A LoRaWAN Carbon Monoxide Measurement System With Low-Power Sensor Triggering for the Monitoring of Domestic and Industrial Boilers

Gases emitted by domestic and industrial boilers significantly contribute to the overall pollution levels of urban environments. Among these gases, carbon monoxide (CO) represents a marker of the efficiency of the combustion processes, and the monitoring of its emissions, even if often neglected, is crucial to improve energy efficiency and environmental safety within a smart city context. This article aims at describing a real-time, remote system for the monitoring of CO emissions of domestic and industrial boilers based on the use of a low-power long-range wide-area network (LoRaWAN) sensor node. In particular, the proposed solution is based on an ad hoc front-end circuit acting as a power-gating system for the rest of the sensor node, exploiting the output of the CO sensor as a trigger to activate the data acquisition and transmission module. Such a solution allows to notably increase the lifetime of the node, allowing its powering using rechargeable Li-ion batteries. Tests were performed on a real boiler in order to demonstrate the validity of the proposed solution. Power consumption of the sensor node was experimentally measured: theoretical analysis demonstrated an ideal lifetime for the sensor node up to two and half years.