Measurement of a piezoelectric transducer´s mechanical resonant frequency based on residual vibration signals

The paper presents a novel measurement method for a piezoelectric transducer mechanical resonant frequency. A transducer natural frequency is obtained through analyzing residual vibration signals spectrum based on the Morlet wavelet transform, and subsequently the transducer mechanical resonant frequency is calculated against the relationship of the natural frequency and the mechanical resonant frequency, i.e. a novel scheme being termed as twice exciting/sampling in this work. Experiments carried on a transducer (the mechanical resonant frequency was 19.72 kHz) have shown that the accuracy was up to 0.18% under the condition of the exciting frequency being set manually within 15~29 kHz. The constructed measurement system has advantages of simple structure and low cost.