Installation conditions
contrAA 600
Edition 01/2014
21
The introduction of an additional gas during the pyrolysis step (e.g. air or oxygen) can accel-
erate the ashing of the sample, i.e. the removal of the matrix components. The additional gas
is fed in through the "Gas Additional" connection on the rear of the device.
The gas pressure at the spectrometer must be between 0.6 and 0.7 MPa.
CAUTION! PRESSURE CYLINDERS
If the inert gas is supplied by pressure cylinders, these must be secured to the wall in an
upright position with cylinder mounts outside the laboratory space.
The required pressure reducing valve for the inert gas cylinder and the argon pressure
tubing are supplied. The standard tube length is 5 m. If other tube lengths are preferred,
please contact the customer service department at Analytik Jena AG.
Recommended inert gas
Inlet pressure
Consumption
Recommended for graphite tube
operation:
Argon 4.8 or superior
Permitted components:
Oxygen
≤
3 ppm
Nitrogen
≤
10 ppm
Hydrocarbons
≤
0.5 ppm
Humidity
≤
5 ppm
6 - 7 bar
Max. 2 L/min (depending on
the temperature-time pro-
gram)
Table 2
Gases in the graphite tube technique
4.5
Exhaust unit
SWITCH ON THE EXHAUST UNIT DURING OPERATION!
Do not operate the contrAA 600 without an exhaust unit!
Direct waste air to atmosphere and avoid blockages!
The exhaust unit should remove any ozone. Ozone is caused by the reaction of air and UV
radiation from the xenon lamp and the graphite tube furnace. Use an exhaust unit made of
heat- and corrosion-proof material. The first 6 m of the exhaust unit should be made of
metal.
Parameters
Properties
Material
V2A
Exhaust performance for graphite tube
Approx. 1 m
3
/min
Hood opening
approx. 200 × 200 mm
2
Distance to the upper edge of the device
Approx. 200 to 300 mm
Tube diameter
Approx. 100 to 120 mm
Table 3
Exhaust unit requirements
