Abstract: A device for determining a hydrogen concentration or hydrogen mixture concentration includes: an electrical conductor arrangement which is designed such that it can be brought into contact with the fluid mixture at least in part and is realized in the form of a voltage divider having two elements, the first element being a first conductor which, at least in a current-carrying state, has a resistance value which is different from that of the second element, 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 so as to determine the thermal conductivity of the hydrogen or hydrogen mixture by evaluating the bridge voltage using the 3-Omega method.

Abstract: A device for ascertaining a property of a fluid, having: an electric conductor assembly which is designed to be at least partly brought into contact with the fluid and which is designed as a voltage divider with two elements, wherein the first element is a first conductor which, at least in a current-conducting state, has a resistance value that differs from that of the second element; a measuring bridge with two voltage dividers connected in parallel, one of said voltage dividers being formed by the electric conductor assembly; an actuation unit for applying an AC voltage to the measuring bridge; a voltage detection unit for detecting a bridge voltage; and an analysis unit which is configured to ascertain a thermal conductivity as the property of the fluid by analyzing the bridge voltage using the 3-omega method.