球罐γ源偏心局部曝光的焦距选择

Focal setting of eccentricity partial exposure of gamma ray source photographic inspection for spherical tanks

本文根据JB4730－94压力容器无损检测的有关规定推导出球罐γ源偏心局部曝光的焦距选择公式，并对关键性技术问题进行阐述分析，强调焦距选择的重要性和实际选择方法。

This paper gives the formula of focal setting of eccentricity partial exposure of gamma ray source photographic inspection for spherical tanks according to the specification JB4730-94 for inspection of pressure vessels, analysises the key technical problems and emphasizes the importance of focal setting.