| 摘要 |
PURPOSE:To make the measurement of the parameter of an AE wave shape accurate and perform more exact evaluation of defects and optimize monitoring of soundness and safety of a construction by forming an event pulse that is different from a received signal of an AE wave and selecting either one of them. CONSTITUTION:A preamplifier 4 and main amplifier 5 amplify the received signal of an AE sensor 6 and give it to envelope line treatment circuit 7 and 8. Both circuits have different time constants, and both formed envelope curve signals are given to event making circuits 9 and 10, and if they are over a certain level, an event pulse of logic ''1'' is formed and it is supplied to a pulse selecting circuit 11. If, in the circuit 11, a pulse EVo is logic ''1'' and it is over a certain pulse of a pulse EVn in a certain time after the period of the rise time of EVo, the delay signal for the pulse EVo is output to a signal handling circuit 12. As a result, the parameter of the AE wave shape can be measured accurately. |
