GE CT-9800 Technical Publications page 267

GE MEDICAL SYSTEMS
Rev. 16
7) Note the position of each film and remove all three pieces of film. Press heavily on the film and draw a
line on the film between the marks you made previously. This line must show on the film after it is
developed.
8) Place the films back in their positions on the detector. Verify the pencil marks of step 6 align with the
detector window. Secure with masking tape.
9) Be sure that no X-Ray exposures have been made for at least 5 minutes. The remainder of this
procedure must be done with a cold tube.
Enter CTDS
• (DC)
• (3)
• (180)
• (CR)(CR)
• (4)
• (3)
• (D)
• (20)
• (120)
• (10)
• (A)
• (500)
• (2500)
• (500)
• (2000)
• (1000)
• (2)
• (CR)(CR)(CR)
10) After the scan is completed, remove and develop the films. Be sure to mark them to remember their
relative positions.
11) Refer to Illustration 6-9-12. Make two lines on the exposed films: One line exactly 1/16 inch (1.6mm)
from the first line toward the gantry, another line exactly 1.24" (31.5mm) from the second line.
12) The center of the X-Ray beam must be toward the gantry on the detector window. The X-Ray beam
center (CL EXPOSURE) must be within 0.00472" to 0.03465" (0.12mm to 0.88mm) of the Detector
Window Center but displaced toward the Gantry, as shown in Illustration 6-9-12.
The difference between these centerlines is measured using a Vernier caliper or pocket comparator with
mm or inch scale reticle. Measure the two edges between the exposure and the window. If these
dimensions are XF(front) and XR(rear) the centerline difference is :
To meet specification and maintain that a shift toward the table is positive;
XF - XR = 0.04 ± 0.015 inches;
13) If adjustment is required, loosen all three sets of the detector lock nuts and mounting nuts, even if only
one or two need adjustment.
14) Loosen only the adjustment locking nuts (7/16") on the mounts which require adjustment.
Data Collection
X-Ray Tube Position
180 Degree Tube Position
To Down Load Position and return to Data Collection
Stationary X-Ray ON
Real Time Statistics
Default Rotor Speed
20 mA
120 KV
10 mm Aperture
Air Filter
X-Ray ON position
X-Ray OFF position
Trigger ON position
Number of triggers (2 second scan)
Trigger Frequency
Offset Correct & Normalize
Default filename & run description. Enter to continue.
XF - XR
2
or
6-9A-13
XF - XR = 1.0 + 0.4 mm
CT 9800 QUICK SYSTEM
Direction 18000