Comparison of exhaust emission results obtained from Portable Emissions Measurement System (PEMS) and a laboratory system

Exhaust emissions testing of vehicles under real driving conditions (real driving emissions, RDE) using portable exhaust emissions measurements systems (PEMS) was introduced a few years ago by the European Commission as a mandatory test during type approval and later also for in-service conformity. This paper compares results from mobile systems for measuring exhaust gas emissions (PEMS) with a stationary laboratory (BOSMAL’s Exhaust Emissions Testing Laboratory). The tests were carried out using a passenger car equipped with a spark ignition engine, which was tested on chassis dynamometer over the WLTC cycle. The results showed that the differences between PEMS analysers and stationary analysers range from a few percent to a dozen or so percent, depending on the component and the measurement method.