Patent ID: 8354849

Claim:
A method for the measurement of humidity or density in a measurement target, with a microwave sender, a microwave receiver and an analysing unit, which can determine the phase and the amplitude for microwave radiation of the microwave sender received by the microwave receiver, and in which a complex-valued transfer function of the measurement arrangement can be stored, the method having the following steps: determining the phase and the amplitude of the microwave radiation transmitted through the measurement target for a number of frequencies in one measurement operation; calculating the complex-valued transmission function of the measurement target from the determined values using the complex-valued transfer function of the measurement arrangement; transforming the complex-valued transmission function of the measurement target into the time domain as a complex-valued time domain function; determining the point in time at which the amount of the main pulse has its maximum value as a first characteristic variable from the time domain function; determining a second characteristic variable wherein said second characteristic variable is selected from the following values: the width of the main pulse, the amplitude value of the main pulse and combinations of these values, and determining a density-independent humidity or a density of the measurement target depending on the first characteristic variable and the second characteristic variable.