| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain a measuring method in which the distance up to the surface of the contents in a container, from an antenna can be measured by finding an interval value situated in the center of an interval value belonging to the maximum value and the minimum value of the grade of an echo profile. SOLUTION: When the level of the contents in a container is low, reflected waves E1 from the surface of the contents and reflected waves E2 from the bottom part of the container reach an antenna at a slight transmission difference corresponding to the interval between the surface of the contents and the bottom part of the container. As a result, they are overlapped with each other, and a double-profile mountain- shaped elevation part Ed is formed, the reflected waves E1 cannot be discriminated, and a measuring error is generated. Then, a grade maximum value m1 which is closest to the maximum value of an echo profile and its interval value X1 , a grade minimum value m2 which is closest to the maximum value m1 and its interval value X2 as well as agrade maximum value m3 which is closest to the grade minimum value m2 and its interval value X3 are found. Then, when a quotient Q (m2 /m1 ) is smaller than a reference value, the interval value XM (the distance between the antenna and the surface of the contents) of the peak value (amplitude AM) of the reflected waves E1 is found by an expression XM=X2 -0.5.(X2 -X3 ).</p> |
