| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an ultrasound flaw detection method for steel sheets enabling high S/N ratios to be steadily obtained even during continuous flaw detection on line. <P>SOLUTION: In an ultrasound flaw detection method for steel sheets using a tire probe 10, transmission of ultrasound and sampling of waveform data on reflected waves are carried out three or more times while a steel sheet S travels a distance equal to the effective beam width of the ultrasound transmitted from the tire probe 10 to the steel sheet S, each of the absolute values of the data sampled three or more times is averaged for each period and further averaged over the same distance in the direction of the transmission of the ultrasound, and thereby the noise in each sampling data is suppressed and the position of any flaw in the steel sheet S is detected. Further, the averaged sampling data are stored in a buffer memory for each period of sampling. By reading and averaging the sampling data stored in the buffer memory for a period in which the steel sheet travels a distance equal to the effective beam width of the ultrasound, the data of a flaw is detected on a real time basis. <P>COPYRIGHT: (C)2012,JPO&INPIT |
