通过分析透射电子显微镜的曝光机理, 得出了荧光屏亮度与曝光时间之间的关系表达式。设计了TDX-200透射电子显微镜自动曝光电路, 并通过实验对自动曝光参数进行了标定。通过对多种实际样品在不同工作模式下进行自动曝光试验, 得到了相对清晰的电子显微像。结果表明, TDX-200透射电子显微镜自动曝光的设计满足要求。

By studying the exposure principle applied to transmission electron microscopy (TEM), the relational expression between current density on fluorescent screen and exposure time is deduced. The automatic exposure circuit of TDX-200 TEM is designed and the parameter value in expression is gained by the exposure experimentation with the master sample on the TDX-200 TEM. As a result, on the TDX-200 TEM, the automatic exposure experimentation on some samples is completed on the different operating modes, finally the relatively clear-cut TEM images are formed. The experimentation results indicate that the design of automatic exposure is valid.