INDUCTIVE SENSOR FOR MONITORING FLUID LEVEL AND DISPLACEMEMT

摘要

A sensor system for measuring the level of a fluid includes a tube having a primary coil and a pair of secondary coils wound thereabout. The secondary coils have a periodically varying winding density distribution. The winding density distribution of one secondary coil is shifted relative to the winding density distribution of the other secondary coil. A float positioned adjacent the tube modifies an electromagnetic field produced by the primary coil. In response to the modified electromagnetic field, the first and secondary coils produce first and second signals having amplitudes that vary periodically in response to the movement of the float between the ends of the tube.