Magnos206: Notes On Calibration - ABB EL3060 Series Operating Instruction

Magnos206: Notes on calibration

Calibration methods
Substitute gas calibration
Single-point calibration
EL3060 CONTINUOUS GAS ANALYZERS
Automatic calibration:
Manual calibration:
If test gases are not available for calibration, e.g. because they cannot be
filled in test gas cylinders or because their components are not compatible
with each other, the analyzer can be set ex works as per the order for cali-
bration with a substitute gas. In addition to the measuring range of the
sample component, a measuring range for the substitute gas component is
installed ex works; this is normally O
analyzer data sheet (see page 33).
The substitute gas calibration is a zero-point/end-point calibration of the
substitute gas component. The zero and end points of measuring range of
the sample component in the analyzer are then corrected by the values de-
termined in this calibration.
NOTE
Substitute gas calibration must always be used to calibrate all (sample gas
and substitute gas) components if the analyzer is set up for substitute gas
calibration. Zero-point/end-point calibration either in the sample compo-
nent or substitute gas measurement ranges leads to erroneous analyzer
calibration.
The long-term sensitivity drift of the Magnos206 is less than 0.05 % vol. O
per year. Thus only an offset correction needs to be routinely carried out in
the measuring ranges from 0–5 to 0–25 % vol. O
calibration can be conducted at each point on the characteristic curve since
a parallel shift of the curve is effected. Depending on the measurement task,
we also recommend that an end-point calibration is carried out at least once
a year.
Note: The sensitivity drift can amount to 1 % of the measured value per week
in the short-term.
Single-point calibration in measuring ranges with suppressed zero
point
The single-point calibration can also be carried out in a measuring range
with a suppressed zero point, provided that the suppression ratio is less
than 1:5. The O concentration of the test gas must be within the measuring
2
range.
Air pressure correction
The current atmospheric pressure must be considered for the single-point
calibration. This is carried out automatically if a pressure sensor (see page
26) has been installed in the analyzer.
| OI/EL3060-EN REV. A
Zero-point/end-point calibration or substitute gas
calibration (set ex works if a substitute gas com-
ponent is installed) or single-point calibration
Zero-point/end-point calibration or substitute gas
calibration (set ex works if a substitute gas com-
ponent is installed) or single-point calibration
in N . This setting is documented in the
2 2
2
. This so-called single-point
73
2