Device and method for determining the thermal conductivity of a gas, tank arrangement and vehicle

A device for determining a leakage of hydrogen from a hydrogen tank, the device configured to be arranged outside a tank space of the hydrogen tank, comprising:

• an electrical conductor arrangement which is configured to be brought into contact with a fluid mixture, the conductor arrangement including a voltage divider having first and second elements, the first element being a first conductor which, in a current-carrying state, has a resistance value which is different from that of the second element, the second element being a second conductor, wherein a conductor path corresponding to the first conductor is arranged in a meandering manner between two middle legs of a conductor path corresponding to the second conductor,
• a measuring bridge comprising two voltage dividers connected in parallel, one of the voltage dividers being formed by the electrical conductor arrangement,
• a control unit, for applying an AC voltage to the measuring bridge,
• a voltage detection unit for detecting a bridge voltage, and
• an evaluation unit configured to:
• determine a hydrogen concentration in the fluid mixture based on a thermal conductivity of the fluid mixture, the thermal conductivity being determined by evaluating the bridge voltage using the 3-Omega method,
• determine the leakage of hydrogen from the hydrogen tank based on the determined hydrogen concentration in the fluid mixture, and
• output a signal upon determining the leakage.