Metrohm 833 IC Liquid Handling Unit - Manual (Page 98)

9 Troubleshooting - maintenance
830 IC Interface / Gebrauchsanweisung 8.830.1001
90
9.2.8 Ultrafiltration cell
The perfect condition of the filter membrane used is a necessary
requirement for the constant high quality of the analytical results, which
is why it must be replaced at regular intervals.
In order to asses the necessity of replacing the membrane please
consult Section 8.4.
To replace the filter membrane please proceed as follows (see also Fig.
22 in Section 8.2):
9.2.8.1 Replacing the filter membrane
1 Prepare ultrafiltration cell
• Loosen all capillary connections at ultrafiltration cell 66 by
unscrewing the PVDF compression fittings 64.
• Use the 6.2621.070 Allen key (5 mm) to completely loosen
the 5 screws 70, Separate upper part 67 from lower part 69
and remove sealing ring 72 and the used filter membrane.
2 Clean filtration cell, insert new filter membrane
and reassemble the cell
• See steps 2-6 Section 8.2 Assembling the ultrafiltration cell.
3 Connect filtration cell
• See steps 3-5 Section 8.3 Connect filtration cell.
4 Rinse ultrafiltration cell
• See also step 8 Section 8.3.
Each time that a new filtration membrane is inserted any air
that may still be contained in the filtration cell or tubing must
be removed. This is done by rinsing the cell and all the tubing
with e.g. ultrapure water:
• Immerse aspiration tubing 16 (see Fig. 24) in the rinsing
solution (degassed ultrapure water).
• Switch on the peristaltic pump in the «IC Net» software.
• Rinse the filtration system with ultrapure water for approx. 5
min. Check that the same amount of solution emerges from
both the waste outlets in the waste bottle.
• Check all tubing from the storage containers to the tubing
cassettes and filtration cell and up to the waste bottle for
leaks. If any leaks are found then the corresponding
connection must either be tightened up or replaced.
• If any air bubbles remain in the dialysis cell then screw off
PEEK capillary 80 (filtrate) from outlet 71 and the filtration cell
and wait until the air bubbles have vanished. Then screw the
tubing back onto the filtration cell again.