Integrated microstructural sensor element for detecting thermodynamic variables of a fluid.

摘要

An integrated microstructural sensor element 5 for detecting thermodynamic measured variables of a fluid. For this purpose a carrying member 16, in particular a board or a wafer, with at least one microstructural heating element 15 which is in contact with the fluid during operation, is provided on which or in the vicinity of which first means 20, 21 are arranged for at least temporary charging of the heating element 15 with an electric alternating current of defined frequency or of a defined frequency band and further means 22, 23, 24 are arranged for detecting the amplitude of the third harmonic of the electric voltage applied to the heating element 15. The proposed microstructural sensor element 5 in the form of a compact, integrated component is particularly suitable for determining or monitoring the thermal conductivity and/or the thermal capacity of a fluid, in particular an oil in a motor vehicle.