Technical Paper
On Board Fast Measurement of Vehicle NOx Emissions
2018-04-03
2018-01-0646
An on-board version of a fast response chemiluminsescence analyzer with a 3-millisecond response time enables the recording of high temporal resolution transient NOx emissions during cold start and pull-away, gear changes, speed bumps and other real world transient conditions. Tests were initially performed on a 1.6 litre turbo GDI vehicle before comparison with a diesel vehicle. The data has been correlated with on-board engine data available from the vehicle’s electronic control unit to study the underlying causes of these short-duration events. Exhaust gas was generally sampled from downstream of the after treatment system but before the silencer (muffler) to preserve all high frequency detail and to allow accurate integration of pollutant concentration and engine exhaust mass flow.
