permanentmagnetic linear contactless displacement (sensor) (PLCD)

Permanent Magnetic Linear Contactless Displacement (PLCD) is a technique used in field strength controlled sensors, similar to Anisotropic Magneto-Resistive( AMR) and Giant Magneto-Resistive( GMR).

Like the other techniques, the PLCD technique also operates in a saturation-induced manner. A PLCD element consists of a soft magnetic material surrounded along its length by a primary coil. The PLCD element is driven by a permanent magnet, which leads the soft magnetic material into saturation at the position where the permanent magnet approaches the material. The position at which saturation occurs is sensed by coils on the transverse sides.

Since PLCD elements are operated in the saturation region, they are relatively insensitive to field strength fluctuations, temperature effects on the magnetic material and to the change in distance of the permanent magnet.