348  AO2000 CONTINUOUS GAS ANALYZERS  |  OI/AO2000-EN REV. B 
 
 
 
Fidas24, Fidas24 NMHC: Operating specifications 
The following data only applies if all the influence variables (e.g. flow, tem-
perature and air pressure) are constant. These apply for the measuring 
ranges ≥ 50 mg org. C/m
3
; for smaller measuring ranges these only apply if 
they set are at the factory per customer order. 
 
Linearity deviation  ≤ 2 % of the measurement span up to 5000 mg org. C/m
3
,  
this value applies in a (calibrated) measuring range 
Repeatability  ≤ 0.5 % of the measuring range 
Zero-point and sensitivity 
drift 
≤ 0.5 mg org. C/m
3
 per week 
Output fluctuation (2 σ) 
≤ 0.5 % of span at electronic T90 time = 20 s, not smaller than 10 µg 
org. C/m
3
 
Detection limit (4 
σ) 
≤ 1 % of span at electronic T90 time = 20 s, not smaller than 20 µg org. C/m
3
 
Oxygen dependence  ≤ 2 % of measured value for 0 to 21 vol.% O
2
 or ≤ 0.3 mg org. C/m
3
, whichever 
is greater 
Temperature influence  Ambient temperature in permissible range: 
on zero point and on sensitivity: ≤ 2 % per 10 °C in the measurement range 
0 to 15 mg org. C/m
3
 
Power supply influence  24 V DC ± 5 %: ≤ 0.2 % of span or   
230 V AC ± 10 %: ≤ of span 
T
90
 time Fidas24  T
90
 < 1.5 s at a sample gas flow rate = 80 l/h and electronic T90 time = 1 s 
T
90
 time Fidas24 NMHC  T
90
 < 2.5 s via bypass, T
90
 < 3 s via converter at sample gas flow = 80 l/h and 
electronic T90 time = 1 s 
Switch-over time   
(Fidas24 NMHC) 
between bypass and converter typically 20 s, depending on measurement 
range