MDT Borehole Extensometer (MPBX) Smart Contractometer

Product Information

The SMART Contractometer utilizes a collapsible structure to allow it to measure convergence. It has been used in applications like shotcrete pillars, backfill convergence, sill pillar squeeze, and micropile loading. Like the MPBX, the Contractometer is a flexible, six-point fully recessable unit with an integrated electronic readout head. The sensor and head are small enough to be recessed into a 50 mm (2 in) diameter borehole, and the instruments are easy to install. 

Product Features

  • Length: up to 50 m
  • Diameter: 33 mm
  • Weight: 0.5 kg/m
  • Borehole diameter: 50 mm minimum
  • Transducer: linear potentiometers
  • Stroke: 63.5, 127, and 190.5 mm
  • Linearity: +/- 2% (1% available upon request)

Product Benefits

  • Can be monitored WIRELESSLY!
  • User specified anchor locations
  • Compact design
  • No assembly required
  • Inexpensive yet ruggedly designed for field use

Typical Applications Include:

  • Compression in shotcrete pillars
  • Convergence in backfill
  • Squeeze in sill pillars
  • Compression in micro-piles
  • Mine shaft convergence
  • Tunnel convergence



MDT Borehole Extensometer MPBX Data Sheet