Extensometer

Magnetic extensometers are installed in areas of soft ground to monitor the scale and rate of deformation under embankments, roads or structures during the initial construction phase of the project. The access casing is installed vertically in the borehole and grouted in place, where a datum magnet is installed at the base of the hole. Spider magnets that grip the sides of the hole are then attached to the casing at different levels, which allows settlement to be monitored at different depth intervals within the soft ground, where monthly readings are undertaken using a reed switch probe.  An automatic system is also available.