Displacement sensor

A displacement sensor comprising;

• a sensor body having a substrate (16), a plurality of saturable inductors connected alternately in series mounted on one surface of said substrate radially with a predetermined angular period, each of said saturable inductors having a saturable magnetic core and a coil wound on the core, a process circuit (15) for processing output of said saturable inductors mounted on the other surface of said substrate, a lead wire coupled with said process circuit for supplying power to said process circuit and obtaining output of the process circuit, a shield case (31) surrounding said process circuit, and a housing (32) for securing above members having a ring (32a) on external wall of the housing, and
• a magnet assembly having a bottom ring (38a) with a plurality of upright wall chips (41) positioned perpendicularly at periphery of said bottom ring, a film (39) having a permanent magnet at center of said film attached to said bottom ring, each of said wall chips having a jaw at the extreme end so that said jaw engages detachably with said ring (32a) of the housing (32), and a plurality of bars (43) fixed to said bottom ring (38) so that it touches with said sensor body when it is engaged with the magnet assembly, and said magnet is positioned close to said saturable inductors.