30 Simple
Maintenance
4. Push out the light guide and strip the PTFE sealing ring in order to
clean the lens.
5. Reassemble the cell in reverse order. Use a new PTFE sealing ring
after every disassembly to ensure the consistence of the flow cell.
Adjusting the path length of the preparative flow cells
SOP 8
Changing the path length
This instruction applies to flow cells A4066, A4067 and A4068 with 1/8”
and 1/4” connectors. Path lengths can be adjusted to 2, 1.25 and 0.5
mm. On delivery the path length is set to 2 mm. To reduce the path
length to 1.25 or 0.5 mm, follow the instructions given.
1. Unscrew the outer thread with the 3 mm hexagonal spanner.
2. Take out the stainless steel plain washer and the PEEK distance
plate.
3. Remove the distance plate, put back the stainless steel washer
and refasten the thread carefully.
With the distance plate removed, the rod shaped light guide is pushed
further into the flow cell (0.75 mm), thus resulting in a reduced path
length of 1.25 mm. To reduce the path length further to 0.5 mm, follow
the same procedure on the other side of the cell.
To extend the path length again in steps of 0.75 mm, the PEEK
distance plates have to be inserted again.
4. Loosen the outer thread, remove the stainless steel plain
washers and take out the gasket holder by using a pair of
tweezers.
5. Push the light guide approximately 1 mm to the outside to
enlarge the path length. Use a clean cloth and do not touch the
light guide with the fingers.
6. Put the gasket holder back into the cell.
7. Insert the PEEK distance plate again and then the plain washer.
8. Fasten the outer thread carefully.
When fastening the threads, the rod shaped light guide is pushed back
in the correct position inside the cell. Inserting a distance plate thus
enlarges the path length for 0.75 mm. It is not necessary to change the
PTFE sealing ring when adjusting the path length.
Flow cells with fiber optical connectors
Changing the path length of flow cells with fiber optical connectors can
be done in the same way. In these cells the screwthread is replaced by
a special adapter (Fig. 29). They additionally contain a lens to focus the
light onto the optical fibers.
Fiber optical connector with lensholder
Lens
PEEK shutter
PEEK distance plate
Gasket holder
Light guide with PTFE seal
Fig. 29
Fiber optical connector of a preparative flow cell
Summary of Contents for WellChrom K-2600
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