SMART Contractometer


Based on MDT’s proven and popular MPBX, the SMART Contractometer uses a collapsible structure to allow the measurement of convergence. Like our MPBX, the Contractometer is a flexible six-point fully recessable unit with our patented electronic readout head. The sensor and head are small enough to be recessed into a 50 mm (2 in) diameter borehole for easy installation.

In situations like backfill and shotcrete pillar monitoring, special 102 mm (4 inch) diameter shear washers are available to ensure that full transfer of convergence to the Contractometer is assured. The leadwires are enclosed in a polypropylene cover, which can be immersed in backfill or shotcreted over for protection.

Contact our engineering staff for customized design or installation services.


  • 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)

    Features and Benefits

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


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