FIELD: engines and pumps.
SUBSTANCE: invention relates to the purification of internal combustion engine exhaust gases. Invention relates to a method and apparatus for operating sensor (7) provided in an exhaust system of internal combustion engine (1) to determine the emissions contained in the exhaust gas stream, in particular nitrogen oxides, ammonia, oxygen and/or soot. Between the measured phases, sensor (7) is at least substantially released from the exhaust gas stream, wherein the duration and/or frequency of measurement phases can be set depending on the operating parameters of internal combustion engine (1) and/or the exhaust gas control system. Measurement space (6), surrounding sensor (7), immediately after the measurement phase is exposed to pressurized purge gas, so that the exhaust gas in the measurement space is displaced from the measurement space into the exhaust gas stream.
EFFECT: service life of the sensor is extended by means of using the invention.
17 cl, 6 dwg
