Sensor for the detection of actual concentrations of several gas compounds in a gas

摘要

Measuring probe has a first region for determining the instantaneous concentration of oxygen, a second region for determining the instantaneous concentration of ammonia, and a third region for determining the instantaneous concentration of nitrogen oxide. Independent claims are also included for: (A) a catalyst system for reducing nitrogen oxides in combustion gases comprising the measuring probe arranged at the catalyst exit and/or in the catalyst at the site of ammonia injection; and (B) a process for minimizing the ammonia and nitrogen oxide output from the catalyst system comprising using the measured results of the probe to regulate ammonia injection.