Patent ID: 7398682

Claim:
A low fluid level detector, comprising: a substantially annular float having a substantially hollow interior disposed in a reservoir containing a level of fluid; a ring magnet disposed in the interior of the float, the ring magnet substantially co-axial with the float; a primary Hall effect sensor disposed at a first distance from a face of the ring magnet, and a secondary Hall effect sensor disposed at a second distance from a face of the ring magnet, said second distance being greater than said first distance, both said primary Hall effect sensor and said secondary Hall effect sensor located outside of the reservoir, each of the primary and secondary Hall effect sensors for detecting the strength of the magnetic field caused by the ring magnet according to the first and second distances, respectively, such that the first distance between the face of the ring magnet and the primary Hall effect sensor is determined, and the second distance between the face of the ring magnet and the secondary Hall effect sensor is determined, and such that the level of fluid in the reservoir is determined based upon the first distance and the second distance.