 Water temperature <\/td>\n<\/tr>\n | ||||||
| 21<\/td>\n | 6.4.12 Ultrasonic attenuation and acoustic streaming 6.4.13 Foil properties 6.4.14 Finite target size 6.4.15 Environmental influences 6.4.16 Excitation voltage measurement 6.4.17 Ultrasonic transducer temperature 6.4.18 Nonlinearity 6.4.19 Other sources <\/td>\n<\/tr>\n | ||||||
| 22<\/td>\n | 6.5 Calculation of output power 7 Buoyancy change of a target 7.1 General Figures Figure\u00a01 \u2013 Linearity check: balance readout as a function of the input quantity <\/td>\n<\/tr>\n | ||||||
| 23<\/td>\n | 7.2 Requirements for equipment 7.2.1 Target type <\/td>\n<\/tr>\n | ||||||
| 24<\/td>\n | 7.2.2 Entry window diameter 7.2.3 Balance \/ force measuring system 7.2.4 System tank 7.2.5 Target support structures 7.2.6 Transducer positioning 7.2.7 Anti-streaming foils <\/td>\n<\/tr>\n | ||||||
| 25<\/td>\n | 7.2.8 Transducer coupling 7.2.9 Calibration 7.3 Requirements for measuring conditions 7.3.1 Lateral target position 7.3.2 Transducer\/Target separation 7.3.3 Water <\/td>\n<\/tr>\n | ||||||
| 26<\/td>\n | 7.3.4 Water contact 7.3.5 Environmental conditions 7.3.6 Thermal drifts 7.4 Measurement uncertainty 7.4.1 General 7.4.2 Buoyancy sensitivity 7.4.3 Non-planar ultrasound field 7.4.4 Balance system including target suspension 7.4.5 Linearity and resolution of the balance system <\/td>\n<\/tr>\n | ||||||
| 27<\/td>\n | 7.4.6 Curve-fitting and extrapolation 7.4.7 Water temperature 7.4.8 Ultrasonic attenuation and acoustic streaming 7.4.9 Foil properties 7.4.10 Finite target size 7.4.11 Environmental influences 7.4.12 Excitation voltage measurement <\/td>\n<\/tr>\n | ||||||
| 28<\/td>\n | 7.4.13 Ultrasonic transducer temperature 7.4.14 Nonlinearity 7.4.15 Other sources 7.5 Calculation of output power 8 Electrical characteristics 8.1 Electrical impedance 8.2 Radiation conductance <\/td>\n<\/tr>\n | ||||||
| 29<\/td>\n | 8.3 Efficiency <\/td>\n<\/tr>\n | ||||||
| 30<\/td>\n | Annex A (informative) Other measurement methods <\/td>\n<\/tr>\n | ||||||
| 31<\/td>\n | Annex B (informative) Target size <\/td>\n<\/tr>\n | ||||||
| 33<\/td>\n | Annex C (informative) Formulae for radiation force <\/td>\n<\/tr>\n | ||||||
| 35<\/td>\n | Figure\u00a0C.1 \u2013 Correction factor of plane wave for the acoustic field ofa circular plane piston ultrasonic transducer as a function of the productof the circular wavenumber and transducer radius <\/td>\n<\/tr>\n | ||||||
| 38<\/td>\n | Annex D (informative) Expansion method Figure\u00a0D.1 \u2013 Schematic diagram of an expansion target. <\/td>\n<\/tr>\n | ||||||
| 39<\/td>\n | Figure\u00a0D.2 \u2013 Example of weight vs time sequence <\/td>\n<\/tr>\n | ||||||
| 41<\/td>\n | Table\u00a0D.1 \u2013 Selected properties of Acros\u00ae Organics castor oilin the range 10\u00a0\u00b0C to 60\u00a0\u00b0C <\/td>\n<\/tr>\n | ||||||
| 42<\/td>\n | Figure\u00a0D.3 \u2013 Time history of the apparent mass of the castor oil targetat different frequencies following an insonation of approximately 1\u00a0Wacoustic power for a period of 10\u00a0s <\/td>\n<\/tr>\n | ||||||
| 43<\/td>\n | Table\u00a0D.2 \u2013 Absorption coefficient of castor oil as a function of temperature <\/td>\n<\/tr>\n | ||||||
| 44<\/td>\n | Annex E (informative) Influence of attenuation and acoustic streamingon determining incident and output powers <\/td>\n<\/tr>\n | ||||||
| 47<\/td>\n | Annex F (informative) Avoidance of cavitation <\/td>\n<\/tr>\n | ||||||
| 48<\/td>\n | Annex G (informative) Transducer efficiency <\/td>\n<\/tr>\n | ||||||
| 54<\/td>\n | Figure\u00a0G.1 \u2013 Electrical voltage source under different loading conditions Figure\u00a0G.2 \u2013 Electrical voltage source and electrical matching networkand transducer equivalent circuit <\/td>\n<\/tr>\n | ||||||
| 55<\/td>\n | Figure\u00a0G.3 \u2013 Diagram illustrating electrical loss. <\/td>\n<\/tr>\n | ||||||
| 56<\/td>\n | Bibliography <\/td>\n<\/tr>\n<\/table>\n","protected":false},"excerpt":{"rendered":" Ultrasonics. Power measurement. High intensity therapeutic ultrasound (HITU) transducers and systems<\/b><\/p>\n |