CPI Indico 100 Series Service And Installation Manual page 159

CPI Canada Inc.
3D.5.0 AEC CALIBRATION (TABLE BUCKY) Cont
FILM SCREEN 1
FILM SCREEN 2
FILM SCREEN 3
EXIT
*TUBE?
50KV: 84.0:
55KV: 78.0:
65KV: 66.0:
75KV: 54.0
3200MS <<
*TUBE?
110KV: 34.0:
130KV: 28.0:
RLF COMPENSATION
MULT. SPOT COMP:
3200MS <<
Step
15.
16.
17.
18.
19.
20.
Millenia / Indico 100 Series Service Manual
The following screens are used for AEC calibration
* AEC CALIBRATION *
0%HU AEC CAL, F/S 1*
0%HU AEC CAL, F/S 1*
0%
75 KV KNEE BREAKPOINT CALIBRATION:
Select the table bucky image receptor.
Select the 75 kV knee breakpoint and enter the value 45 using the + or - buttons
adjacent to the LCD display.
Select the appropriate mA for the first film speed being calibrated per table 3D-13,
remembering that the slowest film screen used in that installation must be calibrated first
(example 320 mA for 100 speed film). Select large focus, center field.
Make an exposure and note the dose and mAs.
Referring to table 3D-12, select the estimated dose required for the film speed being
calibrated i.e. 1025 ± 25 µR (see note on next page regarding conversion of µR to µGy if
desired) at the 75 kV knee breakpoint for 100 speed film.
Note that the dose values in the table are based on the R-probe being located at
the film plane. If the probe was placed in front of the grid the dose values shown
in the tables must be increased accordingly. The dose in front of the grid will
typically be approximately double the dose at the film plane.
Adjust the required gain potentiometer on the AEC board (see note below) while taking
exposures until the dose noted in the previous step is obtained.
•
CHANNEL 1 ON THE AEC BOARD IS TYPICALLY USED FOR THE TABLE
BUCKY AEC CHAMBER. YOUR INSTALLATION MAY USE A DIFFERENT
CHANNEL ON THE AEC BOARD.
•
REFER TO TABLE 3D-10 FOR THE AEC BOARD GAIN POTENTIOMETER
(GAIN POT) DESIGNATIONS FOR THE VARIOUS AEC BOARDS.
DENSITY SETUP
>>
Action
Ch # 740904-06 Rev. D
AEC Calibration
85KV: 42.8
95KV: 38.0
+
-
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3D
Page 3D-25