| 摘要 |
<p>An ultrasonic flaw detector comprising a probe which is driven by a signal to emit ultrasonic pulses obliquely to the surface of a sample and receive echoes from defects in the sample; and a scanning mechanism which moves the probe over a predetermined scanning range on the sample and outputs a spatial position of the probe. The detector further comprises a transmitter-receiver which includes a transmitter unit for transmitting signals to the probe, a receiver unit for receiving echoes through the probe, a position detector unit for inputting a spatial position of the probe from the scanning mechanism, and a signal processing unit for detecting defects based upon the stored spatial position of the probe and the stored echoes by taking into consideration the expansion of the ultrasonic beam caused by diffraction. It is possible to improve the precision of checking the samples using ultrasonic waves, and to detect and accurately measure the shapes, sizes and positions of acoustically discrete portions (defects).</p> |
