| 摘要 |
PURPOSE:To detect an AE signal at a high accuracy and simply by a method wherein an acoustic emission (AE) signal is binary coded to perform a pulse counting so that only the AE signal is discriminated to make counts thereof significant. CONSTITUTION:An AE detector 1 converts an AE wave generating in a byte 3 into an electrical signal. The AE signal clear of noise is compared with the threshold voltage vO by a comparator 10. An event pulse generation circuit 12 outputs the first AE output signal of a group of the AE output signals when none of output signals from the comparator 10 arrives within the dead time. A timr 13 actuates a specified time counter 14 on this signal. When counts of the counter is between the upper and lower limit values set, the AE signal is determined to be significant and a pulse signal is outputted from a one-shot multivibrator 20. |
