A low-power IoT architecture for the monitoring of chemical emissions

In this work, a low-power IoT architecture for the monitoring of chemical emissions is presented. This system is expected to be employed to set up monitoring infrastructures in industrial plants or public buildings. The proposed system has been designed to embed different sensors. In particular, each sensor node manages a humidity sensor and an array of temperature and electrochemical gas sensors for the detection of carbon monoxide (CO), nitrogen oxides (NOx), and oxygen (O2). Moreover, it exploits some dedicated processing algorithms to mitigate the dependence of the sensor response on temperature. The sensor node has been designed to minimise power consumption as much as possible, and it is provided with LoRa LPWAN connectivity, which allows for wide-area data transmission. Tests carried out in urban areas proved that a 3 km communication range is achievable in noisy environments. A network architecture and a data acquisition and management structure are then described. A multilayer modular topology that combines the features of LoRa technology with shorter and larger range telecommunication channels in order to develop an IoT framework that can be customised according to the physical and technical features of the deployment scenario.