UNION Instruments GmbH
INCA Analyzer Series
– Instruction Manual
Calibration
Page 31 of 59
5
C
ALIBRATION
5.1
Calibration
The analyzer is pre-calibrated by the manufacturer. In the field the analyzer can be re-
calibrated using special calibration gases. The calibration gas needs to be connected to the
analyzer for manual calibration. For automatic calibration setup (e.g. every week), a
calibration gas has to be connected permanently to the analyzer‟s calibration gas inlet
Warning
The gas inlet pressure must not exceed 20 mbar (0.29 psi).
5.1.1
Type of calibrations
There are two types of calibrations:
1. Calibration using purge gas (i.e.
purge gas calibration
)
2. Calibration using calibration gases (simply referred to as
calibration
)
Gases used in
calibration process
(codes)
Composition
CO
2
CH
4
H
2
S
O
2
N
2
Purge gas (S)
--
--
--
20.9 vol.%
80.1 vol.%
Calibration gas A1 (A1)
48 vol.%
52 vol.%
25 ppm
--
--
Calibration gas B1 (B1)
--
100 vol.%
25 ppm
--
--
Calibration gas C (C)
100 vol.%
--
--
--
--
Table 4: Example of calibration gases
Through the calibration process, calibration points of each sensor measured and determined.
Depending on the type of sensors used in the analyzer, a purge gas (usually air, 20.9 vol.%
O
2
; 80.1 vol.% N
2
) and one or more calibration gases are required for a complete calibration
process. Table above shows an example of gases which are used in to calibrate the sensors.
The table above shows an example of gases which are used to determine calibration points
of a particular type of analyzer. The analyzer has the following measurement ranges:
carbon dioxide (CO
2
)
0 - 100
vol.%
methane (CH
4
)
0 - 100
vol.%
hydrogen sulfide (H
2
S)
0 - 10000
ppm
oxygen (O
2
)
0 - 25
vol.%
