Sensor array comprising metal oxide semiconductor gas sensors which are operated as resistors, whereby each sensor consists of a contact electrode (contact pad) applied to a substrate and of a sensor-active layer deposited on said substrate, whereby at least some of the sensors have a different contact spacing L with the contact pads of other sensors and/or a different dimensioning of the surface of the sensor-active layer and/or a different contact boundary surface A between the contact and the sensor-active layer.