Abstract: The present invention relates to a fuel cell system (100) comprising at least one fuel cell stack (1) having at least one cathode section (K) and at least one anode section (A), an air supply section (2) for supplying air (2) to the anode section (A) of the fuel cell stack (1), an exhaust air section (4) for discharging exhaust air (5) from the anode section (A) of the fuel cell stack (1), as well as a supply section (7) for supplying at least one main medium (6) to the cathode section (K) of the fuel cell stack (1), an exhaust gas discharge section (9) for discharging exhaust gas (8) from the cathode section (K) of the fuel cell stack (1), as well as a pump (12) for delivering the at least one main medium (6), the exhaust gas discharge section (9) being fluidically connected via a recirculation section (14) to the supply section (7) downstream of the pump (12) in order to recirculate exhaust gas (8), the recirculation section (14) being connected via a jet pump (16) to the supply section (7) in order to intr

Abstract: The present invention relates to a fuel cell system (100) comprising at least one fuel cell stack (1) having at least one cathode section (K) and at least one anode section (A), an air supply section (2) for supplying air (2) to the anode section (A) of the fuel cell stack (1), an exhaust air section (4) for discharging exhaust air (5) from the anode section (A) of the fuel cell stack (1), as well as a supply section (7) for supplying at least one main medium (6) to the cathode section (K) of the fuel cell stack (1), an exhaust gas discharge section (9) for discharging exhaust gas (8) from the cathode section (K) of the fuel cell stack (1), as well as a pump (12) for delivering the at least one main medium (6), the exhaust gas discharge section (9) being fluidically connected via a recirculation section (14) to the supply section (7) downstream of the pump (12) in order to recirculate exhaust gas (8), the recirculation section (14) being connected via a jet pump (16) to the supply section (7) in order to intr

Abstract: A piezoelectric sensor device, especially for use with a microbalance, with a sensor housing and a holder for holding a piezoelectric sensor element. In order to permit quick exchange of crystals and to minimize the size of the assembly, the holder is configured as a clamping element which has at least one elastic first arm for clamped holding of the contact region of the essentially strip-shaped piezoelectric resonator element, whose measuring region is subjected to a fluid stream to be measured.

Abstract: The invention relates to a piezoelectric sensor device, especially for use with a microbalance, with a sensor housing and a holder for holding a piezoelectric sensor element. In order to permit quick exchange of crystals and to minimize the size of the assembly the holder is configured as a clamping element, which has at least one elastic first arm for clamped holding of the contact region of said essentially strip-shaped piezoelectric resonator element, whose measuring region is subjected to a fluid stream to be measured.

Abstract: The invention relates to a device for supplying at least one process gas, with independently set temperature and mass flow, in an input line of a test bed for fuel cells or fuel cell components, such as reformer, catalytic converter, etc. At least two dynamically controlled gas injectors are provided for each process gas, which are connected to feeder lines for two partial streams each at defined but different temperature levels, and which open into the input line for the process gas.