The fluorescent dissolved oxygen sensor is designed for the continuous measurement of dissolved oxygen in water.
Some examples include –
- measurement and the control of oxygen in aeration basins,
- monitoring oxygen in the effluent from a sewage treatment plant;
- measurement and control of the oxygen content in public water supplies;
- measurement and control of oxygen in fish farms; and
- the oxygenation of drinking water.
Based on the ability of selected substances it acts as dynamic fluorescence quenchers. The fluorescent indicator is a special platinum porphyrin complex embedded in the gas permeable foil which is exposed to the surrounding water. A black optical isolation coating projects the complex from direct incoming sunlight and fluorescent particles in the water.
The sensing foil is pushed against a sapphire window by a screw mounted in the securing plate. The foil is excited by modulated green light and the phase of a returned red light is measured. The duration and intensity of the fluorescence are directly dependent on the amount of oxygen in the surrounding.
