US Patent 7222528 Fluid level sensor

A fluid sensor arrangement (20) includes a sleeve (32) that is adapted to be placed within a container (24). A plurality of conductors (46, 48) and a channel member (50) within the sleeve cooperate to provide a measurement of conductivity of the fluid within the sleeve (32). The conductivity measurement provides an indication of a level of fluid within the container (24). A disclosed example includes a non-conductive channel member (50) having an opening or a channel (52) for directing selected portions of a conductivity field within the sleeve (32) between the conductors (46, 48) for making the conductivity determinations.