Time synchronization method of wireless distributed sensor node and its application for real-time dust monitoring

In this study, we aim to conduct real-time sensing of indoor dust concentration distribution to mitigate the airborne transmission of coronaviruses. Airborne infection, facilitated by viruses present in particulate matter, emphasizes the importance of monitoring dust concentration as an indicator of virus spread. Our approach involves the implementation of a time-synchronized wireless sensor network for real-time sensing of dust concentration distribution. The time-synchronized wireless sensor network relies on a proposed time-synchronization algorithm, ensuring a time error of less than ± 1.27 ms. This precision enables the measurement of even fast-moving dust particles. To validate the feasibility of the wireless time-synchronized sensor network, we utilized a dust ejector (air cannon) and positioned time-synchronized sensors in a row. Dust particles released from the ejector passed through each time-synchronized sensor terminal. Simultaneously, a video recording (60 frames) was conducted, and the measured times of the time-synchronized sensor terminals were compared with the lap times of the video. The results of this comparison revealed identical lap times between the time-synchronized sensor data and the video, affirming the successful operation of the time-synchronized wireless distributed sensor node as designed.