Metrohm 838 Advanced Sample Processor Installation Instructions - Manual (Page 66)

3.7 Sample racks
60 Metrohm 838 Advanced Sample Processor, Installation
3.7.2 Magnetic codes
Each individual sample rack can be uniquely identified by means of a
magnetic code. Magnetic pins on the underside of the rack (see Figure
8) can be combined to form a binary, six-digit code. The Sample Proc-
essor can thus automatically detect what rack is fitted.
When changing the rack, it should first be moved to initial position by
pressing the key (if a keypad is connected) or the instrument
should be switched off and then on again. This allows unique detection
of the rack and, thus, correct beaker positioning. An internal position
table defining the angle of rotation and the distance from the centre of
the rack is assigned to each rack type.
When a sample series is started, the Sample Processor automatically
moves the rack first to initial position in order to read out the magnetic
code. This always ensures that the beaker positions correspond to the
internal position table of the fitted rack.
The standard racks supplied by Metrohm already feature a predefined
magnetic code for each type. If several racks of the same type are
used, the magnetic pins may be arranged differently so as to allow
unique identification of a sample rack.
Magnetic code format (example):
000001 , i.e. only one magnet is fitted, bit 0
000101 , i.e. two magnets are fitted, bits 0 and 2
63 different combinations are possible. Code 000000 means "no code
defined".