Float switch is a type of level sensor, a device used to detect the level of liquid within a tank.
The switch may be used to control a pump, as an indicator, an alarm, or to control other devices.
One type of float switch uses a mercury switch inside a hinged float.
Another common type is a float that raises a rod to actuate a microswitch.
One pattern uses a reed switch mounted in a tube; a float, containing a magnet, surrounds the tube and is guided by it.
When the float raises the magnet to the reed switch, it closes.
Several reeds can be mounted in the tube for different level indications by one assembly.
