Method for determining the fill level of a medium and corresponding device

摘要

A method for determining the fill level of a medium, wherein a transmission signal is transmitted, a return signal is received, and the return signal is evaluated in view of the process variable in a manner which allows a general and flexible handling of interfering signals in the received signals. This result is obtained by filtering at least one of the return signal, a signal derived from the return signal and an envelope curve formed from the return signal into at least one sub-signal, and using said at least one sub-signal for evaluating the return signal for at least determining the fill level.

主权项

1. A method for determining the fill level of a medium according to the transit time method, comprising the steps of:
transmitting at least one transmission signal, receiving at least one return signal, and evaluating said return signal determining the fill level, wherein evaluating said return signal comprises the following steps: applying a Fourier Transformation to said return signal, frequency filtering said Fourier transformed return signal into sub-signals by breaking down the Fourier transformed return signal into sub-signals on the basis of frequency, applying an inverse Fourier Transformation to said sub-signals, identifying at least one partial signal within said inverse Fourier transformed sub-signals, classifying said at least one identified partial signal as one of an echo signal or an interference signal, evaluating a respective probability of reliability of identification and of classification of the partial signals identified within the sub-signals, and combining information about the at least one identified partial signal of the sub-signals, information about the classification of the at least one identified partial signal, and respective probabilities of reliability of identification and of classification for determining the fill level of the medium.