A float switch is comprised of a permanent magnet to ensure it moves along with the liquid level on a guide tube and provides accurate level readings. The guide tube is fitted with a reed contact (inert gas contact) and is energized by the approach of the float magnet. By using a magnet and reed contact, the operation of the float switch is non-contact, free from wear and needs no power supply. The contacts are potential-free. Magnetic float switches are also available with multiple switch points.
The switch functions always refer to a rising liquid level: SPDT or change-over contact.
Using a float for two switch points creates a bi-stable switch operation, meaning that the switching status remains available when the filling level continues to rise above or drop below the switch point.
A float switch is simple to mount and maintenance-free, providing a cost-effective solution.