The Vibrating Fork Level Switch is a level limit switch used to detect whether or not the level of water in the water or the oil in a vessel has reached a set level. The fork of the switch is continuously excited at its natural resonance frequency. When the level of liquid reaches the fork, the frequency of oscillation changes. This is detected by the device which triggers a relay. The Vibrating Fork Level Switch allows continuous monitoring and is suitable for overspill-protection setups.