| 摘要 |
PURPOSE:To discriminate features measured of a defect, by measuring the intensity of two frequency components respectively above and below a peak frequency value within a frequency band of a received reflected wave. CONSTITUTION:A focus converging type ultrasonic probe 3 of an ultrasonic inspection mechanism 21 moves in directions X and Y with a scanner 4 under the control of an ultrasonic inspection mechanism control section 22 to scan an object 2 to be inspected. A pulse receiver 10 of the control section 22 receives a signal from the probe 3 to display a received waveform thereof on an oscilloscope 11 while being sent to an image processor 23 via a gate circuit 12 and an A/D converter 14. A microprocessor 15 of the device 23 performs a Fourier transform of an input signal to extract two frequency component values respectively above and below a peak frequency value. Then, a difference between the component values or the sum thereof is determined. The value thus obtained varies with the form of a defect, thereby enabling discrimination of features of a defect. |
