The water level sensor is a simple and practical measurement module that works on the principle of changing resistance depending on the surface of the parallel conductive lines in contact with water. The more the sensor sinks into the water, the higher the conductivity, and therefore the higher the analog voltage output. It can be easily read through the analog (ADC) pins of Arduino and ESP series boards to determine the depth or presence of water. Since conductive lines may be subjected to corrosion (oxidation) over time when exposed to continuous DC current in water, it is recommended to make periodic measurements rather than leaving them in water continuously. It is frequently used in projects such as aquarium overflow alarms, pot bottom fullness warning and mini water tank level control.
