Patent ID: 7819002

Claim:
A method for measuring a fill level of a fill substance in a container using a fill level measuring device operating according to a travel-time principle, comprising the steps of: sending periodic transmission signals toward the fill substance; registering and converting their echo signals into an echo function; and determining at least one echo characteristic of the echo function, and, on the basis of echo characteristics of at least one preceding measurement, a prediction is derived for echo characteristics to be expected in the case of a current measurement, the echo characteristics include travel-time of maxima of the echo function, especially a maxima of fill substance surface, a maxima of a floor of the container or maxima of a fixedly installed disturbance on the basis of travel-time of at least one maximum of a previous measurement, a prediction is made for travel-time of a corresponding maximum to be expected in the case of the current measurement, wherein: the prediction is made for travel-time of the maxima by calculating an instantaneous acceleration and an instantaneous rate of change of the travel-time on the basis of at least three preceding measurements, and the travel-time to be expected is extrapolated on the basis of the acceleration and the rate of change; echo characteristics of the current measurement are determined, taking into consideration the prediction; and on the basis of the echo characteristics, the current fill level is determined.