Abstract: A method is provided for determining the amount of ammonia which is stored in a storage container by a chemical bond to a solid storage medium, in particular a salt of an earth alkaline metal or the like, and which can be released by supplying heat in order to be supplied to a catalytic exhaust gas purification device of an internal-combustion engine. The storage medium functions as a dielectric of an electric capacitor and the stored amount of ammonia is inferred from the capacity of this capacitor. One wall of the housing of the storage container functions as a first electrode of the capacitor, and, within the storage container, at least one additional electrode is arranged such that at least a partial amount of the storage medium forms the dielectric. The storage container may have an essentially cylindrical shape. Several cylindrical electrodes can be arranged in a coaxial manner.

Abstract: A method is provided for determining the amount of ammonia which is stored in a storage container by a chemical bond to a solid storage medium, in particular a salt of an earth alkaline metal or the like, and which can be released by supplying heat in order to be supplied to a catalytic exhaust gas purification device of an internal-combustion engine. The storage medium functions as a dielectric of an electric capacitor and the stored amount of ammonia is inferred from the capacity of this capacitor. In the case of a corresponding storage container, at least one wall of the housing of the storage container functions as a first electrode of the capacitor, and, within the storage container, at least one additional electrode of this capacitor is provided and arranged such that at least a partial amount of the storage medium forms the dielectric of this capacitor. The storage container may have an essentially cylindrical shape and, as required, several cylindrical electrodes can be arranged in a coaxial manner.

Abstract: The invention relates to an air filter system comprising at least one drum filter, the surface area of this filter being provided with a filter medium, and a suction device for cleaning the inside of the surface area, wherein a driving device displaces at least one suction element for the cleaning process in circular motions along the inside of the surface area as well as axially in the direction of the longitudinal axis of the drum filter. It is provided that the drum filter (4) is disposed with the longitudinal axis (6) extending vertically.

Abstract: A device and method for testing seal tightness of a fuel tank system of a motor vehicle, wherein excess pressure is built up in the fuel tank system by an electrically operated pump and electric current consumption of the pump is compared to reference values in order to determine whether the seal tightness of the fuel tank system is sufficient, and wherein the fuel tank system includes a filler neck with a locking fuel tank cap. A control line is connected in parallel to the power supply line of the pump, the control line being guided across an electric tank cap switch, which assumes a different switch state when the filler neck is closed properly than when it is not closed properly. In at least one of these lines, an electric resistor is installed, which allows a determination of the switch state of the tank cap switch.

Abstract: A device and method for testing seal tightness of a fuel tank system of a motor vehicle, wherein excess pressure is built up in the fuel tank system by an electrically operated pump and electric current consumption of the pump is compared to reference values in order to determine whether the seal tightness of the fuel tank system is sufficient, and wherein the fuel tank system includes a filler neck with a locking fuel tank cap. A control line is connected in parallel to the power supply line of the pump, the control line being guided across an electric tank cap switch, which assumes a different switch state when the filler neck is closed properly than when it is not closed properly. In at least one of these lines, an electric resistor is installed, which allows a determination of the switch state of the tank cap switch.

Abstract: A fan having a rotor with a plurality of fan blades, the fan having an intake and a pressure side. A blocking device between the intake and pressure sides of the fan. The blocking device comprising a strip-like brush element with a plurality of brush sections that extend radially upwardly toward the edge of the rotor. The brush sections are spaced apart from one another along the direction from the intake to the pressure side of the fan. A cross-flow fan has spaced apart brush sections which are spaced apart in the running direction of the fan. An axial flow fan has brush sections which are spaced apart from one another transversely with respect to the running direction. The brush sections in each of the fans may also be as in the other type of fan. The brush sections may define a v-shape extending from a common block or may be in spaced apart rows or may be individual tufts and the tufts may be staggered along the length of the brush.