Hologic Faxitron CT, Руководство пользователя

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FAXITRON CT USER MANUAL | HOLOGIC | REVISION 002
SECTION
Schedule of
Maintenance
8
8-8
Radiation Survey Procedure
1. Take a background radiation reading (point meter toward the center of the room) and
record the value (Note the units used on the Record / Form).
2. Complete an image calibration including a full system warm-up.
4. Open the chamber door and place the uniformity phantom on the CT pedestal.
5. In 3D mode press the “START” button and survey radiation emissions at the top, front,
back, and both sides of the cabinet. Slowly scan the entire surface with the meter. A 3D scan
takes several minutes but it can be repeated to give time to complete the survey.
6. Record the readings for each test location, except left side (the side with the detector).
7. If any readings are higher than the Faxitron radiation emission limit of 0.1 milli-Roentgen
(mR) per hour (1.0 µSv/h) at any point 5 centimeters (cm) outside the external surface (*),
contact a Faxitron or Hologic representative to discuss repair options.
(*) 0.5 mR/h at 5 cm from external surfaces is the upper limit by US FDA CDRH for
cabinet x-ray systems. If used in another country, please check with the hosting
country’s official limits for cabinet based in-vitro diagnostic radiography equipment.
For some countries, the test points should be at 10 cm from external surfaces and in
this case Faxitron radiation emission should read less than 0.1 mR/h at 10 cm from
external surfaces.
8. Remove the uniformity phantom from the x-ray chamber.
9. Repeat the survey for the left side of the system without the uniformity phantom. Verify
there is nothing in the x-ray chamber, start a 3D x-ray and scan the side of the system closest
to the detector.
10. Record which ever reading (with or without phantom) was higher for the left side.
8.9.0 Cont.