ABB AO2000 Series, Operating Instructions Manual

Page: 349 / 362

AO2000 CONTINUOUS GAS ANALYZERS | OI/AO2000-EN REV. B 349
Limas11 IR, Limas21 UV: Operating specifications
Linearity deviation ≤ 1 % of span
Repeatability ≤ 0.5 % of span
Zero drift ≤ 2 % span per week; for ranges smaller than Class 1 to Class 2: ≤ 1.5 % span
per day (Recommendation: daily automatic zero-point calibration)
Sensitivity drift ≤ 1 % of the measured value per week
Output fluctuation (2 σ )
Limas21 UV: ≤ 0.5 % of span at electronic T90 time = 10 s
Limas11 IR: ≤ 0.5 % of span at electronic T90 time (static/ dynamic) = 60/5 s
for ranges smaller than Class 1 to Class 2: ≤ 1 % of span
Detection limit (4
σ
) ≤ 1 % of the span; for ranges smaller than Class 1 to Class 2: ≤ 2 % of span
Flow influence Flow rate in the 20 to 100 l/h range: within the detection limit
Associated gas effect /
cross sensitivity
The knowledge of the sample gas composition is necessary for the analyzer
configuration. Selectivity measures to reduce associated gas effect (option-
al): Installation of filter cells or internal electronic cross-sensitivity correction
or carrier gas correction for a sample component by other sample compo-
nents measured with the Limas11 IR or Limas21 UV
Temperature influence At zero point: ≤ 1 % of span per 10 °C, for measurement ranges smaller than
Class 1 to Class 2: ≤ 2 % of span per 10 °C
On sensitivity: ≤ 1 % of the measured value per 10 °C
Sample cell temperature regulation to 60 °C; Ambient temperature in per-
missible range
Air pressure effect At zero point: no influence effect
On sensitivity with pressure correction with an integral pressure sen-
sor:
≤ 0.2 % of the measured value per 1 % air pressure change
The pressure sensor is located in the sample gas path if hoses are used as
the internal gas lines. The connection of the pressure sensor is led to the
outside if the internal gas lines are executed as tubes. Pressure sensor
working range: p
abs
= 600 to 1250 hPa
Power supply influence 24 V DC ± 5 %: ≤ 0.2 % of span
T
90
time T
90
= 4 s for measurement cell length = 262 mm and sample gas flow = 60 l/h
without signal damping (low pass filter). Low-pass time constant adjustable
from 0 to 60 s