Development and test of conductivity sensor for monitoring groundwater resources to optimize the water management in Smart City environments

Abstract

The main aim of smart cities is achieving sustainable resources. In order to make a correct use of resources, an accurate monitoring and management of them are needed. In some places, like underground aquifers, the access for monitoring can be hard therefore the use of sensors can be a good solution. The groundwater is very important as a water resource, just in USA, aquifers suppose the water resource for 50% of population. However, its importance aquifers are endangered due to the contamination. One of the most important parameters to monitor in groundwater is the salinity. High salinity level indicates groundwater salinization. In this paper we present a specific sensor for groundwater salinization monitoring. The sensor is able to measure the electric conductivity of water, i.e., higher electric conductivity means higher water salinization. The sensor, which is composed of two copper coils, measures the alterations in magnetic fields due to the presence of electric charges in water. Different salinities in water generate different alterations. Our sensor is undergone to several tests performed in order to obtain a conductivity sensor with enough accuracy. First, several prototypes are tested and are compared with the purpose of choosing the best coils combination. When the best prototype is selected, it is calibrated using up to 30 different samples. Our Conductivity sensor presents an operational range from 0.585 mS/cm to 73.8 mS/cm, which is wide enough to cover the needs. With this work, we have demonstrated that it is feasible of measuring water conductivity using solenoids coils and its application for groundwater monitoring.