The EDS-92 soil extensometer is used for monitoring displacement between two surfaces that may shift with respect to each other. It is widely used for monitoring of soil and rock movement in embankments and dams.
 
The system contains a specially mounted model EDE-VXX vibrating wire displacement sensor, installed inside the protective tubing, fixed between two anchor beams with connecting rods. Any change in the relative position between the anchor beams represents deformation taking place and is measured by the displacement transducer.
 
The extensometer system is supplied with different gage lengths (gage length is the distance between two anchors).
A number of extensometer units can also be connected in series to measure incremental displacements over large distances. Movement of relative position between two anchor channels at the ends of the soil extensometer is representative of mass movement.