Measuring and control behaviour
of the controller during calibration
During calibration the actuating out‐
puts are deactivated. Exception: a
basic load or a manual control vari‐
able has been set. This remains
active. The measured value output
[standard signal output mA] is frozen,
corresponding to its settings in the
mA output menu.
When calibration/testing has been
completed successfully, all of the
error checks relating to the measured
value are restarted. The controller
saves all the determined data for zero
point and slope upon a successful
calibration.
The measured value frozen at the start of
calibration is suggested as a reference
value. The reference value can be set
using the arrow keys. Calibration is only
possible if the reference value is ≥ 2 % of
the measuring range of the sensor.
NOTICE!
Prerequisites for correct calibration of
the sensor slope
– The reference method needed is
used, depending on the feed
chemical used (e.g. DPD 1 for
free chlorine).
– The run-in period for the sensor
has been complied with; refer to
the operating instructions for the
sensor.
– There is permitted and constant
flow at the in-line probe housing
– There is temperature balance
between the sensor and the
sample water
– There is a constant pH value in
the permitted range
Material required for calibration of
amperometric sensors:
n A reference method suitable for the
measured variable in question
Calibration
86
To Next Page
Loading...
