Liquid-Level Sensing Utilizing Evanescent Waves Created inPiezoelectric Vibrators Operating in Trapped-Energy Modes

毫米级或更小的液位测量已成为生物和化学领域的重要课题。作为众所周知的脉冲回波方法的替代方案，我们已经提出了一种新的技术，该技术采用了压电厚度振动器，该振动器在捕获能量模式下工作，用于检测液位的小尺度变化。通过实验和等效网络模型的理论分析，观察到了电导G随液位的变化规律，证实了传感装置的可行性。

The measurement of liquid level on the millimeter scale or less has become an important subject in biological and chemical fields. As an alternative to the well -known pulse-echo method, we have presented a new technique that employs a piezoelectric thickness vibrator operating in a trapped-energy mode for detecting a small-scale variation in liquid level. The variation in the electric conductance G with the liquid level has been observed by experiments and also by theoretical analysis using an equivalent-network model, and the feasibility of the sensing device is confirmed.