| 摘要 |
PURPOSE:To obtain a system which performs flaw detection automatically as to corrosion nearby the skirt base part of a cylinder and decides properly whether or not the cylinder is normal by deciding whether or not the depth and length of the corrosion measured by an ultrasonic probe are within a specific range. CONSTITUTION:While the cylinder 1 is rotated, the flaw detection is carried out as to a flaw detection area inside the skirt 2. The length of the corrosion in the circumferential direction is calculated by a corrosion state calculation processing block 11 by using the rotation of the cylinder 1 detected by a rotary encoder (RE) 8. Further, the depth of the corrosion is calculated by the block 11 by using the echo intensity of the ultrasonic wave from the main probe 6a and the length of the corrosion detected by the RE 8. Then a normal/abnormal decision processing block 12 decides that the cylinder is normal when the measured corrosion depth (ratio of corrosion depth to plate thickness) and corrosion length are within a nearly rectangular are encircled with constant corrosion depth D1 and constant corrosion length L1, and determines an abnormal area outside a border line which runs nearby coordinates (L1, D1) and reaches corrosion length L2 and corrosion depth D2. |
