By means of float with magnetic field and reed switches. One or more reed switches are placed at a specific height inside a guide tube. The changes in liquid level modify the float position in this guide tube, so that when it reaches the switch position, it changes its status, providing an output signal for level detection. Applications: • Pumps start-stop • Control of industrial processes and dosing tanks • Storage for food and beverage industry • Level control in shipping industry • Chemical and textile industry