CPI Canada Inc.
AEC Calibration
3D
Millenia / Indico 100 Series Service Manual Ch # 740904-06 Rev. D
Page 3D-33
3D.7.0 AEC DENSITY CALIBRATION (Cont)
DENSITY
STEP
CALIBRATION NUMBER (- 8
DENSITY = HALF THE DOSE, +8
DENSITY = DOUBLE THE DOSE)
DENSITY
STEP
CALIBRATION NUMBER (- 5
DENSITY = HALF THE DOSE, +5
DENSITY = DOUBLE THE DOSE)
-8 50
-7 44
-6 38
-5 31
-5 50
-4 25
-4 40
-3 19
-3 30
-2 13
-2 20
-1 6
-1 10
0 DENSITY: SHOWN FOR REFERENCE ONLY.
+1 13
+1 20
+2 25
+2 40
+3 38
+3 60
+4 50
+4 80
+5 63
+5 99
+6 75
+7 88
+8 99
Table 3D-15: Example density values
Step
Action
1.
Reselect FILM SCREEN 1. Replace the absorber previously used for kV breakpoint
calibration with the 1.5 mm thick copper absorber.
2.
Reselect the 75 kV knee breakpoint.
3.
Select << to return to the AEC CALIBRATION menu.
4.
Select DENSITY SETUP.
5.
Referring to table 3D-14, note the dose at 75 kV for film screen 1. This will be referred to
as the 0 density dose.
6.
Select the highest density minus step desired i.e. - 8 from the density setup menu. If it is
not intended to use this step, select the highest density minus step to be used i.e. - 5,
then set the unused steps to - to disable those steps. To disable density steps, press the
- button to scroll down until the - symbol is displayed.
7.
Set the calibration number for the highest density minus step to the desired relative
density value (example 50, this will give approximately 1/2 the 0 density dose).
8.
Make an exposure and confirm that the measured dose is approximately the desired
value.
9.
If the measured dose is not as expected, adjust the calibration number for that density
step and repeat step 8.
10.
Select the next density step (i.e. - 7) and enter the appropriate calibration number for that
step. Refer to table 3D-15 and the notes preceding table 3D-15. Repeat steps 8 and 9.
11.
Repeat the previous step for each remaining density minus step. Use the >> and <<
buttons to navigate through the DENS SETUP menu in order to access all the density
steps in this procedure.
