Preconditions
• Constant flow to the in-line probe housing (see section 15 "Technical Data").
• Constant sample water temperature.
• Same sample water and sensor temperatures (wait approx. 15 min.).
Zero point calibration
If a ProMinent controller is being used to operate the sensor there is no need
for zero point calibration. Zero point calibration should be carried out,
however, if operating the sensor in the lower measurement range, or if using
the 0.5 ppm variant.
Preconditions
• The sensor has been run in (see section 7.1 "Run-in Period").
• Flow to the in-line probe housing is constant and complies with section 15
Slope test
Repeat calibration after 1 day!
NOTE
Calibration at high temperatures
As chlorine dioxide, in contrast to chlorine, is only physically dissolved in
water, it evaporates out of the liquid very quickly at high temperatures
(> 30 °C). We therefore recommend 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.
®
ProMinent
"Technical Data".
Insert the sensor into a container of clean, ozone- and ClO
Stir with the sensor until the measured variable displayed at the controller
has remained stable for 5 min.
Calibrate the controller to zero in accordance with the operating
instructions.
Replace sensor into the in-line probe housing in accordance with section
6 "Installation" (in-line probe housing: DLG).
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.
Operation
-free water.
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