These tests should only be done by designated personnel (i.e. Facility Manager) while there is no user in the X-ray room - surveys indicate there are no X-rays scattering past the enclosure but distractions are to be avoided. The tests must be done at least once every six months and entered into the log book. They cannot and must not be done while data collection is ongoing.
Test the X-ray & Shutter Indicator lamps
There are three large lamps of relevance:
- Large amber "X-ray On" lamp that is lit whenever the generator makes X-rays (table top)
- Large red "shutter open" lamp for RIGHT port - is lit whenever shutter is open (table top)
- Small red lamp for RIGHT shutter - is lit whenever shutter is open (top of shutter housing)
- Larger red "shutter open" lamp for LEFT port - this should never be active, shutter will not open
- Small red lamp for LEFT shutter - shutter should never be open, so should not light
Make sure the backstop is installed and nobody is inside the enclosure. Make sure the metal cover is on the detector. You do not need to be inside the enclosure to run these tests.
Exit the enclosure and close the enclosure door to enable the interlock. Reduce the X-ray power to 20 Kv and 10 mA to reduce scatter.
Test the normal operation of the X-ray & Shutter lamps
Verify that the amber X-ray on lamp is lit when the X-rays are being generated.With the X-rays on, use the XGControl software to open the right shutter - you should see that the large red table top light goes on, and the smaller red light on top of the shutter housing goes on. Close the shutter. Try and open the left shutter - this should not open and neither shutter indicator lamp should go on.
Enter the enclosure with the shutter closed. Remove the central screw and separate the LED assembly from the table-top right shutter lamp. The X-rays should cut out immediately and an audible alarm will be generated. Reassemble the lamp. To reset alarms, go into XGControl>Condition and Reset Alarm (reads Alarm 0/AX3116). Restart X-rays. Exit the enclosure, close door and check that the lamps now light when XGControl opens the right shutter.
Using the same procedure as the shutter bulb, disassemble the X-ray ON amber lamp and confirm that X-ray generation ceases. An alarm will sound. Reassemble the lamp and reset the alarm in XGControl>Condition(shows Alarm 0/AX2114). Start X-rays again and make sure that map is lit.
This is an active test of fail-during-operation scenarios. The LED bulbs should be long-lived.
Testing the Enclosure Interlock
Close the door of the enclosure. With the X-rays on and yourself outside the enclosure, use XGControl to open the shutter and Verify that the two red shutter open indicator lights are lit. Open the enclosure door and be certain that the shutter closes.Close the door again, and re-check the shutter lamps. Open the door and Verify that the shutter will not open while the enclosure door is open. . Close that door and unlock and open the second (left-most) enclosure door. Verify that the shutter will not open while either enclosure door is open. .
Testing the Enclosure Interlock Override
For this you need the override keys, and if you don't know where the override keys are you shouldn't be doing the test....only the Facility Manager should ever do these tests.With no-one else in the room: for each machine, enable the override with the override keys, open an enclosure door, open the shutter using the XGControl software. Close the shutter and re-arm the interlock and remove the keys.
Note that the override keys are of questionable relevance even for maintenance since you can do everything else without ever needing to be in the enclosure, by using the XGControl software.
Leave the system in the non-overriden state that is safe for general use: keys removed from the enclosure override and the shutter override (not used during this procedure) and both left in the disabled state.