STEP E8: Table/Gantry Alignment

note:

This procedure is designed to verify final table/gantry alignment with X-ray.

Prerequisites: Table Height Characterization is complete and the table is level head-to-foot and side-to-side.
Drive the table to its highest elevation.
Drive the table cradle in and out five times to seat the rollers.
Tape a 100 mm section of tungsten wire on the cradle that aligns with the white cradle centerline.
Turn on the alignment lights. Using the gantry keypad, set an internal landmark, and then advance the cradle 1000 mm.
Tape second 100 mm section of tungsten wire on the cradle that aligns with the alignment light.
Setup a scan to take a simple image of the wires at both locations. (Alternatively, this can be done by running the PERPENDICULAR ALIGNMENT protocol.
Compare the two images in IMAGE WORKS. Both wires must be within ± 2 mm of center.
If not centered within specification, loosen the anchors and move the table. The adjustment is likely to require a very small movement. Use a suitable tool to move the table the required distance.
Rescan to confirm each movement trial. This can take a few trials to move the table to a position that is within the specification.
Repeat above steps until both images are visually aligned on the screen.
Verify that the table is still level. Use a calibrated torque wrench to tighten the anchors to 75 ± 6 N-m (55 ± 5 ft-lb).