Gas sensor, used for determining concentration of gas component, especially exhaust gas from internal combustion engine, comprises electrode having recess

摘要

Gas sensor used for determining the concentration of a gas component, especially an exhaust gas from an internal combustion engine, comprises at least one electrode (111) having a recess (150a) extending from the region near the vertical projection of the center of a diffusion barrier (130) on a layer plane of the electrode at least approximately in the direction of the longitudinal axis of a sensor element (110). Preferred Features: A heating device regulated by a combined resistance is provided in a layer plane of the sensor element. The combined resistance comprises the internal resistance of an electrochemical cell and at least one other resistance which can be subjected to deviations from a nominal value. The recess is designed so that any deviation of the other resistance from a nominal value is at least partly compensated for by an opposing change in the resistance of the electrochemical cell. The diffusion barrier is located in a measurement region (121) of the sensor element. The recess extends from the vertical projection of the center of the diffusion barrier on a layer plane of the electrode in the direction of a feed region (122) of the sensor element facing away from the measurement region.