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 , no x 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 .