通过设计虚拟聚焦试验，验证了超声相控阵检测对各个阵元信号进行合成后的A扫信号具有更高的信噪比，从而在使用A扫信号进行成像时，可以提高图像的分辨率，使得缺陷的成像质量更高；更进一步地说明了阵元越多，能够得到试件的信息越多，利用信息形成的图像质量也就越高，检测结果就会更加接近缺陷的真实情况。

Based on designing a virtual focusing experiment, it is approved that composite A-scan signal has high S/N ratio, thus the quality of the image of specimen is improved due to high resolution. It is also explained that the more elements the transducer has, the more information about the specimen can be gotten. So the image is closer to the true face of the defect due to high quality.