CPI Canada Inc.
AEC Calibration
3D
Millenia / Indico 100 Series Service Manual Ch # 740904-06 Rev. D
Page 3D-23
3D.5.0 AEC CALIBRATION (TABLE BUCKY)
Figure 3D-13: Equipment setup for table bucky AEC calibration
Step
Action
SETUP FOR AEC CALIBRATION
IF THE AEC BOARD BEING CALIBRATED HAS SHORT AEC TIME COMPENSATION
(FIGURE 3D-9 OR 3D-11), THE SHORT EXPOSURE TIME COMPENSATION MUST FIRST BE
DISABLED.
TO DO THIS, ADJUST ALL SHORT AEC EXPOSURE TIME COMPENSATION
POTENTIOMETERS TO ZERO, IE SUCH THAT THE WIPERS ON EACH POT ARE GROUNDED.
VERIFY THE CORRECT SETTINGS BY USING AN OHMETER ON LOW OHMS RANGE AND
ENSURING A NEAR ZERO OHMS READING FROM THE WIPER OF EACH SHORT AEC TIME
COMPENSATION POT TO GROUND. REFER TO TABLE 3D-11 FOR THE SHORT AEC TIME
COMPENSATION POTENTIOMETER DESIGNATIONS.
FAILURE TO PRESET THESE POTS WILL RESULT IN DIFFICULTY IN PERFORMING
AEC CALIBRATION.
1.
Set up the X-ray tube stand as shown in figure 3D-13.
2.
Align the tube stand and table bucky such that the central ray is centered relative to the
image receptor.
3.
Open up the collimator to expose all three fields of the AEC pickup. Ensure that the
central ray remains centered relative to the image receptor.
4.
Place the R probe at the film plane, i.e. behind the grid. If this cannot be done, then place
the probe on the table top. Ensure that the R-probe is located as close as possible to the
central ray, but not blocking any pickup areas on the AEC device. The R meter must be
set to measure in the micro-R range.
