| 摘要 |
PURPOSE:To perform continuous thickness deviation detection accurately and rapidly over the overall length and overall circumference of a pipe by scanning an ultrasonic probe on the external circumference of the pipe to be checked closely spirally and by continuously calculating the difference between the maximum thickness and minimum thickness of the pipe on every one-round scan. CONSTITUTION:While the probe of a pulse reflection type ultrasonic thickness gauge 1 is moved axially along the external circumference of a pipe to be checked, the pipe is revolved to scan the probe on the external circumference of the pipe closely and spirally. A thickness deviation operator 4, synchronizing with every one-round scan on the pipe through a probe rotation detector 11, calculates the difference between storage contents of maximum and minimum thickness storage devices 2 and 3 to calculate the thickness continuously. This thickness deviation is compared with the contents of a thickness deviation value setter 6 and an abnormal thickness deviation part counter 7 counts the frequency of positions of thickness deviation exceeding a prescribed value, so that when the thickness deviation exceeds the set value >=3 times continuously, an alarm is sent from an alarm device 10 through a comparison part 8. Thus, the continuous thickness deviation detection is performed rapidly and accurately over the overall circumference and overall length. |
