Abstract: Disclosed herein is a fuel sensor suited for sensing the level of fuel in a motor vehicle fuel tank. The fuel tank includes an interior mounting to which the fuel sensor is affixed. The fuel sensor has a cantilever member extending in a substantially horizontal direction from the mounting to a free end. The cantilever member is substantially rigid but can be deflected in the vertical direction. A probe is affixed at the free end of the cantilever member to extend in a substantially vertical orientation approximately the full height of the fuel tank. A stabilizer member is affixed at one end to the mounting and at an opposing end to the probe. The stabilizer member has a pivot segment between the ends permitting the probe to move vertically but not horizontally. According to Archimedes's principle, the probe encounters a buoyant force equal to the weight of displaced fuel which induces strain in the cantilever member.

Abstract: An apparatus and method of for measuring fluid levels in a fluid tank (30) utilizing a no moving parts fluid level sensor (20). The apparatus comprises a hollow sensing tube (24) sealed to a pressure sensor (22). The pressure sensor (22) measures air column pressure as a function of hydrostatic pressure within the fluid tanks (30). By modifying the design of the hollow sensing tube (24) to incorporate at least 30% of the volume at its bottom end, the accuracy of the fluid level measurements may be increased by decreasing the meniscus level (34) deviation in the hollow sensing tube (24). Further, by adding a flexible diaphragm (62) to the bottom end that does not allow fluid to enter the hollow sensing tube (24), the accuracy of the fluid level measurements may be further increased by eliminating the meniscus level (34) altogether.

Abstract: A method of leak testing a walled tank (16) that has multiple joints containing closures or closure devices (18, 20, 22, 24) closing openings in the wall. Rims (38) of multiple cups (26, 28, 30, 32) are disposed against the tank wall to place the cup interiors in substantial sealed covering relation to underlying zones of the tank wall containing joints to be checked. A tank seal (52) is disposed fluid-tight against a fill spud (18) in the tank wall, and a test gas, helium, is introduced into the interior of the tank. Gas from within the interior of each cup is sampled via a respective sampling conduit (48), and a purge gas is introduced into the interior of each cup via a respective purge conduit (46) while the gas from the interior of each cup is being sampled via the respective sampling conduit.