A gas-measuring system contains at least one gas sensor (1) and at least one gas generator (4). The gas sensor (1) has at least one measuring surface (3), at which a target gas concentration can be measured. The gas generator (4) has at least one discharge surface (5), from which a current-proportional quantity of test gas can be discharged. The measuring surface (3) and the discharge surface (5) are designed and the gas sensor (1) and the gas generator (4) can be arranged such that the measuring surface (3) and the discharge surface (5) are in direct contact with the ambient atmosphere and the distance between the two surfaces is shorter than the extension of the smaller of the two surfaces.