Patent ID: 7284422

Claim:
A measurement device for measuring the fluid level of a fluid, the measurement device comprising: a housing having a top end, a bottom end, a hollow interior, and a first opening located proximate the bottom end for allow the fluid to enter the hollow interior; a cap having a second opening attached to the top end; a shaft having a base and a top such that the shaft protrudes through the second opening of the cap and is capable of sliding up and down through the second opening and such that the base is disposed within the hollow interior; a first ring encompassing the shaft and capable of sliding along the shaft, the first ring disposed below the cap; a second ring encompassing the shaft and capable of sliding along the shaft, the second ring disposed above the cap; and wherein the first ring is positioned in abutting relationship with the cap and the second ring is positioned in abutting relationship with the cap and as the fluid enters the interior of the housing and rises within the interior, the shaft rises in lockstep with the rise in the fluid level such that the cap slides the first ring downwardly along the shaft toward the base and as the fluid level within the interior falls, the cap slides the second ring upwardly along the shaft toward the top.