Leak testing of a container, especially a fuel tank and or the fuel degassing system of a motor vehicle, with means for supply of a test pressure, a reference orifice and an additional orifice to ensure correct operation

摘要

Device comprises a pressure source (30) that can be connected, via a changeover valve (32), to either the container or a reference orifice plate (42). The values of the reference pressure measured through the orifice plate and that applied to the fuel degassing system are compared to indicate the presence or not of a leak. In order to detect an inaccurate transport volume of the pressure medium through the reference orifice an additional orifice (44) with a different cross section is provided. Independent claims are made for: (1) a diagnosis unit; (2) a method for leak testing of a motor vehicle fuel tank and degassing system.