Water Conductivity Sensor based on Coils to Detect Illegal Dumpings in Smart Cities

Illegal dumpings in sewerage can cause problems in wastewater treatment plants, so it may become an environmental problem. In this paper, we propose a system for detecting these illegal dumpings. We use conductivity sensors for detecting a change in the conductivity of water because this change may appear due to a dump. The system is based on two coils. One of the coils is powered by a sinus-wave and the other coil is induced. To prevent damage from water in the copper we encapsulate the coils in a PVC tube. These coils are connected to a Flyport in order to send the values and generate alarms. We tested the prototype with different configurations of coils with encapsulation of 3 and 1 mm. When the encapsulation is of 3 mm, we do not observe differences in the induced voltage. The prototype selected has a difference of 4.10 Volts between the samples 0 and 40 g/l of the table salt. In the verification test this prototype has a relative error of 2.54%.