Revision W HF Series X-ray Generators - Service Manual
A-10 Quantum Medical Imaging, LLC
Appendix A AEC Calibration with DR or CR Film Plate
16. The AEC KV Calibration screen is displayed.
Figure A-3. AEC KV Calibration Screen
17. There are a total of six kV calibration points for a 125 kV system (50,
60, 80, 100, 110, and 120 kV); 150 kV systems require an additional
two kV calibration points (130 and 140 kV). The image receptor and
chamber field settings remain the same as those used in the AEC
Optical Density Calibration procedure.
18. Place indicated thickness of acrylic (5 CM for first calibration point) in
the X-ray beam.
19. Insert a CR film plate and collimate down to film size.
20. Take an exposure at the setting indicated in the center display box
(i.e., 50 kVp, 200L mA).
21. Process the CR film plate (if CR system) to determine sensitivity
value.
a. If the sensitivity value is within acceptable range as defined by
manufacturer, press the Measured OD field up or down adjust-
ment keys to set the Measured OD value to Base Optical
Optical Density setting (1.3, see Figure A-2). Press the Mea-
sure OD key to save the setting and proceed to the next kV cali-
bration point.
b. If not within range, press Measured OD field up or down adjust-
ment keys, to increase or decrease sensitivity value. (Note: this
adjustment will not be immediately seen in the image until after
all AEC KVP Calibration steps are performed.) DO NOT TAKE ANY
FURTHER EXPOSURES AT THIS SETTING.
22. Press the key next to the Measure OD field to save the first kV cali-
bration point entry (50 kV, 5 CM). The AEC KV Calibration screen is
updated for the next kV calibration point (60 kV, 10 CM).
BASE OPTICAL
DENSITY
SETTING
KVP MEASURE
SELECT FIELD
USE UP AND
DOWN
ARROW KEYS
TO ADJUST
TO CORRECT
VALUE
NOTE
Calibration of the
first step (50 kVp)
is not required as
long as AEC
Optical Density
Calibration
procedure in the
previous steps
was performed
prior to AEC KV
Calibration. A
verification that
the "Measured
OD" is the same
as the "Optical
Density" setting is
only necessary.
NOTE
Decreasing the
Measured OD
value below the
"Base Optical
Density setting"
will result in a
higher sensitivity
value reading of
the image.
Conversely,
increasing the
Measured OD
value above the
"Base Optical
Density setting"
will result in
lower sensitivity
value reading of
the image.
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