Patent ID: 7908099

Claim:
A method of detecting a leak in a fuel system comprising a fuel tank and an orifice with a controlled section between the tank and the atmosphere, according to which: a) the controlled section is set to a value A 1 at a time T 1 and a pressure differential Δp 1 between the inside of said fuel tank and the atmosphere is measured at least after an interval of time ΔT from T 1 , for a constant fuel flow out of said fuel tank; b) the controlled section is set to a value A 2 at a time T 2 and a pressure differential Δp 2 between the inside of said fuel tank and the atmosphere is measured at least after the same interval of time ΔT from T 2 , for the same constant fuel flow; c) a ratio of said pressure differentials Δp 1 and Δp 2 is computed and is compared to a reference pressure differential ratio Δp L obtained with the same fuel system but comprising a calibrated leak; and d) a leak bigger than said calibrated leak is detected if said ratio computed at stage c) is smaller than said reference ratio Δp L .