System design
30 Edition 01/2016 multi EA 4000
measuring gas hose connection
gas introduction into the measuring cell
indicator electrodes (Ag)
generator cathode (Pt)
Fig. 12 Combination electrode for measuring cell
4.4.2 Combustion tube and measuring gas drying
A quartz tube is used as combustion tube during Cl detection. The oxygen for the combus-
tion is supplied via a bypass in the quartz tube. The measuring gas is inducted at the side
connection of the quartz tube and passed via the drying stage to the Cl module. The gas
airlock, which is supplied with argon, prevents the measuring gas from escaping from the
inlet of the combustion tube The end of the combustion tube is sealed with quartz wool to
prevent dust from entering the hose system of the multi EA 4000.
bypass for oxygen supply
connection socket for oxygen
4 measuring gas outlet with boat connection
5
argon supply at the gas airlock
Fig. 13 Quartz combustion tube with gas airlock
Hydrogen chloride (HCl) has a high affinity for water and is therefore dissolved in its conden-
sates. During analysis this behavior causes too low results or memory effects. To prevent
condensation, the measuring gas must be dried immediately after it leaves the combustion
tube. Concentrated sulfuric acid is used as a desiccant. Two special sulfuric acid containers
are used dependent on whether the method includes measuring gas splitting or not.
When using the sulfuric acid container with split outlet, an additional safety container is in-
stalled in the gas path. This collects sulfuric acid that might be drawn out of the sulfuric acid
container.
To Next Page
Loading...
Need help?
General
