The EDS-91 measures settlement or heave in foundations, embankments, fills, excavations etc. This magnetic settlement recorder is accurate, robust, light weight and convenient to use.

The system consists of an access tube, magnet assemblies and a portable magnetic probe with a reed switch. The probe is inserted inside the access tube installed with magnet assemblies at various depths, to detect the change in position of the magnet assemblies due to vertical soil movement. Magnet assemblies suitable for the inclinometer casing are also available. A similar system for monitoring horizontal displacement in embankments is available with a pull cable reel and dead end pulley assembly.

  • Datum magnet: for reference
  • Spider magnet with 6 leaves: for boreholes
  • Spider magnet with 3 leaves: for boreholes; can also be pushed in by a rod.
  • Plate magnet: for fills & embankments.

Compare Our Products

Instrument Name

Magnetic extensometer

Sensor Type



Available with plate and spider magnets to suit different applications and Magnetic probe for taking readings


Horizontal and vertical movement in borehole as well as embankments and fills




30, 50, 100, 150, 200, 300 m; 50, 100, 150, 300, 500 ft (magnetic probe)

Key Testing / Calibration

Measurement accuracy is verified

Key Feature/Advantage

Can be used vertically and horizontally, as well as in borehole and fills

Protection (Waterproofing)


Dimension (mm)


Other Extensometer Products


Soil Extensometer


Rock Bolt Extensometer

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