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)