US Patent 7860671 High precision liquid level gauge system

High resolution liquid level gauge includes a float member with a buoyant, free end, and an opposing end rotatably attached to an interior surface of a reservoir such that the float member is free to rotate about an axis of rotation. A single magnet defining a single magnetic field is attached to the pivoting end such that the magnetic field is centered on the axis of rotation and rotates with the float member. A magnetic rotary encoder chip configured to detect angular position of the magnetic field is positioned to be aligned with the axis of rotation on the exterior of the reservoir at a distance from the magnet to detect the magnetic field. The encoder is configured to provide a signal representative of the angle of the magnetic field. A computer processor determines the liquid level within the reservoir based upon the signal.