Patent ID: 8366670

Claim:
A contrast media injector system comprising: a faceplate mounting region at which magnetic sources of a faceplate may be located; a Hall effect sensor associated with a location of said faceplate mounting region at which a magnetic source of a faceplate may be located; an analog circuit configured for measuring an analog signal representative of magnetic flux impinging upon said Hall effect sensor; a stored threshold analog signal value that is of an analog magnitude that is between first and second signal levels, said first signal level being from a first analog signal output by said Hall effect sensor when a faceplate is attached to said faceplate mounting region, and said second signal level being from a second analog signal output by said Hall effect sensor when the same faceplate is detached from said faceplate mounting region; and a control circuit coupled to said analog circuit for determining whether a magnetic source of a faceplate has one of at least three states based upon said analog signal and said stored threshold analog signal value.