Calibrating The Measured Value For The Measured Variable Do - ProMinent DULCOMETER Assembly And Operating Instructions Manual

Calibrating the controller
Incorrect calibration
Should the result of the cal‐
ibration lie outside the
specified tolerance limits,
an error message appears.
In this case the current cal‐
ibration will not be applied.
Check the prerequisites for
the calibration and clear
the error. Then repeat the
calibration
88
Calibrating the measured
9.5
value for the measured vari‐
able DO
Specify the calibration interval
The calibration interval depends strongly
on:
the application
n
the installation location of the sensor
n
If you wish to calibrate a sensor for a spe‐
cial application and/or a special installa‐
tion location, then you can determine the
calibration intervals using the following
method. Check the sensor, e.g. one
month after its commissioning:
1. Take the sensor out of the medium
2. Clean the outside of the sensor with
a damp cloth
3. Then gently dry the sensor dia‐
phragm, e.g. using a paper towel
4. After 20 minutes, measure the
oxygen saturation index in the air
5. Protect the sensor against external
influences such as sunlight and
wind
ð Now decide dependent on the
result:
Amperometric sensor: If the
measured value does not lie
with 102 ± 2 %SAT, you must
calibrate the sensor.
If the value is within the set‐
point range, then you can
extend the calibration interval.
Repeat this process monthly
and from the results determine
the optimum calibration interval
for your application.