Metrohm 838 Advanced Sample Processor

2.8 Dosing and liquid handling
Metrohm 838 Advanced Sample Processor, Operation 55
The Dosing unit has four ports (inlets/outlets) to which various functions
can be assigned. There is an additional outlet (VENT or 0) that is used
for venting the bottle on which the Dosing unit is mounted.
Fig. 7 Dosing unit from below
VENT/0 – is used for venting the storage bottle and is normally fitted with an ab-
sorber tube (filled with a drying agent).
Port 1 – is side-mounted and is defined as dosing outlet 1 as standard.
Port 2 – is located on the base and is defined as the filling inlet as standard; it is
normally fitted with a standpipe.
Port 3 – is side-mounted and is defined as dosing outlet 2 as standard.
Port 4 – is located on the base and is defined as the air inlet opening for empty-
ing the tubing system as standard.
The maximum dosing and filling rates, which can be entered for each
port of the Dosing unit in the configuration menu under
>Dosing units,
depend on the cylinder size:
Cylinder volume Max. dosing rate Resolution
2 mL 6.6 mL/min 0.2 µL
5 mL 16.6 mL/min 0.5 µL
10 mL 33.3 mL/min 1.0 µL
20 mL 66.6 mL/min 2.0 µL
50 mL 160 mL/min 5.0 µL
VENT/0
Port 3
Port 2
Port 1
Port 4