A device used to detect the level of liquid within a tank. In a sump pump (see SUMP DRAINAGE SYSTEM) it is used to detect the rising level of liquid in the tank. When the liquid reaches a specified level it turns the electrical pump on, which then pumps liquid out until it has been substantially reduced, at which point the pump is switched off again. Float switches are often adjustable.
EXAMPLE:
The float switch kept the tank from overflowing.
