What is the internal structure of the grid?

Structure of the grid:
The appearance of the grid plate is a flat plate with a thickness of 4~8mm. The internal structure is formed by the intersection of many thin lead strips. The two lead strips are filled with an X-ray permeable material and bonded together. The filler may be wood, paper or aluminum sheets or the like. Finally, the upper and lower sides are packaged with a thin aluminum plate to form a grid pattern. From the cross-section, the direction of the lead strips of the filter plates will gather a little. From the entire grid, there is a convergence line
specification:
parameter:

1 focal length: the vertical distance of the lead strip convergence line to the surface of the grid, f
2 grid ratio: also the ratio of the lead strip to the lead strip gap, R
3 grid density: the number of lead bars per unit distance, N
Exposure factor B:
It is generally considered that the exposure coefficient of the grid is one of the criteria for measuring a grid. The exposure coefficient B is the ratio of the exposure required to obtain the same density value when the grid is not used and the grid is used. Generally, between 2 and 6, the same performance of the filter B value is as small as possible, and in X-ray photography, the limb thickness is generally more than 15cm will use the grid.

Author：Alina