| 摘要 |
PROBLEM TO BE SOLVED: To identify a defect echo and a pseudo echo by processing a flaw detection signal that is obtained by scanning the surface of a specimen with a probe back and forth using the split spectrum processing method(SSP) and obtaining the appearance length of an instruction, and comparing it with a specific value. SOLUTION: The surface of a specimen is scanned by a probe with specific flaw detection conditions, namely a longitudinal wave of 36 degrees and a frequency of 1 MHz, back and forth, thus detecting its flaw. Then, the detected original flaw detection signal (RF signal) is subjected to SSP processing, thus obtaining the appearance length of an instruction when the probe is scanned back and forth. In this case, the appearance length of the instruction of a pseudo echo becomes approximately 1/2 that of the instruction of a defect echo. Therefore, it is compared with a specific preset value. Then, when the appearance length of the instruction is shorter and longer than the specific value, it is judged as the pseudo echo and the defect echo, respectively, thus easily identifying the defect echo and the pseudo echo in the flaw detection of piping or the like consisting of an Austenite stainless steel casing material. |
