| 摘要 |
PURPOSE:To enable the dertermination of the phase of a repeating stress at which an AE (acoustic emission) wave is generated, by performing and resetting the measurement of phase information of the repeating stress at each cycle thereof to output phase information when the AE wave is generated. CONSTITUTION:When a stress signal is inputted into a comparator 1, a high level signal is outputted to a one-shot multivibrator 3 only while it is larger than threshold TH and the multivibrator 3 is triggered with the rising of the high level signal to obtain a one-shot pulse. A counter 5 is reset by the pulse to turn the contents to zero and advances by '+1' in response to a pulse from an oscillator 7. As an AE signal is outputted from a sensor 11, the contents of the counter 5 is latched with a latch 9 at the start of the rising thereof and thus, phase information of a repeated stress at the time point when the AE wave is generated is given.
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