Incorrect calibration
An error message appears if the result of the cali‐
bration lies outside the specified tolerance limits. In
this case, the current calibration is not applied.
Check the prerequisites for calibration and clear
the error. Then repeat calibration.
7.
Transfer the result of the calibration into the controller
memory by pressing
ð
The controller displays the continuous display again and
operates with the results of the calibration.
7.3.1.1.4 Calibration of the pH Sensor (CAL) by
[Data Input]
Data input
Using the
[Calibration of the pH sensor (CAL) by data input]
calibration method, the sensor's known data is
entered into the controller. Calibration by data
input is only as accurate and reliable as the
method with which the data was determined.
The sensor data must have been determined in
real-time. The more up-to-date the sensor data is,
the more reliable is this calibration method.
Correct sensor operation
–
Correct measuring and metering is only pos‐
sible if the sensor is working perfectly
–
Refer to the sensor's operating instructions
Measuring and control behaviour of the controller
during calibration
During calibration the actuating outputs are deacti‐
vated. Exception: a basic load or a manual control
variable 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 suc‐
cessfully, 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.
Tab. 5: Valid calibration values
Evaluation
Zero point
Slope
Very good
-30 mV … +30 mV
56 mV/pH … 60 mV/pH
Good
-45 mV … +45 mV
56 mV/pH … 60,5 mV/pH
Acceptable
-60 mV … +60 mV
55 mV/pH … 62 mV/pH
Continuous display ➨
Start Up
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