Method for fill level measurement using the travel time principle
First Claim
1. A method for measuring a fill level of a fill substance in a container with a fill-level measuring device working according to a travel time principle, comprising steps of:
- the fill-level measuring device in measurement operation sends transmission signals toward the fill substance in the container, detects signal fractions reflected back in the container and, based on the signal fractions reflected back in the container, derives echo functions, which give amplitudes of the signal fractions as a function of their travel time, with assistance of a table, wherein;
rows of the table correspond to discrete fill levels and columns of the table correspond to discrete travel times;
information is stored as historical measurement points, in each case, in that row, whose row index corresponds to the associated fill level, and information derived from past echo functions concerning travel times of echo function maxima attributed to reflections on reflectors located in the container;
the table is continuously updated based on current echo functions derived in ongoing measurement operation;
information derived from current echo functions concerning travel times of echo function maxima attributed to reflections on reflectors located in the container are stored as current measurement points, in each case, in that row, whose row index corresponds to the associated fill level ascertained by the fill-level measuring device;
a plausibility check is performed;
historical and current measurement points recognized as implausible due to the plausibility check are deleted and all remaining current measurement points are adopted into the table as historical measurement points, andcarrying out a subsequent fill level measurement by subsequently sending transmission signals toward the fill substance in the container, detecting signal fractions reflected back in the container, obtaining a subsequent echo function, and determining the fill level by comparing the subsequently-obtained echo function with the information adopted into the table as historical measurement points, based on a greatest agreement between the subsequently-obtained echo function and the information adopted into the table.
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Accused Products
Abstract
A method for measuring a fill level of a fill substance in a container with a fill-level measuring device working according to the travel time principle. The fill-level measuring device in measurement operation sends transmission signals toward the fill substance in the container and, based on their signal fractions reflected back in the container, derives echo functions, which give the amplitudes of the signal fractions as a function of their travel time. With the assistance of a table, whose rows correspond to discrete fill levels and whose columns correspond to discrete travel times, and in which are stored as historical measurement points, in each case, in that row, whose row index corresponds to the associated fill level, information derived from echo functions derived in the past concerning travel times of echo function maxima attributed to reflections on reflectors located in the container, that also delivers reliable measurement results, when measuring conditions at the location of use of the fill-level measuring device can change, wherein the table is continuously updated based on current echo functions derived in ongoing measurement operation, wherein current measurement points derived from current echo functions are stored.
36 Citations
11 Claims
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1. A method for measuring a fill level of a fill substance in a container with a fill-level measuring device working according to a travel time principle, comprising steps of:
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the fill-level measuring device in measurement operation sends transmission signals toward the fill substance in the container, detects signal fractions reflected back in the container and, based on the signal fractions reflected back in the container, derives echo functions, which give amplitudes of the signal fractions as a function of their travel time, with assistance of a table, wherein; rows of the table correspond to discrete fill levels and columns of the table correspond to discrete travel times; information is stored as historical measurement points, in each case, in that row, whose row index corresponds to the associated fill level, and information derived from past echo functions concerning travel times of echo function maxima attributed to reflections on reflectors located in the container; the table is continuously updated based on current echo functions derived in ongoing measurement operation; information derived from current echo functions concerning travel times of echo function maxima attributed to reflections on reflectors located in the container are stored as current measurement points, in each case, in that row, whose row index corresponds to the associated fill level ascertained by the fill-level measuring device; a plausibility check is performed; historical and current measurement points recognized as implausible due to the plausibility check are deleted and all remaining current measurement points are adopted into the table as historical measurement points, and carrying out a subsequent fill level measurement by subsequently sending transmission signals toward the fill substance in the container, detecting signal fractions reflected back in the container, obtaining a subsequent echo function, and determining the fill level by comparing the subsequently-obtained echo function with the information adopted into the table as historical measurement points, based on a greatest agreement between the subsequently-obtained echo function and the information adopted into the table. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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Specification