When remounting, the screws should again be re-tightend carefully
to avoid one-sided pressure on the o-ring/window
Be careful as the window is quite heavy! KRS5 is three times more
heavy than glass, so the window is about as heavy as if it were made
of steel!
KRS5 is not particulary brittle, but a bit soft
It takes 2 people to unmount.
The safe way to unmount is to unscrew the securing ring on the outside,
by unscrewing slowly and evenly. Please do not just take out one screw
after the other, but release them sequentially in the beginning by
quarter turns only.
When the screws are loose you take off the ring (including the O-ring).
Now one person with gloves and lens-cleaning tissue prepares to accept
the window when it comes loose.
The other person gently over-pressurizes the vessel until the window
moves.
Now the window can be removed with a piece of card-board or equivalent
by carefully working on the circumference. But watch out, the window
is very heavy and I would also recommend to put some foam rubber on
the table, "just in case".
When you remount make sure that the window does not get reversed,
what is the outside should stay the outside. The reason is, the window
has a couple of scratches on both sides and at least the way it is
now is the best.
When re-assembling you have to inspect the circumference for the scratches
and put some vacuum grease at the scratches where the o-ring will
be. Otherwise you will have a leak!
I would also recommend after re-assembly to measure the zero-point
of polarisation
