Patent ID: 7017409
Filing Date: 2006-03-28
Classification: G01F

Abstract:
1. An apparatus for sensing the level of a substance contained in a tank having a bottom portion and a side wall portion, comprising: a first, thin planar electrode associated with said side wall portion; a second, thin planar electrode associated with said side wall portion; said second electrode arranged on said side wall portion substantially above said first electrode with respect to said bottom portion; said first electrode coupled to a first resistor and to a first input of a detection circuit; said second electrode coupled to a second resistor and to a second input of a detection circuit; a strobe line coupled to said first resistor and said second resistor; wherein said detection circuit produces a low-level output when said fluid substantially covers neither said first nor said second electrode; wherein said detection circuit produces a low-level output when said fluid substantially covers both said first and said second electrode; wherein said detection circuit produces a high-level output when said fluid substantially covers one, but not both, of said first and said second electrodes.