Abstract: A system including a method and means for trimming capacitive-type remotely-located fuel probes that eliminates the previously-used variable trim capacitor and substitutes a rugged, inexpensive, standard-value signature resistor connected between the AC input and ground to provide "calibration offset" data needed by the fuel measurement electronics to make a determination of actual probe capacitance. The system may be applied to any such probe having a blocking capacitor in series with the probe capacitor, which blocking capacitor insures accurate measurement of the signature resistor when the leakage resistance is significant. When applied to DC or AC FHC probes, the C.sub.fhc capacitor is replaced with a non-critical DC-blocking capacitor, that is typically at least 100 times greater in capacitance value than the C.sub.

Abstract: A characterized inner electrode for a capacitive fuel-gauging probe comprises several discrete tubular sections of different diameters which are joined together end-to-end by metal coupling pieces. One or more of the tubular sections has two regions of different diameters that are continuous with one another, the smaller diameter region being formed by swaging down from the larger diameter region. The coupling piece has two shoulders to which the ends of the tubular sections are electron-beam welded. The coupling piece also has respective annular recesses into which a low viscosity adhesive is introduced via overlying apertures in the tubular sections after welding, so as to form an adhesive joint between the coupling piece and the tubular sections. The ends of the coupling piece are a close fit within the tubular sections and extend into them by a distance at least twice the diameter of the coupling piece.

Abstract: A capacitance fuel-gauging probe is supported at its upper end in a fuel tank by a stress-relieving mount. The mount includes a disc assembly formed of two identical steel discs each with a central aperture. The discs are joined together at their respective outer edges and around their respective central apertures by steel rings which separate the discs from one another, forming an annular recess. The ratio of the estimated disc stress to the disc material proof stress, and the ratio of the estimated probe stress to the probe material proof stress are substantially the same and as small as possible. A bolt extends through the aperture, the probe being clamped to the center of the disc assembly by a nut. The outer edge of the disc assembly is clamped securely with the wall of the fuel tank by a collar screwed into a sleeve within which the disc assembly is located. Any vibration of the probe during use causes flexing of the disc assembly so as to damp the vibration.

Abstract: A capacitive fluid-gauging probe has a tubular electrode that is secured at its upper end to the wall of a reservoir by an integral mount moulded from a frangible plastics material. The mount has a collar that is fitted to the probe and from which extend radially three pairs of struts. The struts are joined at their outer ends with respective pillars that extend parallel to the probe. The pillars are joined with a plate that is secured to the wall of the reservoir above the probe. Domed plugs are inserted in both ends of the electrode to protect the wall of the reservoir which may be of flexible material. Preferably the ends of the probe are spaced from the reservoir walls. In operation, excessive force on the probe causes the struts to break, thereby allowing the probe to be displaced within the reservoir.