Fixed extensometer is a single rod extensometer, usually defined as device placed in embankment fill or inside borehole for monitoring of settlement or heave between two points without use of a removable probe.
Either the Settlement Platform and the Tell-Tale extensometer are based on a riser settlement rod which is respectively connected to a plate buried at the embankment foundation level or grouted inside borehole as a deep benchmark in a firm soil.
Optical levelling measurements to the top of the riser rod provide precise monitoring. Electrical transducer can be used for remote readings without the need of survey crew.
