HF Series Generators
Calibration
CA-1036R2
40
8. If the variation value is not ±0.2 of the Optical Density ( ±20% of Image
Gray Level / Dose Level with CR or DR) calculate the new value for the
AEC Tracking number in each Memory Location in the following manner:
G If the Optical Density at 55 kV has to be decreased and the Optical
Density above 70 kV has to be increased then increase the
Tracking value in one.
G If the Optical Density at 55 kV has to be increased and the Optical
Density above 70 kV has to be decreased then decrease the
Tracking value in one.
A tracking value of 10 w ill have no effect on AEC density (used in
solid state detectors).
a. Exit from the “Go to User Mode” screen by pressing the “Manual
Calibration” button and in calibration mode select the respective
Memory Location (E08, E10 or E24).
b. Values for AEC Tracking range is from --10 to +10. Determine the
correct value for the needed AEC Tracking change.
AEC-kV
TRACKING
CURVE
+10 +9 +8 +7 +6 +5 +4 +3 +2 +1
0
-- 1 -- 2 -- 3 -- 4 -- 5 -- 6 -- 7 -- 8 -- 9 -- 1 0
VALUE TO ENTER
IN THE MEMORY
LOCATION
10 9 8 7 6 5 4 3 2 1
0
255 254 253 252 251 250 249 248 247 246
c. Enter the new value and store it. Enter in user mode inside
calibration mode by pressing the “Go to User Mode” button and
repeat this process from step-7. until the desired density
compensation is obtained.
9. Insert a cassette with the Medium Film/Screen combination used by the
customer. Make an exposure at 110 kV (use the final Copper thickness
and the selected mA station noted before for 110 kV), develop the film
and measure the Optical Density obtained with those exposures. Check
that the film variation range is the same ±0.2 of the Optical Density
(±20% of Image Gray Level / Dose Level with CR or DR) obtained before
at 70 kV (Optical Density Adjustment -- Section 2.6.3). If the variation
value is not ±0.2 repeat step-8.
Calibration of AEC Tracking at 110 kV modifies the adjustment
done at 55 kV and 90 kV. Repeat exposures of step-7. and check
that they are correct.
In case that the AEC Tracking at 110 kV places the adjustment at
55 kV and 90 kV out of range, choose the AEC Tracking value
more convenient for the application.
Note .
Note .
To Next Page
Loading...