Patent ID: 6583631
Filing Date: 2003-06-24
Classification: G01R

Abstract:
A cost-effective, sensitive liquid dielectric constant sensor assembly comprising:a housing; a securing mechanism for holding the housing onto a container for liquid; a flat circuit board having a printed capacitor thereon, the capacitor being in the form of a pair of sets of closely spaced conductive lines or passageways printed on the circuit board, said lines being less than 0.050 inch apart; said circuit board being mounted within said housing to extend outwardly from the securing mechanism with said conductive lines being exposed to the liquid when the housing is mounted on the container; said flat circuit board having two ends, with a signal processing circuit including printed circuitry directly mounted onto said flat printed circuit board, mounted on one end thereof, said printed capacitor being formed on the other end thereof and wherein the printed circuitry for said signal processing circuitry is substantially coplanar with said printed capacitor; seal arrangements extending around said circuit board between said printed capacitor and said signal processing circuit, and between said circuit board and said housing, to block liquid from said signal processing circuit; and at least one opening in said housing to permit fluid flow to said printed capacitor.