Metrohm 846 Driver Toolbox - Manual (Page 12)

1.3 Metrohm 700/800 Dosinos and Dosing Units
8 Dosing Interface USB Toolbox, Overview
1.3.4 Standard occupancy of the Dosino ports:
Port 1 Dosing outlet; M6 threaded connection on the left-hand side of
the housing.
The liquid is ejected through a dosing tip or a titration tip.
Port 2 Filling inlet; M6 threaded connection on the base of the dosing
unit.
The liquid is aspirated from a storage container.
Port 3 Not assigned; M6 threaded connection on the right-hand side of
the housing.
Port 4 Special functions; narrow connection nipple on the base of the
dosing unit. This can be used during the 'PREP' function for
ejecting the liquid. When the dosing unit is emptied port 4 is used
as the air inlet.
VENT Vents the storage container; M6 threaded connection at the front.
A drying tube can be connected to it, e.g. filled with molecular
sieve or soda lime.