Endress+Hauser TOCII CA72TOC - Calibration

Maintenance TOCII CA72TOC
84 Endress+Hauser
7.8 Calibration
7.8.1 Adjusting the analyzer
This section describes how the analyzer is adjusted.
The analyzer is adjusted using two-point adjustment. Two different standard solutions are measured
for this purpose. These standard solutions are connected in the analyzer.
Adjustment procedure:
1. The basic line is measured.
2. The analyzer measures the concentration of standard C1.
3. The basic line is measured.
4. The analyzer measures the concentration of standard C2.
5. The offset X
0
and the slope K
p
are calculated from these values.
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Fig. 43: Calculation of the measuring signal
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Fig. 44: Calculation of the offset X
0
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Fig. 45: Calculation of the standardized slope Kp
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Fig. 46: Adjustment curve
ΔCO
2(C1)
= CO
2
concentration of the measurement of standard C1.
ΔCO
2(C2)
= CO
2
concentration of the measurement of standard C2.
The offset and the reciprocal standardized slope of the adjustment curve (measuring signal per
concentration) are saved in the maintenance record log under ADJUSTMENT CONSTANTS.
Analyzer adjustment can be started in three ways:
• Activated manually
• Activated remotely
• Activated automatically
Measuring signal =
CO
2(C)
=CO -CO
2(dose) 2(base line)
X=
0
CO - C
2(C1) 1
CO -
2(C2)
CO
2(C1)
(C -C)
21
Kp =
CO - X
2(C2) 0
Kp =
C
2
actual dosing volume
0.3125
Kp
X
0
C
1
C
2
Concentration
Measured signal