GE Brivo OEC 715, Service Manual

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Brivo OEC 715/785/865 Mobile C-Arm X-Ray Product Service Manual
3-46
3.6.4. Image Resolution
Place spatial resolution tool in the front of the image intensifier. The angle between the horizontal axis of
the image and the resolution tool must be 45
°
. Select appropriate kV value. Take an exposure and stop
once image is stable. The image is frozen on the left monitor. Verify the resolution in Lp/mm is equal to,
or greater than, the values listed below. Repeat and select any of three field sizes (NORM, MAG1 and
MAG2) to verify the resolution.
Field Size Model
MAG NORM MAG1 MAG2
Resolution (Lp/mm)
Brivo OEC 715/785 ≥ 2.0
≥ 2.6 ≥ 3.1
Brivo OEC 865 ≥ 2.2 ≥
3.0
≥
3.5
If the resolution check fails, refer to section 4.6.8 for Camera Focus calibration.
3.6.5. Dose Limitation Check
Normal Fluoro Dose rate check
1. Operate C-Arm to make the generator being top and the image intensifier being bottom.
2. Position the detector of dosimeter at the center of the X-ray beam 30cm above the grid of image
intensifier. Cover the image intensifier with lead plate thicker than 3mm.
3. Set KVp as 110kVp, increase mA to maximum in manual mode. Measure the dose rate while
making exposure. Limits vary by the dose group, which was configured in software configuration
section by country.
4. Refer to below table verify the corresponding Dose group according to country’s Dose group
requirement (refer to 5.2.4).
Continuous Fluoro:
≤
47.5 mGy/min (Dose group: Normal 50 and HLF 50)
≤
47.5 mGy/min (Dose group: Normal 50 and HLF 100)
≤
83.6 mGy/min (Dose group: Normal 88 and HLF 100)
HLF Dose rate check:
1. Position the dosimeter in the center of the X-ray beam 30cm above the grid. Cover the image
intensifier with lead thicker than 3mm for protection of the image intensifier.
2. Set kVp as 110kVp, increase mA to maximum in manual mode. Measure the dose rate while
making exposure. Limits vary by the dose group, which was selected in software configuration
section by country.
3. Refer to below table verify the corresponding Dose group according to country’s Dose group
requirement (refer to 5.2.4).
Continuous Fluoro:
≤
47.5 mGy/min (Dose group: Normal 50 and HLF 50)
≤
95 mGy/min (Dose group: Normal 50 and HLF 100)
≤
95 mGy/min (Dose group: Normal 88 and HLF 100)