Only Trained Personnel should change Slitmasks

Changing a Slitmask

1. Login to honolii as lriseng.
2. Select 'Engineering | Changeout | All Reconfiguration Software' in the desktop menu. 
3. Juke the slitmask box using the Engineering GUIs available from the desktop menu.
4. Or click on the 'S' button next to the slitmask display box on XLRIS to get the Slitmask Selector pull down menu. Select the direct slitmask.
5. Only slitmasks may be changed in situ.á Remove LRIS to the Cass Platform as per procedures if you are also changing gratings and filters.á Rotate LRIS to the grating changeout position.á If LRIS is out of the telescope this is with the dewars at 12 oÆclock position (180—), or if in the telescope this is at 173¦.
6. Locate the masks that are being installed in LRIS.á Engineering masks are kept in the grey cabinet on the nas deck.á Custom masks are in the instrument lab.á See these instructions on how to locate custom slitmasks. Transport slitmasks in the case to avoid damaging them.
7. Unscrew the guide pin on the right side of the slitmask box then pull to remove.
8. Open the cover to the slimask juke box.
9. Rotate the retaining knobs adjacent to the position of the slitmask to be removed, remove the mask and stow in the slitmask case.
10. Remove the desired slitmask from the slitmask case, install in the empty position and rotate the retaining knobs to secure the slitmask. The arrow on the slitmask frame must point toward the secondary mirror.
11. Repeat the above two steps until all desired slitmasks are removed and installed.
12. Insert the guide pin and close the cover to the slitmask box.
13. Verify that the  4 amber LEDs on the bottom of the slitmask box are dark indicating that the cover has been fully closed and the guide pin has been inserted.
14. Return the slitmask box(es) to the appropriate place.