| 摘要 |
PURPOSE:To measure the position of a flaw at a high accuracy by integrating a sampling signal of a reflected echo following a phase detection thereof to accurately determine the peak position and peak voltage of the echo. CONSTITUTION:A high frequency sine wave outputted from a frequency totalizer 6 is devided down to a desired frequency with a division circuit 7 to drive a pulse generator 9 with the division output as gate signal, which applies a pulse voltage to a transducer 10. A reflected echo from flaw or the like in an object to be inspected is converted into an electrical signal with the transducer 10 again and inputted into a sampling circuit 13 through an amplifier 12. In the sampling circuit 13, a delay pulse generated from a delay circuit 8 is delayed in proportion to the amplitude of a reference sine wave signal outputted from a phase detection circuit 14 to perform a sampling. The delay time of the delay pulse is controlled with a computer 15 in such a manner that the integration of the output of the phase detection circuit 14 is 0V to determine the peak position of the reflected echo. |
