A low-cost capacitive sensor for water level monitoring in large-scale storage tanks

Water-level sensors are indispensable for monitoring the level of water in storage tanks, which are used in drinking water distribution networks. In this paper, a long-range capacitive-type water-level sensor is presented. The proposed sensor is constructed using widely-available multilayer tubes, which are used for building drinking water systems. Thus, both the manufacturing cost of the sensor and the cost of the associated electronic circuits, which are used for interfacing the sensor to a digital data-acquisition unit, are low. The performance of the proposed sensor has been evaluated in a water storage tank of a city-scale water distribution network. The experimental results indicate that the accuracy of the proposed experimental prototype sensor is equivalent to that of a commercially available ultrasound water level sensor, while, additionally, its manufacturing cost is significantly lower.