A method for locating a wanted echo from unwanted echoes in a time-of-flight level measurement system

摘要

A series of pulses is transmitted to a surface of a material whose level is to be measured.;For each transmit pulse, received echoes (18, 19, 20) are converted into an echo function (17).;The time (t) following each transmit pulse is divided into time bins (22), and for each time bin (22) an echo function value is generated by which the echo function (17) exceeds a threshold.;The echo function values are stored in a two-dimensional pattern (24) whose dimensions are the number (n) of transmit pulses and the number (m) of time bins (22).;An image processing algorithm is applied to said pattern (24) for identifying clusters of similar echo function values forming trails (28, 29, 30).;On the basis of motion information on the level to be measured, one of said trails (28, 29, 30) is selected as a motion path of the wanted echo (25).