NOTE:
The point of the scale that is in sharpest focus should be the same regardless
of the quadrant in which the test device was imaged. The tomographic cut
plane should be flat to within plus or minus 2 mm. For linear equipment, this
tolerance may have to be expanded to plus or minus 3 mm.
6-29. PREVENTIVE MAINTENANCE
This test should be performed:
a. At six-month intervals
b. After any service has been performed on the tomographic drive mechanism.
6-30. CORRECTIVE MAINTENANCE
Any non-uniformity in the cut plane flatness requires correction. Call a service
representative or engineer for system adjustment.
Section VI. RESOLUTION TEST
6-31. PURPOSE
The resolution test determines the resolution (detail) capability of the system in
the plane of cut.
6-32. EQUIPMENT/MATERIAL
a. Tomographic resolution test object.
b. Plexiglas spacers 5 cm thick and attenuator blocks.
c. One 8- x 10-inch cassette.
d. Record data form.
6-33. PROCEDURE
a. Prepare the system for the operation.
b. Select the most commonly used:
(1)
Tomographic motion.
(2)
Sweep speed.
(3)
Exposure angle.
MD0062
6-23