In-situ Calibration of Networked Air-Quality Sensor Nodes

Fixed monitoring stations are mostly used for air quality monitoring. Unfortunately, they are very expensive both in terms of initial investment and maintenance. Low-cost air quality sensors have emerged as an alternative for measuring basic air quality parameters. They are based on technologies that allow for real-time measurements. However, their use poses some challenges, such as accuracy and longterm stability. The accuracy of these low-cost sensors can be difficult to guarantee as they are often in harsh environments and are more susceptible to environmental impacts than high-end measurement devices. Periodic calibration of sensors has proven to be an effective approach for improving the accuracy of low-cost sensor data and maintaining its reliability when used in sensor networks for long-term monitoring. This article explores approaches to calibrate low-cost sensors used in wireless network applications to measure fine particulate matter concentrations. Some research challenges and directions for future research are presented.