这项工作的起因是因为我们面临着探测厚度达200毫米左右的焊缝。在大厚度焊缝的超声探伤工作中,由于在几十毫米到几百毫米的横波声程范围内都可能发现缺陷,而同一大小的缺陷随着距离不同,所产生的反射波幅度会有很大差别。因此要定量地表示缺陷的大小,就必需制作“距离-幅度”曲线来校正这种差别。但反射波幅度还与缺陷面积大小有关,因此还要从“面积-幅 The reason for this work is that we are faced with the detection of weld seams up to 200 mm in thickness. Ultrasonic flaw detection of large thick welds may cause defects in the range of tens to tens of millimeters of shear waves, and the amplitude of the reflected waves generated by the same size of flaw varies with the distance Big difference. Therefore, to quantitatively indicate the size of the defect, it is necessary to make a ”distance-amplitude" curve to correct this difference. However, the magnitude of the reflected wave is also related to the size of the defect area, so it is also necessary from the area