Design and realization of automatic exposure of TDX-200 transmission electron microscopy

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.