Abstract:

According to the expression of ultrasonic power based on the series resonant equivalent circuits, a method to measure the radiation conductance of standard ultrasonic transducer with a 4192A impedance analyzer is presented. The radiation conductance measured by the electrical method is then compared with that obtained by the national primary standard equipment for milliwatt ultrasonic power based on the radiation pressure method. The results indicate that the errors of radiation conductance of quartz-crystal, standard transducers with the nominal frequencies of 2. 5 and 5.0 MHz are respectively kept at 0. 35% and 2. 11% , that the en＇or of uhrasonie power of transducers is not greater than 3% when the error of voltmeter is not greater than 1%. Moreover, it is found from experimental results that the proposed method with simplicity and reliability can not only test the standard transducers whose ultrasonic powers are measured by means of the radiation pressure method but also act as a new measurement standard.

Key words: standard transducer, radiation conductance, ultrasonic power