ProMinent DULCOMETER D2C Operating Instructions Manual page 12

Operating Menu / Description
Initial value
Buffer values pH 7
pH 4
Error message
Buffer distance too small
pH zero point low
pH zero point high
pH slope low
pH slope high
Measured value pH unsteady
Calibration of the chlorine probe
The calibration (slope calibration) of the chlorine probe uses the DPD method. When starting calibration,
the frozen measuring value is proposed; this value may be adjusted to the measured DPD value using the
Up and Down buttons. A calibration will only be possible if the DPD value is ≥ 2% of the measuring range.
During calibration, control function and metering are maintained. After successful calibration, all fault
determinations relating to the measuring value are started again.
With a measuring range adjusted to 0 - 0.5 ppm, the zero point may be calibrated in the entire operating
menu in addition to the slope. The zero point calibration should be performed under realistic condition with
chlorine-free water. In this case, control will be stopped and metering will be reduced to the set base load.
The output 0/4...20 mA (measuring value) will be frozen.
IMPORTANT
The measuring range of the chlorine probe must correspond to the adjusted measuring
range of the DULCOMETER
measuring range (see page 19) must be done prior to calibration. If the measuring range is
altered, all settings are reset to the factory settings.
12
Possible values
Increment
0.01 pH
Condition Effect
During calibration procedure:
∆Buffer <2 pH Recalibrate buffer 2!
Return to permanent display:
< -60 mV Basic metering load
< +60 mV
<45 mV/pH
>65 mV/pH
® D2C (factory setting 0 - 2.00 ppm). A possible alteration of the
Lower value Upper value
-2 pH 16 pH
Warning, old zero point and slope retained
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Remarks
Error messages when both buffers
too close (<2 pH-values)