Functions and setup of the contrAA 600
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Edition 01/2014
contrAA 600
Thermal pretreatment, separating (ashing or pyrolysis of) distorting sample incidental
substances (matrix)
Atomizing the sample
Cleaning the graphite tube and preparing for the next measurement.
The operator optimizes these basic steps for each analysis problem with the ASpect CS
control software.
5.3.1
Graphite tube furnace
1
Fixed furnace part
2
Furnace jacket
3
Graphite tube
4
Movable furnace part
5
Insulating ring with inner electrode
Fig. 9
Graphite tube furnace
The furnace consists of a fixed and a movable furnace part. Both furnace parts are water-
cooled metal bodies, in which the ring-shaped graphite electrodes are located. The trans-
versely heated graphite tube is pneumatically pushed against the graphite electrodes via its
contact surfaces. There is another graphite component located between the metal bodies
that supports the electrodes, the furnace jacket. Together with the graphite electrodes it
forms an enclosure around the graphite tube, which stabilizes the thermal radiation condi-
tions of the graphite tube and also guarantees chemically inert conditions. When the mova-
ble furnace part is closed, the tube is pressed into the contacts, without coming into contact
with the furnace jacket.
The graphite tube is hermetically sealed in a protective gas atmosphere by the two graphite
electrodes and the furnace jacket. The furnace jacket has connections for beam passage,
furnace windows and protective gas supply as well as guides for automatic alignment of the
graphite tube when closing the furnace.
