Abstract: Exhaust gas analyzers are disclosed for analyzing the exhaust gases from a combustion process including a sensor unit mounted for direct contact with the exhaust gases in which the sensor unit includes a number of sensors such as lambda sensors, NOx sensors, oxygen sensors, and residual heat sensors, mounted on a common substrate for detecting specific gases and temperatures in the exhaust gases and generating signals based thereon, the substrate being an oxygen-ion-conductive ceramic material and the sensors elements including conductive patterns applied to the common substrate, and a common analyzer connected to the sensor units for analyzing the signals generated by the sensor elements.

Abstract: The invention relates to an arrangement for determining the oxygen buffer capacity in a catalytic converter (1) of an exhaust system. The arrangement includes an oxygen sensor (3, 32, 33) located downstream of at least one converter matrix (30, 31), where the sensor (3, 32, 33) supplies an input signal to a fuel injection control unit (4). The arrangement includes an analyzer circuit (13) for determining time information (TP) about the fluctuation of said input signal (25, 26), and calculating means for calculating the oxygen buffer capacity based on said time information (TP) when the downstream sensor is used to provide a primary control input signal (26). The invention also relates to a method of determining the buffer capacity.

Abstract: The present invention relates to a sensor for detection of oxides of nitrogen forming part of a gas, including a substrate consisting of a solid electrolyte on which a conductive pattern is arranged which includes at least two parts forming an anode and a cathode, a current being produced in the sensor in the presence of oxides of nitrogen and the anode and the cathode being connected to an external voltage source which is adapted to drive the current and to means for measuring the current, which constitutes a measure of the concentration of oxides of nitrogen in the gas. The sensor is adapted to generate the current by means of a transport of oxygen ions in the sensor which essentially originates from oxides of nitrogen being part of the gas, independently from the content of oxygen in the gas.