为了了解平板对接焊缝射线检测中管电压对散射比的影响，并更好地保证底片影像质量，在其他透照参数不变的情况下，通过改变管电压来研究散射比的变化规律。结果表明：在管电流、曝光时间和焦距等参数相同的条件下，随着管电压的增加，散射比呈减小的趋势。试验为平板对接焊缝射线检测中管电压的选取提供了参考依据。

In order to analyze the voltage effect on scattering ratio in radiographic testing for plate butt welds, so as to better guarantee the image quality of film, in this paper, the variation of scattering ratio is experimented by changing the voltage under the condition of other parameters being invariant. The results show that the scattering ratio decreases with the increase of the tube voltage when the parameters such as tube current, exposure time and focal length are fixed. The experiment provides a reference for the selection of tube voltage in the radiographic testing for plate butt welds.