Non-contact inductive pickup for determining the interface between two media

A non-contact inductive pickup for determining the interface between two media which have different specific density and different specific resistance, at least one of the media being electrically conductive and non-magnetic, said pickup comprising:

• two open U-shaped magnetic circuits, said open U-shaped magnetic circuits being disposed in separate planes parallel to each other, the legs of said open U-shaped magnetic circuits being pointed in the direction of the interface between the two media when said pickup is mounted for determining said interface, an excitation winding means embracing said open U-shaped magnetic circuits for providing a magnetic flux in said two magnetic circuits in the same direction upon application of an AC voltage to the input terminals thereof, and measuring windings embracing said U-shaped magnetic circuits and connected to each other for producing opposing emf's, which emf's vary during operation of the pickup to provide a determination of the interface between the two media.