Sensor for determining nitrogen oxides in vehicle exhaust gas

摘要

Electrodes are used which are inactive to reduction of NOx and active to a reduction of O2. The oxygen concentration is finely adjusted using an oxygen pump cell. The gas to be examined is passed into a 1st chamber through a small orifice. Its oxygen content is determined and this oxygen content is adjusted to a predetermined value by an oxygen pump. The gas is passed to a 2nd chamber where its nitrogen oxide concentration is determined electrochemically using an apparatus in which an electrode pair is formed on a solid electrolyte (B).