| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an ultrasonic flaw detector, capable of stably detecting the flaw present in a metal strip which is fed continuously. SOLUTION: The flaw of a steel strip 16 is inspected continuously by the ultrasonic flaw detector, while the steel strip 16 is fed continuously. A liquid tank 8 housing water 11, feed rolls for guiding the steel strip 16 to pass the same through the water 11 and the transmission type ultrasonic flaw detector for performing flaw detection according to a pulse reflecting method to inspect the part of the steel strip 16 immersed in the water 11 by the sensor part A arranged in the water 11 are provided. When reflected waves F1, F2 are prescribed threshold or higher, it is decided that there is a flaw. At this time, the threshold are appropriately corrected, on the basis of the water temperature in the vicinity of the sensor part A measured by a thermometer 30.</p> |
