A Linear Position Transducer Using a Magnet and Hall Effect Devices

Magnets and magnetic field sensing devices are often attractive in instrumentation because they are noncontacting, small, and independent of the media´s dielectric constant. The nonlinearity of the magnetic field with distance is a problem, however. A circuit to remove this nonlinearity and also to reduce the effective temperature coefficient is described. The circuit is used in a clinical dental research laboratory to measure movements of the jaw.