AO2000
CONTINUOUS GAS ANALYZERS | OI/AO2000-EN REV. B
55
Flammable, corrosive or toxic gases
Depending on which sample cell has been installed in the analyzer module,
the following application restrictions and notes must be observed:
Standard cell
Quartz cell
Safety cell
Suitable for
measurement of …
Non-corrosive gases
Corrosive gases, e.g. wet
Cl
2
wet HCl, H
2
SO
4
, SO
3
,
ozone
Corrosive gases, e.g. dry
HCl, dry COCl
2
(< 50 ppm
H
2
O)
Not suitable for
measurement of …
Highly corrosive gases, e.g.
gases containing chlorine,
H
2
SO
4
, SO
3
, fluorine com-
pounds
Fluorine compounds
Wet gases containing chlo-
rine, H
2
SO
4
, SO
3
, fluorine
compounds
Toxic gases
Housing purge
3)
with
sample component-free air
or with N
2
Housing purge
3)
with
sample component-free air
or with N
2
Sample cell purge
1)
with N
2
or with sample compo-
nent-free air under nega-
tive pressure and flow
monitoring; additional
monitoring for sample gas
traces possible
Corrosive gases
PTFE gas lines, housing
purge
3)
with sample com-
ponent-free air or with N
2
Housing purge
3)
with
sample component-free air
or with N
2
Sample cell purge
1)
with N
2
or with sample compo-
nent-free air under positive
pressure
2)
with flow mon-
itoring
Flammable gases
4)
Gas lines of stainless steel,
housing purge
3)
with N
2
Housing purge
3)
with N
2
Sample cell purge
1)
with N
2
1) "Purge
curtain"
2) p
e
= 7 to 20 hPa, 15 to 20 l/h
3)
≤
20 l/h
4) See the following section for further information
Flammable gases
The analyzer module is suitable for the measurement of flammable gases
and vapors under atmospheric conditions (p
abs
≤
1.1 bar, oxygen content
≤
21 vol.%). Temperature class: T4.
The sample gas may not be potentially explosive in normal operation; if it is
potentially explosive in the event of faults in the sample gas supply, then
only rarely and for a short time (corresponding to Zone 2).
Pressure in the sample gas feed path in normal operation p
e
≤
100 hPa; in the
event of faults in the sample gas supply, the pressure may not exceed the
maximum value of p
e
= 500 hPa.
For the measurement of flammable gases and vapors, the version with in-
ternal gas lines made of stainless steel should be selected and a housing
purge with nitrogen provided.
Prior to using the analyzer module, the corrosion resistance against the
sample gas must be tested.