| 摘要 |
PURPOSE:To select a good material reliably, stably and in a non-destructive manner on the basis of whether a fitting stress of a double tube is a necessary value or not, by providing an appropriateness determinator which compares one or more signals out of ones corresponding to a waveform continuation time, a waveform area and a maximum amplitude value of a waveform of a signal processing device, with a set signal. CONSTITUTION:An elastic wave propagated in the direction of an arrow 5 is received by a reception converter 6 through a contact medium 2 and converted into an electric signal. This electric signal is subjected to an envelope detection processing by an AE measurer 7. An envelope detection waveform thus obtained is taken in an A/D converter in a signal processing device 8, AE waveform parameters are measured digitally in a sampling time of 100 usec, and based on the level thereof, it is judged by an appropriateness selector 9 whether fitting of inner and outer tubes is good or bad. According to this constitution, the precision in quality assurance of a double tube can be improved to a large extent. |
