Description of the float switch
A float with a permanent magnet moves reliably along with the liquid level on a guide tube. Within the guide tube is fitted a reed contact (inert gas contact), which is energised, through the non-magnetic walls of the float and guide tube, by the approach of the float magnet.
By using a magnet and reed contact the switching operation 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: normally open, normally closed or change-over contact.
Through the use of a float for a max. of 2 switch points a bistable switch operation can be achieved, meaning that the switching status also remains available, when the filling level continues to rise above or drop below the switch point.
The float switch is simple to mount and maintenance-free, so the costs of mounting, commissioning and operation are low.
Applications of the float switch
- Level measurement for almost all liquid media
- Pump and level control and monitoring for distinct filling levels
- Chemical, petrochemical, natural gas, offshore, shipbuilding, machine building, power generating equipment, power plants
- Process water and drinking water treatment, food and beverage industry
Special features of the float switch
- Large range of application due to the simple, proven functional principle
- For harsh operating conditions, long service life
- Operating limits:
- Operating temperature: T = -196 ... +350 °C
- Operating pressure: P = Vacuum to 40 bar
- Limit density: ρ ≥ 300 kg/m3
- Wide variety of different electrical connections, process connections and materials
- Explosion-protected versions