Abstract
During the last few years the market share of vehicles with diesel engines has steadily increased. The reasons for this are the excellent features of this engine, especially its outstanding torque qualities and high efficiency. The development of the diesel engine is increasingly being affected by the stricter emission regulations for limited pollutants. The particulate and NOx-emissions in particular are to be reduced drastically within the next few years. A survey of state-of-the-art exhaust aftertreatment systems reveals high demand for further development and optimization. The main problem is reliable evaluation of these systems' functionality under all operation conditions, their secondary emissions, long term stability and maintenance intervals. The EU Commission is urging development of modern emission control technology and of the appropriate sensor technology to enable complete OBD monitoring of such exhaust aftertreatment systems. Many ambitious national and EU projects are being launched to create new exhaust pollutant sensors for the automotive industry that could help establish a multibillion euro market in emission control systems by 2010. The sensors will also help Europe to meet its CO2 obligations under the Kyoto Protocol. The major innovation in these projects is to create particulate sensors for the next generation of diesel exhaust emission control systems. Such a soot sensor, named Spark Discharge Soot Sensor (SDSS), has been developed by Hamburg University of Applied Sciences since 1998, (1). In principle the SDSS is designed as a combination of conventional spark and glow plugs. In this paper the construction, development and implementation of the SDSS is presented and commented upon. The SDSS was tested on many diesel engines and the measurement results of steady and unsteady tests are presented and analyzed in detail.
Keywords: Soot Sensor, On-Board-Diagnosis (OBD), On-Board-Measurement (OBM), Diesel-Particulate-Filter (DPF)