Preparative Flow Cells; Adjusting The Path Length Of Preparative Flow Cells; Sop 12 Cleaning A Preparative Flow Cell; Sop 13 Changing The Path Length - Knauer Smartlibe UV Detector 2500 Handbuch

32

Preparative flow cells

Fig. 32
SOP 12

Adjusting the path length of preparative flow cells

SOP 13
Stainless steel
shutter
Gasket holder
Sectional view of a preparative flow cell
Cleaning a preparative flow cell.
This instruction applies to the preparative flow cells A4066, A4067,
A4068, A4069, and A4095.
The preparative flow cells have a rod shaped light guide instead of the
concave lens in the analytical cells.
1. Unscrew the outer thread with a hexagonal spanner
2. Take out the stainless steel shutter and the PEEK distance plate (not
present in A4069, A4095).
3. Get hold of the gasket holder with the light guide by grasping it with a
pair of tweezers, using the indentations on the outer side of the gasket
holder.
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.
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 shutter and the PEEK distance plate.
3. Remove the distance plate, put back the stainless steel shutter 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.
1. Loosen the outer thread, remove the stainless steel shutter and take
out the gasket holder by using a pair of tweezers.
2. 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.
3. Put the gasket holder back into the cell.
Simple Maintenance
Screw thread
PEEK distance plate
Light guide with
PTFE seal