| 摘要 |
<p>PROBLEM TO BE SOLVED: To enable highly accurate and stable on-line measurement by determining whether a measurement value obtained by an immersion ultrasonic board thickness meter movably provided in a widthwise direction of a plate is normal or abnormal based on a measurement value of a radioactive transmission board thickness meter provided at a center position of a plate width. SOLUTION: A shift in lengthwise position of respective board thickness meters for thickness t0 measured by radioactive transmission board thickness meters 2, 3 for measuring a thickness at a center position of a plate width and thickness ta to td measured by an immersion ultrasonic board thickness meter 4 (4a to 4d) is corrected by tracking according to a travel speed of a steel plate to the board thickness meter positioned most downstream. Each thickness measurement value after tracking is subject to smoothing to remove a fluctuation in high frequency components. Each thickness t0 ', ta ' to td ' after smoothing is input to a board thickness abnormality determining apparatus 9, where it is compared for each timing to eliminate abnormal values of the board thickness meter 4. Thickness t0 ' at the center of the plate width and thickness values ta0 to td0 after abnormality determination are input to a board thickness profile calculating device 10 for obtaining a predetermined board thickness profile measurement value.</p> |
