Del Medical EPEX Omniflex IV, Руководство по обслуживанию

Страница: 130 / 238

EPEX/Omniflex IV System Service Manual
4-46 Adjustments and Calibration
AEC kVp Compensation for Film Screen 2
To determine the AEC kVp compensation for Film Screen 2:
Step Action
1 Connect the Service Laptop to the Generator.
2 From the GenWare Utility AEC Calibration Points menu screen,
choose Film screen 2 .
3 Adjust the reference volts as shown in the form below.
4 Acquire exposures using the following techniques:
50 mA
250 ms backup time
AEC cell #2
Film screen 2
Grid Speed 2
40 in. HSID or VSID
Collimator in auto mode, 25 x 25 cm field size
Grid in.
5 Use DRIVEL to acquire a DV (Mean) for image center as the ROI.
6 Ensure all DV (Mean) measured is within 200 of each other and
respective to 65 kVp data point in the table.
7 Record the AEC mS, DV (Mean), and the DV (Mean) delta in the
AEC kVp Compensation for Film Screen 2 form found in
Appendix C. A sample is shown following this procedure.
8 Repeat steps 3 to 7 for each kVp listed on the form.
9 This is an iterative process to adjust the kVp to the reference level to
bring the multiple high(s) and low(s) DV (Mean) closer to the
DV (Mean) data point at 65 kVp. Do not re-adjust the 65 kVp
reference volts. The final exposure should have a Delta < 200 to the
acquired DV (Mean) at 65 kVp.
10 Repeat this procedure as an iteration. Record only the adjusted
reference and the resulting AEC ms, DV (Mean), DV (Mean) delta
in the AEC kVp Compensation for Film Screen 2 iteration forms in
Appendix C. A sample is shown following this procedure.
Note: Write N/A or – for the non adjusted data.