Tools Required:

• Allen wrenches
• Palm grip handle tool found in the LRIS storage area on the Keck 1 Nasmyth deck

Procedure

The following procedure applies to the removal of the blue dichroics on LRIS.

1. Log in as lriseng and bring up a punaluu xterm window. Type the following command at the punaluu prompt:
   • s dichtran (should read dichtran=stowed; if not type m dichtran=0 to move the dichroic into the carousel)
   • dichload.tcl (This will bring up a small GUI window which allows you to rotate the appropriate carousel.)
2. Click on the position number you wish to remove, and click the SET button to move the carousel. The carousel is now in position for replacing the dichroic.
3. Rotate LRIS so that the dichroic carousel is at the top of the instrument. This will make it much easier to load and unload the dichroic.
4. Climb on top of the instrument and locate the carousel.
5. Pull the tethered T-handle which locks the load door in place. Note: The pin is an interlock for the carousel!
6. Open the load door.
7. Screw in the palm-grip handle. This allows you to lift out the filter, and also locks down the latching mechanism to the cell assembly.
8. The holder is kept in place using 3 or 4 screws which secure the optic cell around the edge of the plate. Use a 7/64 hex wrench to loosen these captive screws until they rattle.
9. Carefully lift the dichroic out of the carousel.
10. Place the dichroic to be serviced in its storage case or cart.
11. Remove the palm-grip handle from the element.
12. If removing more than one dichroic, repeat steps 9 thru 13.
13. Close the load door.
14. Insert the tethered T-handle which locks the load door in place.