US Patent 7584644 Calibrator for fuel pump

The inventive device comprises scaled vessels mounted on a vehicle and making it possible, while filling a liquid medium in the vessels, to recycle the vapors thereof through a circuit of casings beginning form he reading sights of the vessels and extending to an air-vent pipe provided wit a removable valve, wherein the bottom of each vessel is embodied such that it is inclined and is followed by a valve, a transparent dripping reference unit and a second valve open into a common tube and ending by an ultimate valve.