Metrohm 711 Liquino - Manual (Page 114)

4.8 SMPL mode - fully automatic sampling
711 Liquino, Instructions for use 108
PREP — preparation is important
All the Dosinos needed for the sampling mode must be prepared before the
start. In the SMPL mode the port occupancy of the sampling Dosino is
stipulated and does not correspond to the standard occupancy (see above
diagram).
When <PREP> is pressed in the SMPL mode, any defined auxiliary dosing
devices will be prepared first, i.e. the tubing and the dosing cylinder will be
rinsed with solvent. Then the actual sampling Dosino will be prepared in a
similar manner. In this case the PREP process also includes aspiration and
rinsing of the measuring cell.
External pumps
The use of two external pumps for aspiration and rinsing the measuring cell
simplifies the procedure and saves a considerable amount of time. Metrohm
Diaphragm Pumps 683 can be easily connected and are optimally support-
ed by the 711 Liquino.
Auxiliary dosing devices
Apart from the sampling Dosino (Dos1), three further Dosinos can be con-
nected to the 711 Liquino and used to add auxiliary solutions (e.g. buffer so-
lutions). This can occur during the sampling procedure directly before sam-
ple transfer or after diluting the sample in the measuring cell. After each
addition of an auxiliary solution a fixed waiting period can be programmed.
For time reactions this is absolutely necessary.
The port occupancy of the auxiliary dosing devices corresponds to the
standard settings (dosing port 1, filling port 2, waste port 4). For preparing
(PREP) the auxiliary dosing devices see above.
Titration and measuring instruments
Most Metrohm instruments can be used in combination with the 711 Liquino
as titration or measuring instruments. The following are particularly suitable:
titrators of the Titrino family and 726 Titroprocessor.
• Remote cable 6.2141.090 is needed to connect the Titrino; it is specially
designed for communication between Liquino and Titrino so that no
special settings are required on the instruments. If external Pumps 683
are used then multiple remote cable 6.2141.100 must be used; all the
necessary peripheral units can be connected with it.
The necessary remote lines are occupied as follows:
Liquino remote socket Peripheral unit Function
Input 3 (External Ready) - Titrino (Output 3) End of Determination EOD
Output 4 (Activate 1) - 683 aspiration pump Remote on/off
Output 5 (Activate 2) - 683 rinsing pump Remote on/off
Output 6 (External Start) - Titrino (Input 0) START
• If Titroprocessor 726 is connected a choice can be made between a re-
mote connection (with standard remote cable 6.2141.020) and a serial
RS232 connection (with serial cable 6.2125.110). With an RS232 connec-
tion the start command and the 'Ready' message can be freely selected.
In this case the Titroprocessor 726 takes over the role of the main con-
troller and starts the 711 Liquino.
In the process sequence of the Titroprocessor 726 the communication
commands must, however, be explicitly programmed.