Metrohm 792 Basic IC - Manual (Page 164)

5.2 Maintenance and servicing
792 Basic IC
155
5.2.10 Exchanging the pump tubing
The pump tubings used by the peristaltic pump are consumable mate-
rial with a limited lifetime and should be exchanged at regular intervals
(approx. every 4 weeks under continuous use).
The working life of pump tubing depends to a considerable extent on
the contact pressure. This is why the contact pressure must be correctly
set as described in section 2.9.2. If the pump is to remain switched off
for a lengthy period of time the tubing cartridges 40 40 40 40 should be raised
completely by loosening the snap-action lever 43 43 43 43 on the right-hand side
(the set contact pressure remains unchanged).
As the pump is always operated on the same side, the 6.1826.060
Pump tubings supplied can be used on both sides. To exchange a
pump tubing proceed as follows:
1 Remove old pump tubing
x Press contact pressure lever 41
41 41 41 on the tubing cartridge 40 40 40 40
down as far as it will go.
x Release tubing cartridge 40
40 40 40 from holding clamp 42 42 42 42 by press-
ing down snap-action lever 43 43 43 43 and remove from mounting pin
45 45 45 45 (see Fig. 14).
x Remove old pump tubing 71
71 71 71 or 72 72 72 72.
2 Insert new pump tubing
x Insert the new pump tubing 71
71 71 71 or 72 72 72 72 in the tubing cartridge
40 40 40 40 as shown in Fig. 13. The white-yellow stopper 73 73 73 73 must
click into the corresponding holder on the left-hand side of
the tubing cartridge.
x Place the tubing cartridge 40
40 40 40 on mounting pin 45 45 45 45 and press
down on the right-hand side until snap-action lever 43 43 43 43 clicks
into position on holding clamp 42 42 42 42. Take care that no kinks are
formed in the pump tubing.
3 Set contact pressure
x Switch on peristaltic pump.
x Press contact pressure lever 41
41 41 41 upwards until the solution
just starts to be drawn in. Then press contact pressure lever
upwards until it clicks once more to obtain optimal contact
pressure.
x Switch off peristaltic pump.