EDS-91V/H magnetic extensometer is used to measure vertical settlement or lateral movement depending on the application. Settlement or heave at various levels within a soil mass may be assessed by monitoring location of magnetic targets which have been positioned over a near-vertical access tube.
 
The magnetic extensometer system has been designed to measure settlement or heave of soft ground under the influence of loading or unloading due to construction of embankments, fills, buildings, and structures.