OEC 9800 Periodic Maintenance Procedure
48
Miscellaneous
Dose Area Product Calibration
The DAP Calibration procedure is performed by RUT software. In order for software to accurately calculate the Dose
Area Product (DAP) three coefficient values must be determined first. To determine the coefficient values you must
measure the dose rate in mR/s for 6 kVp settings (40, 50, 60, 80, 100, 120).
Calculate Coeffecients
1.
Remove the Workstation rear cover, exposing VGA and keyboard connector.
2.
Connect the cable from the external monitor to the VGA port on the Workstation's rear panel.
3.
Plug the external monitor's AC power plug into the nearest AC receptacle and turn on the power to the monitor.
4.
Connect the external keyboard to the keyboard connector on the Workstation's rear panel.
5.
Connect the RUT serial cable, open RUT, "connect" to the 9800 system and select the Dose Area Product
Calibration form.
6.
Place the Dosimeter in the center and on top of the II.
7.
Set the dosimeter to read the dose rate in R/s. All values should be entered in mR/s.
8.
Program the Dosimeter with the current temperature and barometric pressure (some dosimeters have temperature
and barometric pressure sensors built in).
9.
Select Manual Fluoro mode.
10. Open the collimator iris and leaves completely. You should not be able to see the iris or leaves when you take the
exposure. Press the x key on the external keyboard and verify on the external monitor that the iris position is 0
(+1/-10)% closed and the leaves are 0 (+1/-10)% closed.
Note
:
Pressing the x key acts as a toggle switch and enables and disables the DAP.
