Metrohm 774 Oven Sample Processor - Manual (Page 95)

5.6 Sample racks
774 Oven Sample Processor, Instructions for use 89
5.6 Sample racks
A sample rack is a turntable for accommodating sample vials. The standard
sample rack supplied with the 774 Oven Sample Processor can be de-
tached to insert samples and can then be fitted back on again. It is de-
signed for 35 sample vials whose dimensions must correspond to the
specifications so that these vials (22 mm Head Space Vials, order No.
6.2419.000) fit precisely in the oven's opening. The arrangement of the
sample positions on the rack is defined in a rack table. This rack table is
assigned to rack type M36-0 (= Metrohm standard rack with 36 positions).
Other rack types are scheduled for future further developments.
Each individual sample rack can be identified uniquely by a magnetic code.
Magnetic pins attached to the underside of the rack can be combined to
form a binary, six-digit code. The sample changer can thus detect auto-
matically what rack is fitted when the first rack position is beneath the lift.
You must press key <RACK> when changing a rack in order to move the
rack to the initial position. This activates unique recognition of the rack and,
thus, the correct position table.
When a sample series is started, the changer automatically moves the rack
first to initial position so that it is always ensured that the beaker positions
correspond to the internal position table of the relevant rack.
The standard racks provided by Metrohm are already equipped with a pre-
defined magnetic code for every rack type. If several racks of the same
type are used, the magnet rods can be arranged differently so that a unique
identification of a sample rack is possible, if this is desired.
The format of a magnetic code (example):
000001
i.e. only one magnet is inserted, outer right or bit 0
000101 i.e. two magnets are inserted, bit 0 and 2
63 different combinations are possible. The code 000000 stands for "no
code defined.”
In order to assign a certain sample rack for different applications, certain
properties or recognition data can be defined for up to 16 racks. This is
useful when a certain beaker size or the size of the sample series or a cer-
tain course of processing is to be predefined in an application.
Type Number
of vials Type of sample vessel Magnetic code
predefined Rack No.
pre-defined Article No.
M36-0 35 (+1) 22 mm Head Space Vials 000001 1 6.2419.000