Fluctuations of ultrasonic transducer vibration measurement quadrature interferometer for transducer vibration measurement

Langevin type transducers are being used by reason of the high transmitting power capability for various purposes. The peak-to-peak value of the transducer mechanical oscillation is in order of tens of the nanometers (for the resonant frequency and two ring transducer). Transducer vibration parameters depend considerably on excitation voltage and frequency. Beyond the resonant frequency some parasitic resonance frequencies are produced. Precise measurement of vibration with nanometer accuracy in the range of the ultrasonic frequencies can be done with using optical interferometry. Results show high distortion of the transducer displacement waveforms and poor amplitude stability.