Patent ID: 7228743

Claim:
A variable capacitive sensor, which comprises: an outer shell defining a first electrode of the capacitive sensor, the outer shell having an axial bore formed therethrough, and having at least a first open axial end in fluid communication with the axial bore; at least a first piston reciprocatingly axially movable within the bore of the outer shell, the at least first piston defining a second electrode of the capacitive sensor; at least a first piston shaft, the at least first piston shaft being connected to the at least first piston; and at least a first end cap bearing, the at least first end cap bearing being mounted on the outer shell at the at least first open axial end thereof, the at least first end cap bearing having a shaft opening formed through the thickness thereof, the at least first piston shaft being received by and reciprocatingly slidably moveable in the shaft opening.