Abstract: An inductive sensor is comprised of a sealed housing; at least one current path disposed in the housing; means for applying current to the current path; variable low reluctance magnetic path about the current path; and means for sensing the output from the current path as a function of variations in the magnetic flux path. Alternative current path configurations include a differential transformer, comprised of a permanent magnet or one or more primary coils in conjunction with two secondary coils, or a voltage divider, comprised of two primary coils. The variable magnetic flux path includes ferromagnetic fluid disposed in the housing to a level at which all coils are at least partially submersed. Tilt or other displacement of the sensor results in a change in the amount of fluid contacting the coils and a resultant change in current output from the current path means. The change in sensed voltage is indicative of displacement and sustained output voltage is proportional to the degree of tilt of the sensor.

Abstract: A sensor for measuring angular displacement of a small body comprising a sealed housing containing a differential transformer having at least two primary coils, one primary and two secondary coils, or two primary and two secondary coils, said coils being partially submerged in a ferromagnetic fluid. Upon application of an AC current to at least the primary coils of the differential transformer, the voltage across the circuit defined by the two primary or the two secondary coils is indicative of the angle of tilt of the sensor and the body to which it is attached.