Development of a diesel smoke sensor using a spark plug

This research has continued the development of a new sensor for use in on-board monitoring for the control and diagnostics of smoke levels in exhaust emissions from a diesel engine. It uses a uniquely designed spark plug installed downstream from the diesel exhaust manifold. This sensor exploits the effect smoke particles have on the arc-to-glow transition of spark plug voltage and current signals, which are then converted into a representative smoke sensor voltage. The custom designed electronic circuitry captures the breakdown voltage triggered signal through the use of comparator circuits to differentiate between the respective voltage and current levels representative of the arc and glow phases. The current spark plug design has produced very favourable results in its ability to monitor the changing smoke levels. The next iteration of the sensor design should be fully adaptable to an existing vehicle control system and implemented for commercial use as an on-board smoke control monitor.