Ocean Optics OOISensors - Manual (Page 84)

6: Hardware Data Sheets and Instructions
Temperature and the Oxygen Probe
Temperature affects the fluorescence decay time, the fluorescence intensity and the collisional frequency
of the oxygen molecules within the fluorophore – and therefore, the diffusion coefficient of oxygen.
Temperature also affects the solubility of oxygen in samples. The net effect of temperature fluctuations is
seen as a change in the calibration slope. It is best to maintain the sample at a constant (+/-3
° C)
temperature. If this is not practical, then you should calibrate your Fiber Optic Sensors System by using
the temperature compensation features and measuring temperature and oxygen concurrently. To monitor
the temperature of the sensing environment and compensate for temperature fluctuations, temperature
electrodes can now be used in conjunction with the oxygen probe. OOISensors Software corrects for
changes in data due to temperature fluctuations.
Photodegradation
Because the ruthenium may be subject to photodegradation, the total exposure to the excitation source
should be minimized. OOISensors Software can control the strobe of the LED so that it illuminates the
probe only during a measurement cycle, as long as the measurement cycle is greater than three minutes.
Ambient Light
Our miniature fiber optic spectrometers are very sensitive, and the oxygen probe will readily detect
ambient light. The probe must be shielded from ambient light to obtain reliable data. Install it in a closed
vessel, or shield the probe with a dark housing. An overcoat of silicone can be applied to the probe (at no
charge) to help reduce ambient light effects. However, the overcoat can slow the response time of the
probe from 20 to 90 seconds.
You can determine if ambient light is entering the probe by turning off the LED. The spectra in
OOISensors should appear flat, near the bottom of the scale.
Lifetime
Each oxygen probe is warranted for 1 year. Probes used in benign environments may last for a very long
time. However, severe biofouling, physical abrasion, and chemical etching of the glass may erode the
probes' sensing surface. Cleaning the probe and protecting it from damaging environments will extend its
life. After 1 year (or, if necessary, before 1 year), you can send your oxygen probe back to Ocean Optics
for re-conditioning and re-coating services (item code FOXY-RECOV or FOXY-RECOV-N for needle
probes).
Cleaning Oxygen Probes
You can use detergents to clean the probe. Using detergents to clean the probe does not necessitate
calibration.
Avoid cleaning oxygen probes with ketones (acetone and alcohols included) or organic solvents.
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