| 摘要 |
PURPOSE:To provide an AE propagation speed measuring instrument which can measure the propagation speed of AE (Acoustic emission) propagated by a specimen accurately even if the AE is a surface acoustic wave. CONSTITUTION:The title device consists of a piezoelectric element which resonates at a frequency band of destruction AE generated when a substance made of the same material as that of a specimen 1 breaks and is provided with a transmission sensor 2 mounted to a specific position of the specimen 1, a reception sensor 3, and a waveform memory 8 where a drive waveform for driving the transmission sensor 2 is stored. Further, it is provided with a waveform memory 12 for recording the waveform of the AE signal output from the reception sensor 3 and a central processing unit 13 for calculating the waveform phase difference between the drive waveform and AE signal waveform and then calculating the propagation speed of AE which is propagated through the specimen 1 according to the waveform phase difference and the distance between the transmission sensor 2 and the reception sensor 3. |
