AO2000
CONTINUOUS GAS ANALYZERS | OI/AO2000-EN REV. B
127
Gas path and housing initial purge
Purge before commissioning
The gas paths and if necessary, the system housing should be purged prior
to starting the gas analyzer.
Firstly this ensures that the gas paths and system housing are free from
contaminants e.g. corrosive gases, and accumulations of dust on start-up.
Secondly this prevents any explosive gas/air mixture present in the gas
paths or system housing being ignited when the power supply is connected.
Purge gas
Nitrogen or instrument air should be used as a purge gas.
Purge gas flow rate during initial purge
The purge gas flow and the duration of the purge process depend on the
volume to be purged (see the following table). If the purge gas flow is lower
than specified, the duration of the purging must be extended accordingly.
Volume to be purged
Purge gas flow rate Duration
Gas path
100 l/h (max.)
approx. 20 s
Central unit with or without analyzer
module
200 l/h (max.)
approx. 1 h
Analyzer separately: Caldos25, Caldos27,
Magnos206, Magnos28, Magnos27
200 l/h (max.)
approx. 3 min
NOTE
The purge gas flow rates given in the table only apply to the initial purge.
Other values apply during operation (see page 136).
ATTENTION
Purge gas can escape from the housing if there are any leak points.
When using nitrogen as the purge gas, take all required precautions
against suffocation.
The purge gas flow must always be restricted upstream of the purge gas
inlet! If the purge gas flow is not restricted until after the purge gas out-
let, the full pressure of the purge gas will affect the housing seals which
can destroy the operator panel keypad!
