AO2000 CONTINUOUS GAS ANALYZERS | OI/AO2000-EN REV. B 355
ZO23: Operating specifications
Linearity deviation Owing to the measurement principle, zirconium dioxide cells are base linear.
Repeatability < 1 % of the span or 100 ppb O
2
(whichever is greater)
Zero drift The zero point (reference point) is displayed if ambient air is present on the
sample gas side. The value for air 20.6 vol.% O
2
(for 25 °C and 50 % relative
humidity) may deviate due to aging of the cell.
< 1 % of the measuring range per week or 250 ppb O
2
(whichever is greater)
Sensitivity drift Depends on possible interfering components (catalyst poisons) in the sam-
ple gas and the aging of the cell.
For pure gas measurements in N
2
, CO
2
and Ar: < 1 % of the measuring range
per week or 250 ppb O
2
(whichever is greater)
Output fluctuation (2
σ)
< ±0,5 % of the measured value or 50 ppb O
2
(whichever is greater)
Flow influence ≤ 1 % of the measured value or 100 ppb O
2
(whichever is greater)
The flow rate is kept constant to ±0,2 l/h in the permissible range. The per-
missible range is 5 to 10 l/h.
Associated gas effect Inert gases (Ar, CO
2
, N
2
) have no effect. Flammable gases (CO, H
2
, CH
4
) in
stoichiometric concentrations to the oxygen content: Conversion of
O
2
< 20 % of the stoichiometric conversion. If higher concentrations of flamma-
ble gases are present, higher O
2
conversions must be expected. The concen-
tration of flammable gases in the sample gas may not exceed 100 ppm.
Temperature influence The effect of the ambient temperature in the permissible range of +5 to
+45 °C is < 2 % of the measured value or 50 ppb O
2
per 10 °C change in the
ambient temperature (whichever is greater).
Air pressure effect No effect through a change in air pressure; sample gas must flow out of the
outlet without back pressure.
Power supply influence 24 V DC ± 5 %: no effect
Position influence Position has no effect on the hard-mounted unit
T
90
time T
90
< 60 s for the alternation of 2 test gases in the measurement range
10 ppm with a sample gas flow rate = 8 l/h and electronic T90 time = 3 s (ap-
plies to an analyzer unit with 1 analyzer module)