Quantum ODYSSEY HF Series

Appendix D Calibration (Using Generator Service Tools)
HF Series X-ray Generators - Service Manual Revision W
Quantum Medical Imaging, LLC D-57
9. If not within range, press Repeat button and perform the following
adjustments:
a. Adjust Table Gain Adj. potentiometer (if calibrating the table recep-
tor) or Wall Gain Adj. potentiometer (if calibrating the wall receptor),
and re-take exposure. Continue until the measured density value
equals the Target Level setting to within DR System manufacturer’s
specification.
b. If you still cannot achieve the Target Level setting, set Table Gain Adj.
potentiometer (if calibrating the table receptor) or Wall Gain Adj.
potentiometer (if calibrating the wall receptor) to mid-range, then
adjust the ion chamber’s MASTER GAIN potentiometer until roughly
the desired density is obtained. Further fine-tuning can then be
achieved by adjusting the Table or Wall Gain Adj. potentiometer as
described in the previous step.
c. If the measured density value still does not equal the Target Level
setting even with the ion chamber’s MASTER GAIN potentiometer set
to maximum gain position, increase gain of each chamber detector
and perform the "AEC MAS Balance Verification" procedure. Repeat
Base OD calibration.
d. If the measured density value still does not equal the Target Level
setting after adjusting the MASTER GAIN and gain of individual
detectors, reduce the Offset value until the desired density value is
obtained.
If the selected Receptor/Film Screen is not the first one to be calibrated with
the system, perform the following steps:
1. Set the "Target Level" to the desired level (e.g., "650.00" as shown in Fig-
ure D-31). To do so, set the OD range (located directly below "Optical
Density" field) for 10-1000. Enter the Optical Density value by adjusting
the slide control, or by selecting the data entry box and typing the value
using a keyboard. The value entered should be to the hundreths decimal
place.
Do not change the Target Level setting at any time during this
procedure.
2. Place 5 CM of acrylic in the X-ray beam completely covering the ion
chamber detectors.
3. Take an exposure at the setting indicated on the Base OD Calibration
Screen (i.e., 50 kVp, 200L mA, normal density).
4. On film systems, develop the film and then measure its optical density.
On CR or DR systems, observe the density level displayed on the inte-
grated system’s workstation computer.
5. If the density value is within acceptable range of the Target Level (on CR
or DR systems, refer to manufacturer’s specifications), press the Cali-
brate button to save the setting and proceed to AEC kVp Calibration.