Inductive Sensors

Inductive Contactless Distance measurement
Remote measurement of distance, position or movements of metal objects like wires or surfaces can be realized with RF magnetic fields.

• A very sensitive and fast position detector for thin copper-wires (0.1 mm) has been constructed yet. Movements in two directions as small as microns are converted to two analog signals with a bandwidth of DC- 20 kHz. The sensor does not induce current in the wire so the terminations and the length of it are of no importance.
  This detector can be used too for monitoring movements of small metal objects from a distance of 10 times its size.
  An LC-circuit with smaller dimensions can be sensed from a larger distance.
  
  At this moment the detector is in use for a medical application where the movements of organs is watched.
  
  

• A simple metal detector integrated in a label detectionsystem has been designed for Nedap. Wire-loops inside the EAS-panels are used for detecting shielding bags. Potential shoplifters who try to hack the labeldetection with shielding bags will be guarded from entry.

Parametric Measurement
Remote measurement of environmental parameters via the resonance frequency of an isolated LC-circuit has been demonstrated successfully.

Measurement of temperature is possible in separate places outside the range of optical IR sensors, and with temperatures too high for wireless semiconductor sensors or data loggers. This Distant Temperature Sensor has a useful range of -50 till +200 degrees.