Calibration - ABB ACF-NT Operator's Manual

Calibration

FTIR Spectrometer
Zero Spectrum
FTIR Spectrometer
Span Check
Test Gases for
FTIR Spectrometer
Span Check
42/23-572 EN Rev. 5
The zero spectrum is recorded automatically twice a day. It is used for zero and
sensitivity corrections. The zero spectrum is also named reference spectrum.
Zero calibration is described in detail in the "FTIR Spectrometer Zero Calibration"
section (see page 33).
The span check maintenance interval is 6 months. If a deviation greater than 4 %
results during span check, the span must be adjusted using test gases. Span
check is described in detail in the "FTIR Spectrometer Span Check" section (see
page 35).
Zero spectrum:
Span check: 1
2
3
Alternative for 2
Alternative for 3
4
5
 Before each test gas change, purge the test gas paths with the zero gas for at
least 10 minutes. In case of NH
avoid reactions with other gases.
 Setting and checking the water cross-sensitivity correction against the other
sample components must be performed using the cleaned instrument air
available in the analyzer system as carrier gas for the water vapor generator.
 For the measurement of HF, checking the water vapor cross-sensitivity must be
ensured:
 during initial start-up by the manufacturer's or the supplier's qualified
personnel,
 in the annual functional tests by an accredited measurement institute as per
EN 17025.
 The measured values are indicated in wet mg/Nm
correction is not required since sample gas and test gas are measured under
the same conditions.
Operator's Manual ACF-NT, ACF-NT V0309
Purified Air ("Zero Gas")
SO + CO + NO + rest N
2
HCl in N
2
NH in N
3 2
HCl + H O + air from evaporator
2
NH + H O + air from evaporator
3 2
H O in air from evaporator
2
HF + H O + air from evaporator
2
span check use this test gas as the last to
3
2
Supplied at test gas
port
Supplied directly to
sample conditioning
block or sample gas
line
3
. Pressure or temperature
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