Metrohm 774 Oven Sample Processor - Manual (Page 96)

5 Detailed description
774 Oven Sample Processor, Instructions for use 90
The following recognition data can be defined for each rack:
Rack number
unique identification
Code automatic rack recognition
Type racktype / position table
Work position working height of the lift head
Rinse position rinsing height of the lift head
Shift position turning height of the lift head
Special position freely available lift position
Special beaker position reserved beaker positions
(spec.1 to 8)
The Rack number serves to identify a rack. It can be chosen from 1 to 16.
In a method a particular rack number can be assigned to the process se-
quences (see page 70). This ensures that if the wrong sample rack is
used, the automatic rack recognition will realize this and issue a warning to
the user.
The Code is used for automatic rack recognition. Make sure that this 6-
place binary code in the rack configuration agrees with the actual inserted
magnet code on the rack. Rack codes can be changed at any time. They
must however, only be assigned to one rack. The assignment of standard
predefined codes of racks provided by Metrohm should be avoided.
The rack Type serves for the assignment to a position table internal to the
instrument, in which the positions of the sample beakers in the rack are de-
fined in tenths of a degree (0-3599) of the full turning angle. The rack type
is coded as Mxx-y, whereby M stands for Metrohm-defined types. The
placeholder xx stands for the number of sample beakers in a rack. The
numerical code y is reserved for special racks (unused as yet). User-
defined rack types can be created with a suitable PC software and intro-
duced into the instrument via the serial interface. The name of the rack type
may be chosen at will this way.
The Work position determines the height of the lift head, the position in
which a sample vial is heated. In this way the ideal position for every sam-
ple rack can be chosen dependent on the size of the vials. This work posi-
tion can be accessed directly in manual operation with the <END> key. In
a process sequence this can be programmed with “LIFT 1 work”.
The Rinse position serves to define the position of the lift head at which a
Rinse function (for the conditioning vessel) is to be performed. Thus, de-
pendent on the sample vessel, it is possible to select the ideal setting for
each sample rack. This can be programmed in a sequence with 'LIFT :1:
rinse mm'.
The Shift position determines the correct position of the lift 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 accessories due to turning maneuvers of the
rack. However, a prerequisite is that this shift position is correctly set. In a
process sequence the positioning of the lift to the shift position can be pro-
grammed with "LIFT 1 : shift mm".
The Special position is a further, user-defined positioned of the lift head. It
can be programmed in a sequence with 'LIFT :1 : Special mm'.