Abstract: The disclosure relates to a method for monitoring the quality of a fuel containing alcohol in a storage tank (1) including a sump area (8), wherein the density of the fluid present in the sump area (8) of the storage tank (1) is measured and compared to prescribed values characterizing the density of a mixed phase comprising water and alcohol as a function of the composition thereof.

Abstract: In a method for determining the gas volume flow in gas recirculation at a filling station, by means of a thermal throughflow sensor which is installed in the gas recirculation system of a gasoline pump, measurement values are detected, which represent the mass flow of the gas recirculated during refuelling operations from the respective tank of the motor vehicle to be refuelled into a storage tank of the filling station. Furthermore, information on the composition of the recirculated gas is detected, for example by means of a vapor-pressure curve or a thermal-conductivity measurement cell. The mass flow is determined from the measurement values obtained by the thermal throughflow sensor and the information on the composition of the recirculated gas, calibration data being used. This mass flow is converted into a gas volume flow characteristic of the region of the gasoline pump valves of the gasoline pump.

Abstract: A device for determining the density of a fluid comprises a buoyant body, a spring which engages on the buoyant body and whose elastic deformation is a measure of the buoyancy force of the buoyant body, and a magnet which is designed to sense the elastic deformation of the spring by means of a magnetostrictive position-measuring system. The spring is compressively loaded and, if the buoyancy force of the buoyant body is greater than its weight, said spring acts on the buoyant body underneath its centre of buoyancy. The device is preferably used to determine the density of fuel, a magnetostrictive filling level measuring system which is present in a storage tank for fuel being used.

Abstract: In a method for determining the gas volume flow in gas recirculation at a filling station, by means of a thermal throughflow sensor which is installed in the gas recirculation system of a petrol pump, measurement values are detected, which represent the mass flow of the gas recirculated during refuelling operations from the respective tank of the motor vehicle to be refuelled into a storage tank of the filling station. Furthermore, information on the composition of the recirculated gas is detected, for example by means of a vapour-pressure curve or a thermal-conductivity measurement cell. The mass flow is determined from the measurement values obtained by the thermal throughflow sensor and the information on the composition of the recirculated gas, calibration data being used. This mass flow is converted into a gas volume flow characteristic of the region of the petrol pump valves of the petrol pump. The method is suitable for monitoring the gas recirculation system of the petrol pump with high accuracy.

Abstract: A method of determining the gas return rate at filling stations is carried out at filling pumps with two filling points, a first filling point and a second filling point. Each filling point is assigned at least one fuel flow meter of its own and both filling points are assigned a common gas flow meter, which is arranged downstream of a meeting point of the gas streams of the two filling points. The measured values obtained from the two fuel flow meters and from the gas flow meter are recorded at short predetermined time intervals in assignment to one another. In the case of at least partially simultaneous refuelling operations at the two filling points, the information determined from the measured values of the fuel flow meters concerning the progression over time of the two refuelling operations is used for breaking down the measured sum of the gas flow of the two filling points into a gas flow assigned to the first filling point and a gas flow assigned to the second filling point.

Abstract: In an example method for detecting the fuel quantity during the refueling of a motor vehicle, the volume of the fuel conducted to the motor vehicle during the refueling operation and the temperature of the fuel are measured. The measured volume is corrected to predetermined temperature conditions by means of the measured temperature, specifically in a monitoring unit for a gas recirculation device. Preferably, a retrofitting kit for a device for carrying out the method contains a temperature sensor and an accessory for the monitoring unit for the gas recirculation system.

Abstract: 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.

Abstract: A gas recirculation system at a filling station is controlled during a refuelling process by generating a corrective control signal used for the next refuelling process, to actuate the gas recirculation system and control the gas volume flow, based on the fuel volume flow signal and the gas volume flow signal as well as optionally further signals.

Abstract: In a method for detecting the fuel quantity during the refuelling of a motor vehicle, the volume of the fuel conducted to the motor vehicle during the refuelling operation and the temperature of the fuel are measured. The measured volume is corrected to predetermined temperature conditions by means of the measured temperature, specifically in a monitoring unit (22) for a gas recirculation system. Preferably, a retrofitting kit for a device for carrying out the method contains a temperature sensor (28) and an accessory for the monitoring unit (22) for the gas recirculation system.

Abstract: 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.

Abstract: A gas recirculation system at a filling station is controlled during a refuelling process by generating a corrective control signal used for the next refuelling process to actuate the gas recirculation system and control the gas volume flow, based on the fuel volume flow signal and the gas volume flow signal as well as optionally further signals.

Abstract: In a method of measuring the throughflow of a gas mixture, the gas mixture flows past a flow sensor which includes a heating device and a first temperature probe reacting to the temperature of the heating device. A temperature, which is characteristic of the temperature of a liquid above which the gas mixture stands as vapor, is measured with a second temperature probe. A first measurement signal characterizing the composition of the gas mixture and thus its heat dissipation capacity is produced using the known vapor-pressure curve of the liquid and the temperature of the liquid. A second measurement signal characterizing the throughflow of the gas mixture is produced using the heating power supplied to the heating device, the temperature of the first temperature probe and the first measurement signal. The method can be used when monitoring the gas return to a filling system and when controlling the gas pump used therein.

Abstract: A thermal flow-rate sensor has a flow sensor (3) and a thermal-conductivity measuring cell (4). The flow sensor (3) comprises a first heating device and a first temperature detector, which reacts to the temperature of the first heating device, and can be exposed to a flowing fluid whose flow rate is to be determined. The thermal-conductivity measuring cell (4) comprises a measuring-cell casing (42), a second heating device and a second temperature detector which reacts to the temperature of the second heating device. The measuring-cell casing (42) has at least one opening (46) arranged for entry of the fluid into the measuring-cell casing (42).