Metrohm 872 Extension Module Liquid handling - Manual (Page 48)

7.3 Peristaltic pump
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872 Extension Module – Liquid handling
CAUTION
The 6.1826.xxx pump tubings consist of PVC or PP and therefore must
not be used for rinsing with solutions containing acetone. In this case,
use other pump tubings or use another pump for rinsing.
7.3.2 Maintenance
7.3.2.1 Pump tubing
The pump tubing used in the peristaltic pump is a consumable whose ser-
vice life is restricted.
The LFL pump tubing with 3 stoppers is stretched in the tubing cartridge
in such a way that it comes to rest between two stoppers. This results in
two possible positions for the tubing cartridge. If the pump tubing should
exhibit clear signs of wear, then this can be stretched a second time, in
the respective alternate position.
Therefore replace the pump tubing periodically, or when used perma-
nently approx. every 4 weeks .
Selecting the pump tubing
The pump tubing differs in material, diameter and hence also pumping
capacity. Depending on the application, different pump tubings are used.
The following table provides information on the properties and use of the
pump tubing:
Table 2 Pump tubing
Order
number Name Material Inner
diameter Use
6.1826.020 Pump tubing (blue/
blue), 2-stopper PVC (Tygon
ST) 1.65 mm Pump tubing for online IC
instruments and automa-
tion in voltammetry
6.1826.310 Pump tubing LFL
(orange/green), 3-
stopper PVC (Tygon) 0.38 mm Pump tubing for bromate
determination using the
triiodide method.
6.1826.320 Pump tubing LFL
(orange/yellow), 3-
stopper PVC (Tygon) 0.48 mm For suppressor solutions,
acceptor solutions for
inline dialysis and for inline
ultrafiltration.