Metrohm 711 Liquino - Manual (Page 113)

4. Detailed description
711 Liquino, Instructions for use 107
• Start determination: a start signal is transferred to an externally connect-
ed instrument via the remote interface (or RS232). The actual determina-
tion is started.
• Wait for end of determination: the Liquino waits until a completion signal
is received from the external instrument via the remote interface (or
RS232) to indicate that the determination is finished. The next sample
can then be processed similarly.
For series of samples or multiple determinations on the same sample the
number of times that the sampling cycle is to be repeated can be preset. In
this way several samples can be taken and determined automatically. A de-
lay period of any length can be inserted between the individual cycles.
It is possible to further automate the sampling procedure by using a
Metrohm 730 Sample Changer.
The sampling Dosino
1
4
2
3
Port 4
Waste
Port 1
Sampl Solvent
Port 3
Measuring
cell
Port 2
Dosing
cylinder
4-way
stopcock
A Dosino 700 with a dosing unit (with 5, 10, 20 or 50 mL
cylinder), which must be connected to the Dos1 socket of
the Liquino, is used for transferring the sample to the
measuring cell. In addition, it can also add solvent and can
aspirate the measuring cell and rinse it if no external
pumps are used.
In order to prevent carryover of sample solutions and to
ensure as high a degree of accuracy and correctness of
the determination results as possible, complex rinsing
processes are incorporated in the SMPL mode.
In all dosing and aspiration processes carried out by a
Dosino the corresponding tubing volumes are taken into
account. It is therefore absolutely necessary that the defini-
tions of the dosing units (tubing diameter and lengths, see
page 68) are carried out properly and accurately and that
in the parametrization of the SMPL mode the correct dos-
ing unit is entered under 'Parameter >SMPL Dosing units'.
See also pages 22 and 68.
Port allocation of the sampling Dosino:
Port: Function:
1 Aspirate sample
2 Fill or aspirate
measuring cell
3 Aspirate solvent
4 Discharge waste