Fast Responding High Temperature Sensors For Combustion Control

It is clear that catalytic Metal-Oxide-Silicon Carbide, MOSiC, structures can be used as hydrocarbon sensors in the exhaust of car engines. They give a signal which is a complement to that from the /spl lambda/-sonds, i.e. a large signal is obtained in an excess of hydrocarbons. Furthermore it is demonstrated that the response of the MOSiC structures with a layer of TaSi/sub x/ deposited between the platinum gate and silicon dioxide are very fast. They appear to respond on rapid variations in the composition of the exhaust around /spl lambda/=1. It is concluded that the time constants of the devices must be substantially smaller than 100 ms.