Detection means for measuring the displacement movement of an exhaust gas sensor flap

Detection means for measuring an angular position and / or an adjustment of a in an exhaust device of an internal combustion engine on a shaft (28) pivotably mounted flap (16) having means (32, 26; 36) for transmitting the angular position and / or adjusting movement at one of the exhaust device spaced location at which a trained to detect the transmitted angular position and / or adjusting the sensor unit (30; 31) is arranged, characterized in that the transmission means (26, 32) is at least partially formed as a train-pressure means and the transmission means (26, 32) at least (at the shaft in the region of the connection 28) comprises a material having a low thermal expansion coefficient.