A Novel Method to Measure Acoustic Power of FocusingTransducer with Spherical Surface Based on Self-Reciprocity Theorem

Abstract

A novel method to measure acoustic power of focusing transducer basedon the self-reciprocity theorem of convergent spherical acoustic wave isproposed. The performance of this reciprocity method is compared withthat of the radiation force balance (RFB) method and the admittancecircle method. The average deviations of the reciprocity method fromRFB in measurements of the acoustic power and the radiation conductancefor a focusing transducer of 1.525 MHz are 7.5% and 3.6% respectively,and for another focusing transducer of 5.27 MHz, they are 1.7% and1.1%. The measured radiation conductance deviation by the reciprocitymethod from the admittance circle method for the focusing transducer of1.525 MHz is 7.9%. It presents encouraging results even in measuringlow acoustic power level. The overall uncertainty of acoustic powermeasurement using the method is evaluated below 10%, and it has manyadvantages such as high signal-to-noise ratio, good stability and lessinterference of bubbles and environment.