​Multipoint borehole extensometers (MPBX) enable the monitoring of relative movements between a groutable anchor down a borehole and a reference head at the surface as a complete displacement monitoring system.

Sisgeo multipoint extensometers monitor measurement ranges up to 100mm (3.9”) or 200mm (7.9”) of up to 7points/ anchors, dependent upon the type of measurement rod and reference head used. Multipoint rod extensometers deployed in tunnelling, deep excavations, foundations and dam’s projects provide precise monitoring of displacement and settlement.

Product Features

  • Monitor up to seven points/ anchors
  • Antifriction nylon sleeve
  • Compatible with vibrating wire or 4-20mA displacement transducers
  • Measurement ranges up to 100mm (3.9”) or 200mm (7.9”)

Product Benefits

  • Available with fiberglass or stainless-steel rods
  • Can be configured specifically depending on application
  • Manual readings via calipers or automated readings via transducers
  • Pre-assembled, reducing installation costs

MPBX Operation

Anchors are fixed at a desired depth and attached to a measuring rod encased in a nylon tube for free movement in soil. Movements in this measuring rod can then me manually monitored with a caliper for precision readings at the surface.

Additionally, displacement transducers (vibrating wire or 4-20mA) can be attached to the reference head for automated and remote monitoring via a readout or datalogger.


Typical applications of the Multipoint Borehole Extensometer include:

  • Tunnelling
  • Mining
  • Deep excavations
  • Dam construction and monitoring
  • Displacement monitoring
  • Settlement monitoring
  • Rock displacement
  • Embankment monitoring

Geomotion offer installation and monitoring services to support this system. For more information please email info@geomotion.com.au or contact any of our locations.