- 3/32 allen wrench
- Palm grip handle tool found in the LRIS storage area on
the Keck 1 Nasmyth deck or in the instrument lab LRIS
cabinet (bin marked special tools).
- hairnet or cap
The following procedure applies to the removal of the blue filters
from grisms cells.
- Locate new filter and old filter storage boxes. These are
located on the bottom shelf of the cabinet located next to
the laminar flow bench.
- If you need to remove the grism cell from the instrument
first please follow the instructions Remove Grism
- Insert palm handle into grism cell top plate if not
- Place the Grism cell in the laminar flow bench with the
retaining baffle face up as seen in the picture below.
- Remove the four socket head screws securing the square
- Remove the square filter retainer. .
- Remove the filter and the delrin frame from the grism
cell. You may have to use a small screw driver to lift from
the filter frame from the corners. You also may have to wait
until the cell is at room temperature.
- Pack filter in appropriate storage box.
- Unpack new filter which should be already installed in a
- Install filter+frame into the grism cell. It is a tight
fit so you have to drop it in almost vertical. The local
lore is shiny side up, but it should not matter.
- Install and secure the square retainer.
- Re-install in instrument if necessary. See Remove Grism