| 摘要 |
PURPOSE:To detect easily and accurately a defect in an inspected body. CONSTITUTION:A transmitting/receiving device 2 for generating pulses and amplifying echoes is connected to a transducer 1 that transmits pulses to an inspected body M and receives echoes, and to the rear part of the device 2, a gate circuit 3 for taking out an echo of a free interval from among echoes is connected. Also, a positive comparator 4, a negative comparator 5, a positive peak holder 6 and a negative peak holder 7 are connected to the gate circuit 3, and these outputs are inputted into a controller 9. At the positive comparator 4 and the negative comparator 5, the timing of the earliest echo from among echoes that surpass for the first time a reference value set beforehand, is inputted into a delay circuit 8, and the gate circuit 3 is closed after a time that is approximately enough for one period. |
