| 摘要 |
PURPOSE:To discriminate easily and exactly even in the case of a crack existing in the circumference of a weld, by deciding a mutual correlation function of an ultrasonic echo and a reference ultrasonic wave, and discriminating whether a defect exists or not, from the amount of its positive and negative side peak values. CONSTITUTION:A result of ultrasonic scanning of a body 3 to be inspected by a probe 1 is A/D-converted, and each waveform of an ultrasonic echo and a reference ultrasonic wave is stored in a waveform recording memory 4. In accordance with this stored contents, a self- correlation function and a mutual correlation function regarding the time of both the waveforms are operated and decided by a correlating part 5 of a correlation and operation processing device 9. Subsequently, positive and negative peak values of the mutual correlation function are detected by a peak value detecting part 6 and are inputted to an operation processing part 8 to calculate which peak value is larger, and in accordance with inversion of phase corresponding to the number of times of reflection of the ultrasonic echo, in case when the positive peak value is larger, it is decided to be a crack, and in case when the negative peak value is larger, it is decided to be other than a crack of dripping, etc. of welding. According to this constitution, even in the case of a crack in the circumference of a weld, it is discriminated easily and exactly. |
