Requirements:

• Rotator needs to be at stationary 90 degrees.
• Contact instrument specialist and verify that no one will be testing LRIS.
• The new filter should already be mounted onto the modified filter frame.
• Non/latex gloves and face mask is required when working around
optics.

Objective:

Procedure:

1. Verify that there are no grisms in the deploy position. Use keyword s gtran on a punaluu xterm to verify this. If grism in deploy position, m gtran=0 to stow.
2. Move grism carousel to either load position #4 or position #6 using keyword command m grisload=# (where # is the position of the new assembly).
3. Open the grism hatch to remove the dummy cell. By removing the hatch pin an interlock is set, disabling any grism functions.
4. Screw the cell handle tool into the center of the retention plate assembly.
5. Using a 7/64 allen wrench, loosen 4 captive socket head cap screws.
6. Remove dummy cell from carousel.

Installing a new filter to an existing grism dummy cell: The filter has one side that is more silver than the other, and it is recommended that the silvered side faces the incoming light.

1. Remove the retention plate assembly by manually releasing the latch from the retention groove.
2. Remove the bolt that holds the weight onto the cell.
3. Remove the two brackets that are only used for future grisms, and set them aside.
4. Carefully slide the modified filter frame into the grism cell and secure with 4 6-32 socket head cap screws. Two in the front and two in the back.
5. Install the aluminum bushing on the bottom of the cell and secure with an 8-32 socket head cap screw.
6. Verify that all the new socket head cap screws are secured.
7. Install the retention plate assembly.
8. Screw the cell handle onto the retention plate assembly

CAUTION SHOULD BE TAKEN WHEN INSTALLING THE NEW FILTER IN THE GRISM CAROUSEL.

1. Carefully install the new cell into the open slot of the grism carousel. This should already be in position.
2. After the new cell is in the carousel, secure the 4 socket head cap screws with the 7/64 allen wrench.
3. Remove the cell handle.
4. Close hatch and install interlock pin.

Test and Update:

1. Rotate carousel and verify that the new assembly clears the latching mechanism plunger.
2. Deploy and stow the new assembly. Use keyword m griscar=# (where # is the position of the new assembly). Use keywords m gtran=1 to deploy and m grtan=0 to stow.
3. Update the software to reflect the change.