Patent ID: 6297733
Filing Date: 2001-10-02
Classification: G01F,G01N

Abstract:
A reliable capacitive fluid deterioration and level sensing system comprising:a housing member comprising of an outer conductive shielding member, said shielding member having an inner surface defining a ground electrode, wherein the conductive shielding member precludes interference by adjacent metallic structures, said shielding member having at least one inlet port for a fluid, the housing member further having a threaded outer surface adapted to be threaded to a fluid container;a conductive inner member with an outer surface defining a measuring electrode, said inner member being secured within said housing member and spaced from the shielding member by an insulating material to allow the fluid from the inlet port to occupy said space, such that said ground electrode and said measuring electrode define a fluid deterioration and level sensor variable capacitor;said outer conductive shielding member at least partially extending over the outer end of said conductive inner member;said shielding member substantially enclosing said conductive inner member and extending over the greater portion of and more than half of the combined areas of said measuring electrode and the gap between electrodes, both as viewed from the sides and as viewed from the outer end of said conductive inner member;an electrical connector structure adapted to provide an electrical interface; andelectronics positioned within said housing member, said electronics being electrically connected to said fluid deterioration and level sensor capacitor, and said electrical connector structure, said electronics being adapted to generate a fluid deterioration output signal and a fluid level output signal employing said fluid deterioration and level sensor capacitor, and to provide said signals to the electrical connector structure.