在射线数字平板直接成像（DR）检测技术和相控阵（PA）检测技术的理论基础上，通过对几种不同规格的小径管焊缝典型缺陷的检测对比来研究这两种新技术的差异，可看出DR技术和PA技术均能检出相关缺陷，总体来看，PA技术检出的缺陷长度略大一些。由于PA技术具有三维、3D成像等特点，其图像显示缺陷的信息更多，除了缺陷长度外，还能显示在基准灵敏度下的幅值、缺陷的自身高度，且通过设置焊缝坡口参数可实现3D动态成像，可更直观显示缺陷位置；而DR技术形成的缺陷形状更直观，更便于缺陷定性。

According to the principle of director digital panel radiography (DR) technique and ultrasonic phased array (PA) technique, the difference between these two new techniques can be obtained by comparing the typical defects of several different sizes of small diameter pipe welds. It can be concluded that DR technique and PA technique can detect the relevant defects on the whole, whereas the defect length given by PA was slightly oversized. As the PA technique is characteristic of 3D imaging, so its image display of defect can give more information. In addition to the length of the defect, the PA image also shows the amplitude of the reference sensitivity, the height of the defect, and it can achieve 3D dynamic imaging through setting the weld groove parameters, thus resulting in more intuitive display of defect location. On the other hand, the DR technique is to form more intuitive defect shape, and is easier to qualify the defect.