Determination of the Soot Mass by Conductometric Soot Sensors

Soot sensors are required for on-board diagnostics (OBD) of automotive diesel particulate filters (DPF) to detect filter failures. If installed upstream of a DPF, the “engine-out” soot emissions can be determined by conductometric soot sensors. For that purpose, conductometric soot sensors were characterized in a diesel engine under varying operation conditions. Sensor data and soot analytics (SMPS) agree well. However, the orientation of the sensor electrodes with respect to the exhaust flow direction significantly affects the sensor signal.