The analysis of the PEMS measurements of the exhaust emissions from city buses using different research procedures

The paper discusses the possibilities of measurement of the exhaust emissions generated by city buses operating in public transit. The currently used methods of exhaust emission measurement under laboratory conditions on engine test beds do not entirely reflect the varied driving conditions under which the vehicles are operated. The paper presents the results of the in-use exhaust emission measurements performed on city buses using a Portable Emissions Measurement System (PEMS). The paper focuses on the road tests methodology as well as the interpretation of the obtained results.