Cleaning The Beam Expander - Malvern Mastersizer Series Getting Started

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Caution!
Never remove the lens from the lens holder. The lens is precisely set at
manufacture.
Store the lens with lens caps on to avoid the need to repeat this procedure often.

Cleaning the beam expander

The beam expander will not require cleaning as often as the range lenses. Every
12 weeks however the lens should be carefully inspected for signs of dust. Always
remove the beam expander for cleaning.
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Caution!
Read the following instructions fully before starting to clean the beam
expander. Failure to follow the procedure correctly may result in the improper
functioning of the instrument.
To clean the lens the aperture plate must be removed. This plate is a beam stop
aperture that fits exactly around the emergent laser beam, helping to clean up
stray light. It is precisely located and will need to be re-fitted in the exactly the
same position on re-assembly.
A simple means to achieve this is to mark the orientation of the plate with a pencil
so that a line is drawn on the aperture plate and the beam expander body as shown
in the figure below À. Then loosen
Á. The front face of the lens may be cleaned by the same procedures used for the
range lenses.
C H A P T E R 1 1
one locking screw only
G E T T I N G S T A R T E D
to release the plate
P a g e 1 1 . 7