The Loop Powered VF30 utilizes a piezoelectric driven tuning fork that exhibits a large change in resonant frequency when immersed in any liquid. A “smart” microprocessor-based electronic unit keeps the sensor in a resonant state as it changes from dry to wet or wet to dry. The resonant frequency is continuously monitored for changes created by a wet or dry sensor and an alarm is provided via an 8 or 16 ma dc signal. An important feature of the Vector is that its resonant frequency is not significantly affected by coating on the fork until the space between the forks is bridged. Vector’s ability to identify true liquid level in viscous, coating or aerated liquid is unparalleled. The self-test option checks for fault conditions such as sensor failure and excessive product build up on the sensor. Applications include redundant high/low liquid level without concern for parameters such as specific gravity, dielectric constant or mounting position of the sensor.