The Geosense® Vibrating Wire Settlement Profiler is used for the measurement of subsurface settlement.
Working principle: A vibrating wire sensor is located within a probe that can be pulled through a buried pipe or borehole. The sensor is connected via a liquid-filled tube mounted on a reel which is mounted horizontally at the reservoir location on stable ground. The reel is free to turn as the probe is pulled through the pipe or borehole.
The sensor measures the hydraulic head of liquid between the sensor and the reservoir locations.