观察、记录荧光屏上有无反射讯号和反射讯号的形态特征,出现在时间扫描线上的位置,是用 A 型探伤仪检测焊缝内部质量的依据。本文指出,清楚地了解焊接工艺规范以及与焊接有关的诸因素,确切分析讯号的来源,掌握它的变化规律,是对焊缝质量作出正确结论的重要环节。对10～40毫米厚钢板对接双面自动焊缝探伤中经常出现的假讯号进行了析别,分为六种类型。阐述了它们的产生原因,清除措施。并就假讯号与判伤之间的关系作了探讨。 Observe and record the morphological characteristics of the reflection and reflection signals on the fluorescent screen, which appear on the time-scan line, and are the basis for testing the internal quality of the weld with A type flaw detector. This paper points out that a clear understanding of the welding process specifications and welding related factors, the exact analysis of the source of the signal, to grasp its changing rules, is to weld the right to make an accurate conclusion an important part. On the 10 ~ 40 mm thick steel plate butt welding flaws often appear in the separation of the fake signals, divided into six types. Described the causes of their production, removal measures. And the relationship between the false signal and the judgment is discussed.