Patent attributes
A ventilation-mast monitoring system for filling stations contains a thermal through-flow measuring device (30) and a hydrocarbon-measuring device (30). The thermal through-flow-measuring device (30) has a heating device and a temperature sensor which is located in the flow path and reacts to the temperature of the heating device, and is configured to sense the gas volume flow escaping from a reservoir tank (1) via a ventilation mast (4) of the reservoir tank (1) of a filling station or entering the reservoir tank (1). The hydrocarbon-measuring device (30) is configured to sense the direction of the gas volume flow escaping from or entering the reservoir tank (1) via the ventilation mast (4). A control device which is configured to receive and to process measuring signals emitted by measuring devices of the system is preferably provided as a further system component.