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Inductance proximity sensor

  1. Dec 11, 2014 #1

    To detect position of a metal we can use the eddy currents induced by a current carrying inductor. It is described in this link.

    http://www.marktec.co.jp/e/product/ndt/ect/principle.html [Broken]

    Would this still work if the target is a magnet enclosed in a metal casing. Basically I need to detect the position of a magnet that is enclosed in a metal casing.

    Thanks in advance
    Last edited by a moderator: May 7, 2017
  2. jcsd
  3. Dec 11, 2014 #2


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    Hi sensor

    welcome to PF :)

    The metal case is likely to shield the magnetic field. It would probably depend on the sensitivity of the sensor used to if it could detect
    any magnetic field that may or may not be outside the metal casing

    Others may have more ideas :)

  4. Dec 12, 2014 #3
    The system will detect metal casing.
    Modern metal detectors (like those on airports) usually use method of resonance coils.
    Last edited by a moderator: May 7, 2017
  5. Dec 12, 2014 #4
    If you place the magnet in a non-ferrous casing, such as copper, aluminum, titanium etc.... Then, you can sense the field created by the magnet by using reed switches, Hall sensors, or GMR sensors.
    This is a simple enough trick for measuring fluid levels in a container.
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