Evaluation of a 10 nm Particle Number Portable Emissions Measurement System (PEMS)

On-board portable emissions measurement systems (PEMS) are part of the type approval, in-service conformity, and market surveillance aspects of the European exhaust emissions regulation. Currently, only solid particles >23 nm are counted, but Europe will introduce a lower limit of 10 nm. In this study, we evaluated a 10-nm prototype portable system comparing it with laboratory systems measuring diesel, gasoline, and CNG (compressed natural gas) vehicles with emission levels ranging from approximately 2x10^10 to 2x10^12 #/km. The results showed that the on-board system diered from the laboratory 10-nm system on average for the tested driving cycles by less than approximately 10% at levels below 6x10^11 #/km and by approximately 20% for high-emitting vehicles. The observed dierences were similar to those observed in the evaluation of portable >23 nm particle counting systems, despite the relatively small size of the emitted particles (with geometric mean diameters <42 nm) and the additional challenges associated with sub-23 nm measurements. The latter included the presence of semivolatile sub-23 nm particles, the elevated concentration levels during cold start, and also the formation of sub-23 nm artefacts from the elastomers that are used to connect the tailpipe to the measurement devices. The main conclusion of the study is that >10 nm on-board systems can be ready for introduction in future regulations.

GIECHASKIEL Barouch;  MAMAKOS Athanasios;  WOODBURN Joseph;  SZCZOTKA Andrzej;  BIELACZYC Piotr; 

2020-01-07

MDPI

JRC118722

1424-8220 (online),   

https://publications.jrc.ec.europa.eu/repository/handle/JRC118722,   

10.3390/s19245531 (online),