Abstract: A portable emissions test apparatus for testing for vapor emitting leaks in a fuel holding system in a vehicle includes a pressurizing system and a pressure-monitoring system. The pressurizing system includes a first pressure regulator configured for connection to a source of pressurized gas for regulating a maximum first pressure in the apparatus downstream of the first pressure regulator, and a first surge protector connected to the first pressure regulator for controlling first surges from the first pressure regulator. The pressurizing system further includes an adjustable second pressure regulator operably connected to the first surge protector for adjustably regulating a second pressure of pressurized gas for operating the apparatus, the second pressure regulator including an adjustment knob positioned in a readily accessible position on the apparatus so that the pressure downstream of the second pressure regulator can be adjusted for changes in ambient atmospheric pressure.

Abstract: An evaporative emissions test apparatus is provided including a tester adapted to pressure test a vehicle fuel holding system for vapor emitting leaks. The test apparatus includes an adapter configured to sealingly engage the access port for filling the fuel tank, the adapter being further configured to sealingly receive the vehicle fuel cap so that the vehicle fuel holding system including the fuel cap can be tested as a unit. The tester includes a connector for connecting to the adapter, and further includes a second connector for connecting to a pressure source for pressurizing the fuel holding system and fuel vapor control system to a predetermined pressure. The tester also includes a sensor for sensing the pressure over time, a timer for indicating the passage of a predetermined amount of time, and a display generator and display for indicating if the pressure in the atmosphere is acceptable after passage of the predetermined amount of time.