Metrohm 711 Liquino - Manual (Page 112)

4.8 SMPL mode - fully automatic sampling
711 Liquino, Instructions for use 106
4.8 SMPL mode - fully automatic sampling
The SMPL mode (sampling) of the 711 Liquino is used for automated sam-
pling and transfer of the sample to a measuring or titration cell.
Sample
Solvent
Waste
Measuring
cell
Auxiliary
dosing drive
The Liquino with SMPL mode represents a sensible
addition to all titrating instruments (e.g. the Metrohm
Titrino family). It makes automatic functions availa-
ble which are otherwise reserved for sample chang-
ers or computer-controlled analytical systems.
The 711 Liquino does not just carry out sampling,
i.e. the aspiration of the sample, but also controls
the addition of solvent and auxiliary solutions, rins-
ing the measuring cell (also with the help of external
pumps) and the synchronization of the measuring
or titration instrument.
In on-line analysis sampling can take place at de-
fined time intervals and automated analyses can be
carried out.
SMPL mode procedure
The various phases of automatic sampling can be divided as follows:
• Aspirate measuring cell: the measuring cell is first emptied and its con-
tents transferred to the waste bottle. This process can be carried out with
the help of an external pump or by the sampling Dosino.
• Rinse measuring cell: measuring cell, tubing and the dosing cylinder of
the Dosino 700 are rinsed with solvent. Excess solvent is discharged to
the waste bottle. The measuring cell can be aspirated with an external
suction pump if required.
• Rinse dosing cylinder: the dosing cylinder of the Dosino 700 is rinsed
with sample solution. Excess sample solution is discharged to the waste
bottle.
• Add auxiliary solutions: auxiliary solutions can be added by further
Dosinos.
• Transfer sample: the sample is aspirated into the dosing cylinder and
dosed into the measuring cell.
• Rinse dosing cylinder: the dosing cylinder of the Dosino 700 is rinsed
with solvent. Excess solvent is discharged to the waste bottle.
• Dilute sample: solvent is aspirated and dosed into the measuring cell.
• Add auxiliary solutions: auxiliary solutions can be added by further
Dosinos.