ProMinent DULCOTEST ICT 2 Instrucciones De Servicio página 42

Commissioning
42
b) Calibration with calibration solution
Important precondition: You need a calibration solution of the
corresponding accuracy (better than 1 % absolute reproducibility;
at least 500 ml).
CAUTION
Take the necessary precautions when dismantling the sensors
(safety gear...)!
IMPORTANT
• Handle the calibration solution with extreme care. Adequate
accuracy will not otherwise be achieved.
• Ensure cleanliness and avoid carry-over or evaporation of the
liquid (evaporation even after 20 min. can be too much).
Dismantle the sensor from the tubing
Wipe deposits off the sensor and rinse
then rinse the sensor with deionised water until the displayed
conductivity value is less than 20 μS/cm
Dry the sensor thoroughly (including inside the bore of the sensor
tip)
Place the sensor in a clean standard glass beaker along with the
calibration solution
Stir with the sensor until the air bubbles have been expelled from
the bore and the displayed conductivity value on the
®
DULCOMETER D1C is stable
Fix the sensor in the centre of the beaker so that the sensor tip is
at least 30 mm from the glass in all directions (preferably 40 mm).
The sensor tip must be immersed at least 30 mm (top edge of
sensor tip).
Wait 20 min. until the temperature has equalised between the
sensor and calibration solution (1 °C temperature deviation equals
approx. 2 % measurement error)
Set the temperature coefficient α at the DULCOMETER
the value specified by the manufacturer for the calibration solution
(e.g. approx. 1.86 %/K for KCI solutions around 25 °C)
Select "install. factor setting?" in the setting menu, note the set
installation factor and then set to 1.00
®
D1C to
ProMinent ®