Vibrating Fork Level switches utilize a piezoelectric-driven tuning fork that exhibits a large change in resonant frequency when immersed into a liquid or bulk solid process. A "smart" microprocesso-based electronic unit keeps the sensor in a resonant state as it changes from dry to wet or wet to dry. An important feature of this switch is that its resonant frequency is not significantly affected by coating on the fork until the space between the forks is bridged. Applications include redundant high/low process levels without concern for parameters, such as specific gravity, dielectric constant or mounting position of the sensor.