Revolutionize Monitoring: Introducing Our Digital Tape Extensometer

The Digital Tape Extensometer is a portable device used for measuring displacement between pairs of eyebolts. These may be installed on a structure or in an excavation such as a tunnel or shaft. The Digital Tape Extensometer unit comprises a stainless steel measuring tape with equally spaced precision punched holes. The tape winds onto a reel, which incorporates a tape tensioning device and a digital LCD readout.

​For quick and accurate measurement of relative distances between pairs of reference points on the surfaces of structures including radial movements and convergence of tunnels, shafts, linings and caverns, deformation of excavations in underground caverns and displacements of retaining walls, cuttings, bridge piers, arches.

Product Features

  • Measuring range of up to 30m
  • Digital LCD readout giving precise measurement
  • Stainless steel measuring tape
  • Optical tension indicator

Product Benefits

  • Compact, portable and lightweight
  • Accurate and robust
  • Simple, reliable and easy to read
  • Repeatable measurements using the optical tape tension indicator
  • Can be operated by one person
  • Can read multiple arrays using a single instrument


The instrument only requires one person to operate. The body of the extensometer has a hook connector that connects to the first eyebolt. An identical hook on the free end of the tape connects on to the opposing eye bolt.

The user then tensions the instrument and record the readings from the digital LCD display. The measurements are not absolute, but relative to the previous measurement. This provides an accurate record of displacement over time.


Typical applications of Digital Tape Extensometers include:

  • Radial movements and convergence of tunnels, shafts, linings and caverns
  • Displacement of retaining walls, cuttings, bridge piers, arches and abutments
  • Monitoring and control of construction by the sprayed, shotcrete tunnelling method
  • Monitoring of deformation of embankment dam crests.

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