LORAD AFFINITY Series, Руководство по обслуживанию

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P/N 9-500-0255 4-41
Service Manual
Chapter 4: Calibrations and Performance Checks
Performance Checks
2. Set the unit for an Auto-Time exposure at 28 kV, Large focal spot. Set the Density com-
pensation to +5, and select the film type being used.
3. Make an exposure and verify that the post-exposure mAs value is less than 5 mAs and
the message “ERROR 21: EXP TIME” appears. (For complete alert code definition, refer
to Chapter 5, Table 5-2.)
4. Verify that the unit displays a caution that informs the user that the calculated exposure
has exceeded the maximum. Try to make another exposure before resetting the unit and
verify that x-ray generation is prevented.
5. Clear the message by pressing Reset . Repeat the test at 35 kV, Small focal spot, and verify
the same caution appears in the message area.
6.8 System Level Functional Check
This check verifies system functionality.
1. Apply power to the system. Verify the display works, and power is applied to Gantry.
Check control panel display for alert messages.
2. Set unit for a short exposure (25 kV, 3 mAs, Manual Mode, Large Focal Spot). Take expo-
sure.
3. If no problems found with exposure, return unit to operations.
6.9 Optical Density (Users Preference) Verification
This procedure verifies that the system falls within the users preference for optical density.
1. Remove any meter, scope, or probe from the machine that was used in any procedures
prior to beginning this verification.
2. Install the Bucky with a loaded cassette, on the IRSD.
3. Place the ACR Phantom on the IRSD, centered laterally, and positioned 1.0 cm back
from the chest wall edge.
4. Move the AEC Detectors so that they are directly under the ACR Phantom.
5. Set the unit for an exposure using the default exposure mode. Make an exposure.
6. Remove the cassette and develop the film.
7. Check the film’s optical density and verify that it is at the mean optical density as
required by the site.
8. If the optical density of the film is not within site required limits, perform the AEC Cali-
bration procedures as per Chapter 4, Section 5.0, Automatic Exposure Control System
Calibration.
6.10 IRSD Leakage Check
This check is performed at the factory and is not required at installation. However, it will be
necessary to perform this check after repairing or replacing the IRSD.
1. Connect a radiation scatter probe (100 square cm) to the readout/logic module of a radi-
ation rate meter. Set the meter’s operating mode to read in exposure in milliroentgens.
Place the readout/logic module so that it can be viewed from behind the radiation
shield.