Patent ID: 6840089

Claim:
A fuel tank tester utilizing an external source of pressure for testing purposes comprising means for connecting the external source of pressure to said fuel tank tester, means for connecting said fuel tank tester to the fuel tank being tested, means for determining the pressure within the fuel tank being tested, a reference orifice contained within said fuel tank tester, means for directing gas from the fuel tank to said reference orifice, means for determining the time required for the pressure within the fuel tank to decay, between predetermined pressure levels, through any leaks which might exist in the fuel tank and the time required for the pressure within the fuel tank to decay, between predetermined pressure levels, through the combination of any leaks which might exist in the fuel tank and said reference orifice when said means for directing gas from the fuel tank to said reference orifice is actuated, and means for comparing said times determined by said time determining means with predetermined ratiometric time relationships for said pressure decays to occur in order to determine whether the fuel tank has an acceptable leakage rate.