Operating instructions

Aztec ADS430 | Optical dissolved oxygen probe | OI/ADS430–EN Rev. A 17
7 Maintenance
7.1 Cleaning the sensor cap
1. Isolate the transmitter and remove the probe from the
process.
Referring to Fig. 7.1:
2. Unscrew shroud
A from probe body B.
3. Rinse sensor cap
C with clean water from a spray bottle.
4. Gently wipe sensor cap
C with a soft-bristled brush or, if
biofouling is present, a soft cloth.
If necessary, use a grease remover to remove grease.
5. Refit shroud
A by screwing it onto probe body B.
7.2 Cleaning the optical lens
1. Isolate the transmitter and remove the probe from the
process.
Referring to Fig. 7.2:
2. Unscrew shroud
A from probe body B.
3. Grip sensor cap
C between your thumb and forefinger
and carefully slide it off of probe sensor
D.
4. Gently wipe optical lens
E with a lens cloth (not supplied).
5. Refit shroud
A by screwing it securely onto probe
body
B.
7.3 Cleaning the probe body
1. Isolate the transmitter and remove the probe from
the process.
Referring to Fig. 7.3:
2. Gently scrub shroud
A and probe body B with a
soft-bristled brush or nylon dish scrubber.
If necessary, use a grease remover to remove grease or
other matter from the body, or soak in vinegar and
deionized water to remove mineral deposits or extensive
fouling.
7.4 Diagnostic messages
The table below shows sensor-specific icon types, diagnostic
messages and possible causes / suggested remedial action.
Fig. 7.1 Cleaning the sensor cap
IMPORTANT (NOTE)
— DO NOT touch the cap end of sensor cap
C.
— Do not allow moisture or atmospheric humidity
inside sensor cap
C.
— Do not wet lens area
E with water or any
solution. Use only the supplied lens cloth
for cleaning.
Fig. 7.2 Cleaning the optical lens
IMPORTANT (NOTE)
— Ensure shroud
A is secured in place before
cleaning.
Fig. 7.3 Cleaning the probe body
IMPORTANT (NOTE)
— The diagnostic icons in the following tables
conform to NAMUR 107.
— For transmitter-specific diagnostics messages,
refer to AWT440-EN.
Diagnostic Icon NAMUR Status
Out of specification
Maintenance required
Check function
Icon Message Possible cause / suggested action
Cap Expired
(S1, S2, S3, S4)
The optical DO sensor cap has reached
or exceeded its expiry date. The cap
may continue operating but its
accuracy will degrade and cannot be
guaranteed to meet specification.
Replace Cap
The optical DO sensor cap will reach
expiry date in 4 weeks or less.
Replace sensor cap.
Cap Removed
The sensor cap has been removed. The
reading will drop to zero. Ensure sensor
cap is fitted onto the probe tip.