Float Water Level Sensor (Float Switch)

A float switch is a mechanical switch that physically senses whether the liquid in a container such as a water tank or aquarium has reached a certain height. The magnet inside the float part, which moves with the buoyancy of the water, triggers the magnetic switch (reed relay) on the fixed body to open or close the circuit. Since the electrical contacts are completely insulated inside the plastic housing, it does not cause corrosion (oxidation) problems like conventional analog water sensors. It can be easily read with the digital pins of Arduino and ESP series cards and can be safely used in water tank fullness alarms, automatic water pump control and hydroponic agriculture systems.