Improvement in PEMS performance for RDE testing at high and varying altitudes

RDE (Real Driving Emissions) by definition is performed under a wide range of conditions. Altitude, as well as temperature, is one of the boundary conditions that depends on the area where the test is performed, which will vary from country to country. These boundary conditions not only affect the exhaust emissions from the vehicle, they also affect the accuracy of the PEMS (Portable Emission Measurement System).

The effect of barometric pressure changes on a PEMS was evaluated by altitude simulation chamber and means of an RDE test on Mt. Fuji. This paper describes the challenges for PEMS measurement with barometric pressure variations and the advanced system that has been developed to meet them.