Passive and wireless displacement measuring device using parallel sensors

摘要

A system that remotely measures displacement between two objects. A passive sensor is affixed to each object, such that the sensors are substantially parallel. Each sensor has a permeable rod, a surrounding coil, and a tuning capacitor, and have substantially the same resonant frequency. When an interrogating device is placed near the sensors, the frequency responses of the sensors indicates their relative displacement and thus the displacement between the objects.