Test Patterns

Star X-Ray Test Patterns for measuring Focal Spot size

Shown in 07-509-2000

Focal spot size can be determined by observing the regions of blurring which occur when the pattern is radiographed by an x-ray source of finite dimensions. Radiation from different areas of the focal spot will cause a periodic blurring of the pattern due to penumbra effects. Knowledge of the geometric factors, and the distance from the center of the pattern to the region where blurring occurs, will permit the calculation of the focal spot size with the same accuracy as measurements made with a pinhole camera.

Ultra-high Precision Test Pattern for measuring modulation transfer function

Shown in 07-553

The Ultra-High Precision Test Pattern was developed especially for determining the modulation transfer function. It utilizes 22 groups of line pairs. Each group is indicated by the extended line above the pattern. The resolution of the individual groups can be taken from the table. Lead thickness is 0.05 mm. Pattern size is 71 x 44 mm.

Test Patterns for measuring resolution

The choice of pattern depends on the specific application. The sector test patterns are 0.4°, and the group test patterns have varying numbers of line pair groups. Lead thicknesses are limited by the resolution, with a maximum thickness of 0.1 mm for test patterns up to 5 LP/mm. Radiopaque numbers indicate the resolution (in LP/mm) of each group.
Shown in 07-501-2000	Shown in 07-515
Shown in 07-527	Shown in 07-541-2000

X-Ray Test Patterns for measuring resolution of image intensifiers and video systems

Shown in 07-537

These Ultra-High Precision patterns contain two line groups of each resolution value; the groups are perpendicular to each other. The patterns are recommended when screen image or video intensifiers are to be tested. They are ideal to place in various locations covering the entire area of an image intensifier.