Fluke Biomedical 07-501 - Manual (Page 5)

Introduction
X-Ray Test Patterns
1
1-1
Section 1
Introduction
1.1 X-Ray Test Patterns
These x-ray test patterns are used to evaluate film screen systems and magnification techniques. The
patterns consist of various lead thicknesses. Each test pattern is enclosed in plastic. The resolution range
for each pattern is different. On the face of each pattern is the range of line pairs per mm for easy
identification.
1.2 Film/Screen Resolution Limits
1. Place the test plate on top of a test film. Do not use a grid.
2. Use a 40" focus-film distance and 50-60 kVp. Center the tube over the test plate. Adjust the mAs for a
gross optical density of about 1.5 on a portion of the film not covered by the test plate. (These factors
give minimum geometric effects and sufficient contrast to assure a reliable test.)
3. Determine the limiting resolution by inspecting the finished radiograph with a 5-10 power magnifying
glass. This is done by looking for the last bar section in which you can clearly see a distinction
between line and space. Read the number corresponding to this line pair section. This represents the
line pair resolution for your system.
4. Additional testing can be made by placing tissue equivalent material over the test pattern. This is
done to evaluate how well the x-ray system can resolve through attenuation.
1.3 Models
07-501
07-521
07-525
07-547
07-555
07-515
07-523
07-539