Method and apparatus for sensing oxides of Nitrogen.

摘要

The present invention relates to a structure and a method for sensing oxides of nitrogen in a gas, for example, the exhaust gas of an internal combustion engine. The measurement gas along with oxygen provided by a solid state electrochemical oxygen pumping cell (10) is passed through an oxidation catalyst (17) to oxidise and remove any reducing species in the gas, e.g., carbon monoxide, hydrocarbons, and hydrogen. The oxides of nitrogen are then sensed by a gas sensor (19) which otherwise would respond to both oxides of nitrogen and reducing species in the gas.