| 摘要 |
PURPOSE:To decrease the amt. of the data for discriminating wall thickness and to perform discrimination with high accuracy by determining the average value of the data for measuring the wall thickness at pural measurement points in each block of the circumference of a pipe body and utilizing the max. value, min. value and reference wall thickness value at each average value. CONSTITUTION:Ultrasonic probes 2 ae disposed so as to face to each other on the circumferential face of a steel pipe 1, and pulses are intermittently irradiated onto the circumferential side face of the pipe 1 from the probes 2. The relfected waves thereof are received with the probes 2, whereby the wall thickness of the pipe 1 is measured. The pipe 1 is conveyed in this stage and is scanned spirally at a prescribed pitch. The circumference of the pipe 1 is divided by N, and the data for measuring the wall thickness for each of respective sections l1-lN is summarized and the averae values T1-TN thereof are determined. The values that exhibit abnormal values with respect to the reference wall thickness value determined with respect to the pipe 1 among the average values T1-TN are excluded, and the remaining max. value and min. value are drawn. Whether the wall thickness and thickness deviation at the circumference of the pipe 1 are good or not is discriminated from the max. value, the min. value and the reference wall thickness value. |
