Watlow and EmiSense Technologies, LLC are commercializing an improved electronic particulate matter (PM) sensor that has real-time measurement capability and improved sensitivity. To demonstrate the capability of this improved sensor of on board diagnostics (OBD) for failure detection of diesel particle filters (DPF), independent measurements were performed by university of California Riverside (UCR) and by Southwest Research Institute (SwRI) to characterize the engine PM emissions and to compare with the PM sensor response. In situ PM measurements from PM sensors correlate well with real-time gravimetric measurements. In addition, particle size and particle number data are presented and discussed.Due to an improved design update, the sensitivity of the sensor could have been significantly increased. PM concentrations below 1mg/m? can be reliable detected, which equals a threshold of ~2.5mg/km in the New European Driving Cycle (NEDC) for passenger cars, what is more than 3 times lower than the proposed threshold from the European Commission for OBD Stage 2 (9mg/km). The threshold of resistive soot sensors is currently limited to 13.7mg/km. A large measurement range enables this technology both for post-DPF and pre-DPF application. The sensor can be supplied with a CAN J1939 interface or a 0-5V analogue output.

Presenter
Magdi Khair, Magdiesel Technologies