The application on X-ray focal length parameter selection in the visualization nondestructive testing

Considering the important position in the power grid of GIS equipment. Yunnan power Grid has taken the lead to put X-ray digital representation technological in the application of Visualization Nondestructive Testing. But now, the application of X-ray used in electrical equipment is still at the beginning, there is still no field investigation operation rules, standards for X-ray machines to chose, image processing system and other theory foundations. The article based on a goodly amount of field investigation and also a lot of calculations, and put forward a theory about the selection method of X-ray exposure parameter in the application of Visualization Nondestructive Testing. (authors)