Metrohm 872 Extension Module Liquid handling - Manual (Page 15)

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3 Functioning
872 Extension Module – Liquid handling
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11 Central position
Connector connected with the transfer tub-
ing.
12 10-port valve
13 Selector
Can be rotated for selecting the active posi-
tion.
The selector can rotate in a clockwise or counterclockwise direction. Nor-
mally, the shortest path is selected when switching over to a new posi-
tion.
1
2
3
4
5
6
7
8
9
10
Secured positions
In order to avoid contaminations, any given position can be defined as
"secured". The secured position is moved to during switching only if it is
the goal of the switching procedure.
If the secured position lies along the shortest route during a valve switch-
over, then the longer path will automatically be selected.
Example: Switching from position 2 to position 5.
The shorter path travels via positions 3 and 4 (see illustration 4, left). If
however position 4 is defined as the secured position, then the 10-port
valve will automatically switch via the connectors 1 – 10 – 9 – 8 – 7 – 6
(see illustration 4, left).
X
1
2
3
4
5
6
7
8
9
10
1
2
3
4
5
6
7
8
9
10
Figure 4 Valve switchover, normal and with secured position