12
...4 Calibration
18 When zero calibration is complete, a results page is
displayed:
Calibrate
PV
2.31 %
Tmp
25.40 °C
Offset
0.041
Slope
0.954
Exit
19 Press the
key (below the Exit prompt).
The Calibrate page is displayed:
Calibrate
S1:
DO
Back
20 Press the
key (below the Back prompt).
The Calibrate page is displayed:
Menu
Calibrate
Exit
21 Press the
key (below the Exit prompt) to return to the
Operator page.
22 Once the calibration is complete, remove the sensor from
the chamber and rinse thoroughly to remove all of the
sodium sulfite.
A D S 4 2 0 | D I S S O LV E D OX YG E N S E N S O R | O I/A D S 4 2 0 - E N R E V. B
Select
Select
Abort calibration
A calibration is aborted by pressing the
prompt displayed on the Calibrate pages (refer to the
transmitter Operating Instructions OI/AWT420).
The Calibration Log displays the message Cal Aborted – refer
to
OI/AWT420
for Calibration Log entries.
Calibration timings
Stability period
The temperature and concentration readings are monitored for
up to 10 minutes until a stable reading is achieved. When
stability is achieved, the calibration (slope and offset) values
are determined.
Slow sensor response
If the output from the sensor does not stabilize during the
Stability Period the calibration is not accepted and a Cal Failed
diagnostic is displayed, the Calibration Log is updated with a
Cal Failed message.
Calibration troubleshooting
Slow sensor calibration or no response to dissolved oxygen
changes
1 Check sensor configuration/recalibrate sensor.
If the fault persists:
2 Clean the SmartCap and lens – refer to Maintenance on page
13.
If the fault persists:
3 Replace the SmartCap – refer to Spares on page 18.
If the fault persists:
4 Replace the sensor.
key below the Abort