Patent ID: 8931339
Filing Date: 2015-01-13
Classification: G01F,G01S

Abstract:
1. A method for evaluating measurement signals of a measurement curve of a fill level measurement device operating on a travel time principle and serving for measuring the fill level of a medium in a container, which method comprises the steps of: using the fill level measurement device operating on a travel time principle to perform the steps of: obtaining reference signals data as a function of the travel time of the signals, whereby the reference signals data are obtained by at least one known measurement curve or determined from known measurement-specific or container-specific data; obtaining at least one current measurement curve composed of current measurement signals along a measurement distance; comparing the current measurement curve, or selected data of the current measurement curve, with corresponding reference signal data and identifying interference signals and a useful signal, if available, among the current measurement signals; weighting information from said identified interference signals and/or said useful signal, if available; selecting a measurement curve obtained at an earlier point in time showing said interference signals and a useful signal; determining the displacement of said interference signals between said selected measurement curve and the current measurement curve; for the case that no useful signal can be found in the current measurement curve, determining said interference signals, which correspond to a known location of the container or the measurement device located in the medium; and determining a current unknown fill level by the aid of the displacement of said interference signals between a first point in time and a current point in time and said useful signal obtained at the earlier point in time, determining current unknown fill level L(2) at a time t(2), with reference to the known location x(0) of an Installation or part of the measurement device causing said interference signals, from interference signals determined for this location x(0) of the container or the measurement device to be at a place x(1), at a time t(1) that is earlier than the time t(2), a fill level L(1) determined at the same time t(1) from a useful signal, and a position x(2) at time t(2) of said interference signals in an current measurement curve, according to the formula