This sensor is designed to monitor the filling status of concrete in the formwork. 
By attaching the sensor to any location to be monitored and connecting it to a measuring instrument, the filling status can be monitored in real time. 
This sensor is particularly useful for quality control of construction work in confined spaces where it is difficult to check the filling status by compaction or visual observation, such as the flowability of high-fluidity fresh concrete in structures with high-density reinforcement.