Metrohm 730 Sample Changer - Manuel (Page 110)

4.5 Sample Racks
730 Sample Changer, Detailed Description 107
The Shift position determines the correct position of the titration
head (Lift), in which the rack can be turned. If the lift is not at or
above the shift position, the sample rack can not be turned in
manual operation. This is a safety feature to prevent damage to
electrodes due to turning maneuvers of the rack. However, a pre-
requisite is that this shift position is correctly set. In a process se-
quence the positioning of the lift to the shift position can be pro-
grammed with 'LIFT:1 : shift mm'.
The following racks are predefined (standard settings):
The Special position determines an additional user defined
height of the titration head (Lift). E.g. for pipetting with the swing
head it can be chosen in a way that the pipetting tip just dips into
the sample solution. This special position can be accessed with
'LIFT:1 : special mm'.
Special beakers
Special beakers are reserved positions in a sample rack. 0 to 8
special beakers can be defined per rack. They can be placed un-
der a lift during method processing for particular operations with-
out interrupting or hindering the sample series run. Special beak-
ers can be used in a sample sequence for rinsing the electrode or
in a start sequence for calibrating an electrode (buffer solutions).
Special beakers are placed under lift 1 with 'MOVE 1 : spec.1'.
Reserved special beaker positions, that can be individually defined
for each rack, are recognized as such in a sample series and are
omitted during processing of the individual sample beakers.
If a special beaker is required in a method process but the sample
changer finds no beaker present in the reserved position, an error
message will always be displayed.