| 摘要 |
PURPOSE:To output a desired discrimination signal simply by an analog processing while reducing the number of components, by enabling execution of output corresponding to the amplitude of an output signal by inputting an output of an integration circuit to a plurality of comparators which have reference values being different in amplitude. CONSTITUTION:An impact force of a hammer 10 is conducted to a member 30 to be inspected, through a contactor 26, and a counter-force of impact is given to the contactor 26. When a signal V detected by a sensor 32 is inputted to a determination circuit 34, a noise part is cut off by a comparator 36 and a rectangular pulse signal V1 corresponding to the width of a waveform pulse is outputted therefrom. Moreover, this pulse signal V1 is inputted to an attenuator 38 and a rectangular pulse signal V2, attenuated so to be outputted with the sensitivity corresponding to the member 30 to be inspected is outputted therefrom. This signal V2 is integrated in an integration circuit 40, an integration signal V3 corresponding to the pulse width is compared with reference voltages V02 and V03 in comparators 42 and 44 and when these threshold values are exceeded, display means 46 and 48 are lighted. |
