| 摘要 |
<p>PROBLEM TO BE SOLVED: To detect an undesired wall structure at a minimum cost of measuring techniques in order to take early measures for quality improvement. SOLUTION: A non-contact on-line type high temperature wall thickness measuring method is provided for detecting an undesired interior wall structure, such as a hexagonal hole in a hot rolled pipe, particularly a stretch reduced pipe. Using a laser ultrasonic method and at least one measuring head, the segment of the wall of the pipe to be measured during or immediately after a rolling process is circumferentially scanned, and in some cases the extended state of the wall of the pipe cross section is reproduced by a computer through mathematical analysis and symmetry consideration. When a plurality of circumferentially oscillating measuring heads are used, each of the measuring heads scans another allocated part of the pipe wall.</p> |
