Metrohm 800 Dosino - Manual (Page 27)

￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭ 4 Functioning
800 Dosino ￭￭￭￭￭￭￭￭ 19
The dosing drive sitting on the dosing unit turns, with the rotating drive
pin, the centering tube and thus the entire interior cylinder unit, with dos-
ing cylinder, cylinder base and the valve disc mounted within.
The bore hole of the valve disc faces a different distributor disc opening
after one rotation of the cylinder unit. This means that a different port is
selected for dosing (or filling).
4.3 Port assignments
The distributor of a dosing unit has four inputs/outputs (ports), which can
be freely selected. An additional connection, the VENT -Port (see Figure
12, page 19), leads directly to the underside of the distributor and can-
not be actuated by the valve disc. It deaerates the supply bottle and can
be equipped with an adsorber tube.
Port 1
Port 2
Port 3
Port 4
Vent
Figure 12 807 Dosing Unit from below
All ports of the 807 Dosing Unit can be used differently (see Chapter 4.4,
page 20). This is an important precondition for complex liquid handling
tasks. Titrandos use a standard port allocation which is the most suitable
for titration tasks.