Metrohm 789 Robotic Sample Processor XL - Manual (Page 99)

3.7 Sample racks
Metrohm Sample Processor, Operation 91
Racks 48 cm diameter (for 789 XL models only)
Article no. /
Rack type
No. of
samples
Type of sample vessel Vessel
diameter
Magnet code
(predefined)
6.2041.800 100 *) 75 mL Metrohm titration beaker 35 mm 000100
6.2041.810 34 *) 150 mL beaker or
200 mL disposable beaker (Euro) 55 mm 001001
6.2041.820 28 *) 250 mL Metrohm titration beaker 65 mm 010010
6.2041.830 28 *) 200 mL PP sample beaker 55 mm 100010
6.2041.840 59 *) 120 mL PP sample beaker 42 mm 001100
*) can only be used with 786 Swing Head
On request we can supply further user-defined racks that can be de-
fined in the instrument via PC software. The beaker positions can be ar-
ranged as required.
3.7.2 Magnet codes
Each individual sample rack can be identified unambiguously by a
magnet code. Magnet pins attached to the base of the rack (see Fig. 5)
can be arranged to form a 6-place binary code. The Sample Processor
can then automatically recognize which rack has been placed on it if
the rack is located at the starting position after initialization.
When a rack is changed it should first be brought to the starting posi-
tion by pressing the key. In this way the rack can be posi-
tively recognized, which makes correct beaker positioning possible.
Each type of rack is assigned to an internal position table, in which the
angle of rotation and distance to the center of the rack is defined for
each rack position.
When a sample series is started the Sample Processor automatically
moves the rack to the starting position so that its magnet code can be
read off. This ensures that the beaker positions coincide with the inter-
nal position table of the current rack.
The standard racks supplied by Metrohm are already provided with a
predefined magnet code for each type of rack. If several racks of the
same type are in use then the magnet pins can be arranged differently
to allow the unambiguous identification of each individual rack.
Magnet code format (examples):
000001 i.e. only one magnet inserted, Bit 0
000101 i.e. two magnets inserted, Bit 0 and 2
63 different combinations are possible. Code 000000 stands for "no de-
fined code".