Pr
o
Minent
®
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calibration pH
zero p.: -3,1 mV
slope at 25
°
C
58.32 mV/pH
calibration?
calibration pH
buffer 1: 7.00 pH
mea. val: 7.00 pH
signal: -3,1 mV
calibration pH
calib. 1 active
please wait!
-3.1 mV
calibration pH
buffer 2: 4.00 pH
mea. val: 4.00 pH
signal: 157 mV
calibration pH
calib. 2 active
please wait!
157 mV
calibration pH
zero p.: -3,1 mV
slope at 25
°
C
53.70 mV/pH
calibration pH
probe in buffer
buffer: 7.00 pH
temp.: 25
°
C
calibration pH
probe in buffer
buffer: 4.00 pH
temp.: 25
°
C
A
B
Slope
Test
Determine the chlorine dioxide content in the sample water using an appropriate measurement
device (e.g. DPD-1).
Set the resulting value at the controller in accordance with the operating instructions.
Repeat calibration after 1 day!
NOTE
Calibration at high temperatures
As chlorine dioxide, in contrast to chlorine, is only physically dissolved in water, it evapo-
rates out of the liquid very quickly at high temperatures (> 30 °C). We therefore recom-
mend that you act quickly when carrying out the DPD measurement. There should be no
more than 1 min. between the sample extraction and the addition of reagents. Therefore
the reagent should be added directly at the sample extraction point and measurement
should follow as soon as possible afterwards in the laboratory.
Calibration
Calibration of the DULCOTEST
®
Sensor PHEP or PHER for pH
pH
Sensor
Since pH sensors are subject to certain manufacturing tolerances, they must be tuned to the
pertinent pH transmitter. The adjustment intervals depend on relevant operating conditions. They
can vary from a few days to up to 8 weeks.
Having connected the sensor to the transmitter by means of the sensor cable (taking care that
connectors and cable remain absolutely dry), dip the sensor into a pH 7 standardizing solution
and adjust transmitter exactly to read this value.
Remove the sensor, rinse it with water, preferably distilled water, and dry it by swabbing it with
soft, non-fl uffi ng tissue paper.
IMPORTANT
Do not rub since this might cause static electricity and false readings.
Immerse the sensor in a buffer solution differing by a least 2 pH from pH 7 and calibrate after the
value on the display has stabilised. If within 30 seconds a steady-state value is not produced or
calibration has proved impossible, clean sensor and repeat calibration. If again unsuccessful,
replace sensor with a new one.
Calibration of the pH Sensor
The calibration of the pH sensor uses a two-point calibration method (zero point, slope). As
buffer pH 7 (zero point calibration) and pH 4 (slope calibration) are factory-set. If other buffers are
to be used, the defaults in the complete operating menu (menu A, B) may be altered. During
calibration control is stopped and metering is reduced to the set base load. The output
0/4...20 mA (meas ur ing value) will be frozen. After successful calibration, all fault determinations
relating to the meas ur ing value are started again. The current sensor data (zero point/slope) will
be displayed.
pH/Chlorine Dioxide
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24.02.2009 11:56:11 Uhr
