ProMinent DULCOMETER diaLog DACb Assembly And Operating Instruction page 113

10.5.2.3 Calibration of the zero
point
Calibration of the zero point is only needed for
precise measurements at the lower end of the
measuring range (< 5% of the measuring
range).
CAL O2
Last calibration
Slope
100% (0.80 mA/ppm)
Zero point
4.00 mA
Calibration of the slope in air
Slope calibration by
reference measurement in water
Calibration of zero point
Fig. 77: Introduction: Calibration of the zero
point
1. Use OK to select the calibration
process: Calibration of the zero point.
The display appears as follows:
ð
CAL O2
Zero point 4.05 mA
Range
Accept with <CAL>
22.09.2019 14:22:33
3.95 mA - 4.15 mA
Fig. 78: Zero point
2. Position the sensor in an oxygen-free
environment e.g. in water with a slight
excess of sodium hydrogen sulfite and
wait until the signal is stable
3. Use CAL to accept
4. The display appears as follows if cali‐
bration is successful:
CAL O2
Calibration successful
Slope
Before calibration
After calibration
A
A2860
Zero point
Cancel with <ESC>
Fig. 79: Successful calibration
5.
Use CAL to confirm
n
Press ESC to cancel
n
6. The display appears as follows if cali‐
bration is unsuccessful:
CAL O2
Calibration not possible
Slope
Before calibration
After calibration
A
A2861
Zero point
Cancel with <ESC>
Fig. 80: Unsuccessful calibration
7. Use CAL to end
n
Press ESC to cancel
n
8. Check the sensor and installation once
again and repeat the calibration proce‐
dure.
Calibration
End with <CAL>
A2854
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End with <CAL>
A2855
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