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4
Optical Dissolved Oxygen Probe
4.1
Probe Structure
The instruments DO803 optical dissolved oxygen probe has a cable length of 3m and built-
in temperature sensor for automatic temperature compensation. The electrode structure is
shown in Fig.-6
1. Bottom cover of the calibration sleeve
5. Locking cap
2. Sponge for water storage
6. Optical DO electrode
3. Sensor cap
7. O-ring
4. Calibration sleeve
Immersion line:
The tested solution should be above this line
4.2
Probe Maintenance
The sensor cap of the optical DO electrode must be kept in a moist environment. If the
surface coating of the sensor cap dries out, the reading will be unstable, or the response
rate will be slow. The electrode calibration sleeve is used to store the probe.
(A) Short-term storage (less than 30 days): The probe head is kept in the calibration
sleeve. Always keep the sponge inside the calibration sleeve moist. Several drops of
clean water should be added to a dry sponge
(let the sponge be damp, but not
dripping),
and tighten the lock cap, so that the sensor cap is kept in the moist-
saturated air.
(B) Long-term storage (greater than 30 days): The probe head is kept in the calibration
sleeve. Check whether the storage sponge is moist every 30 days or user can store
the electrode in a beaker containing clean water.
(C) Before the first use, unscrew the calibration sleeve to check if the sponge is damp. If
the sponge is dry or if the electrode is exposed to dry air for more than 8 hours, the
surface coating of the sensor cap may be dried out. So the electrode should be
Fig.-
6
