A fluid level sensor is disclosed having first and second vertically and horizontally nonoverlapping electrode plates for placing on a wall of a fluid container. Most preferably, the plates are also vertically spaced from each other. The capacitor plates are driven by a high frequency square wave. By forming nonoverlapping plates and driving them using a high frequency, the level of a fluid within the container, particularly viscous fluid, is more accurately detected. Control and detection circuitry is also disclosed to trigger an alarm if the fluid level drops below a critical level within the container.