LORAD AFFINITY Series, Руководство по обслуживанию

Страница: 66 / 214

4-10 P/N 9-500-0255
Service Manual
Chapter 4: Calibrations and Performance Checks
Exposure System Calibration
14. Set the unit for a Manual mode exposure at 39 kV, 80 mAs, Rh filter. Monitor the voltme-
ter from behind the radiation shield, then conduct the exposure.
15. The voltage reading on the voltmeter for 39 kV should be 3.9 VDC (±0.078 VDC using
10,000:1 voltage divider), or 39 VDC (±0.78 VDC using 1,000:1 voltage divider).
16. If the voltage reading is not within the specification above, readjust R41 on the HV Con-
trol Filament Board.
Legend for Figure 4-3
1. Coaxial Cable
2. Digital Multi Meter
3. Anode
4. BNC to Banana Plug Splitter
5. Ground side of splitter (Side of splitter with “Tab” must be connected to Common.)
6. High Voltage Divider
7. Cathode
8. Ground wire (Attach this end of ground wire to unpainted metal surface on Gantry.)
9. Gantry
10. HV Adapter Cable
11. Voltage Divider Receptacle
12. HV Test Well
13. mA Current Jack (not shown, on left side of HV Multiplier)
Figure 4-3: High Voltage Generator Calibration Setup
17. Repeat the exposure and check the voltage reading. Repeat Steps 14, 15, and 16 until
the voltage reading at 39 kV is within the ±2% specification.
18. Check the voltage at 20 kV to verify that it remained within the ±2% specification. If
necessary continue to make adjustments at 20 kV, then at 39 kV until calibration at both
levels is achieved.