SENSOR FOR DETERMINING THE OXYGEN CONCENTRATION IN INTERNAL COMBUSTION ENGINES

摘要

The invention relates to a sensor for determining the oxygen concentration in the exhaust gas of internal combustion engines. Said sensor comprises a sensor element (12), housed in a sensor housing (10) and projecting with one gas-sensitive section (121) from said sensor housing (10), and a hood-type protective tube (13), fastened on the sensor housing (10) and covering the gas-sensitive section (121). Said protective tube surrounds a measuring space (15) which is contacted with the exhaust gas in a gas-exchanging manner via gas passages (14) in the protective tube (13). In order to prevent the sensor element (12) from being contaminated in an aggressive thermal and chemical environment, the measuring space (15) is provided with a porous, reactive, ceramic absorption material (16) surrounding the gas-sensitive section (121) of the sensor element (12) for physically and/or chemically binding any components contained in the exhaust gas that might be harmful to the sensor element (12).