A DS 4 20
| D I SS O LV ED OX YG EN P R O B E | O I/A DS 4 2 0 - EN R E V. A
11
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
Select
20
Press the
key (below the
Back
prompt).
The
Calibrate page
is displayed:
Calibrate
Menu
Exit
Select
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 sulphite.
Abort calibration
A calibration is aborted by pressing the
key below the
Abort
prompt displayed on the
Calibrate
pages (refer to the
transmitter Operating Instructions
).
The Calibration Log displays the message
Cal Aborted
– refer
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 probe response
If the output from the probe 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 probe configuration/recalibrate probe.
If the fault persists:
2
Clean the sensor cap and lens – refer to
If the fault persists:
3
Replace the sensor cap – refer to
.
If the fault persists:
4
Replace the probe.
