The Model 4200 Displacement Detector System is an Early Warning System. The displacement detector consists of up to 6 displacement sensor switches. The detector control unit is attached to a post. The sensors’ switch ends are mounted on stable ground and the other end is attached and turns on an audible/visual alarm to the moving section. The system switches when a pre-set displacement is exceeded or the cable is broken. The Model 4200 controller allows up to six sensors to be monitored continually.


Measurement of displacements in:

  • Open cut mining
  • Deep excavations
  • Land fill subsidence
  • Embankment
  • Cliff stability
  • Structure stability


  • Fail safe operation
  • Waterproof enclosure
  • Sensor condition indicator
  • System integrity test facility
  • Battery condition indicator
  • Inexpensive sensors
  • Controller can be re-located
  • Small volume of equipment

Specifications of the Model 4200 Displacement Detector System

  • Displacement limit range: 1 – 90 mm
  • The alarm controller suits up to 6 sensors
  • Steel posts as the surface sensor anchors
  • Audible and visual alarm signal comprises a 12V double strike xenon beacon and a 120dB pulsed tone audible siren
  • Dimension (head frame): 380 x 600 x 210 mm
  • Dimension (sensor): 25 mm x 510 mm long
  • Dimension (audible/visual alarm): 390 x 220 x 540 mm
  • Weight (head frame): 13.7 kg
  • Weight (sensor) 0.44 kg
  • Weight (audible/visual alarm): 13 kg