Optical dissolved oxygen measurement

Environmental Instruments has developed the Fluoroprobe, an optical-based sensor for oxygen measurement and control in the environmental, biotech and aquaculture industries.

The FL-3 is a release of the electronics that drive the sensor technology. The sensor remains unchanged and the new microprocessor and keypad makes set-up and use much easier and now includes a three-line display showing DO value, temperature and elevation.

Inside the sensor, a blue light is directed onto a silicon tip impregnated with a special material that fluoresces in the presence of oxygen. The fluorescence is the reflection of the blue light as red light. The degree of fluorescence changes with the concentration of oxygen. The concentration of red light reflected is a direct measurement of the concentration of oxygen present at the sensor tip.

As an optical-based measurement there are no electrolyte solutions or membranes to replace and the requirement for routine maintenance is eliminated. The measurement does not consume oxygen and so does not suffer the fouling problems that occur with the other oxygen measurements. The sensor materials are UV resistant with good chemical resistance to provide a long operational life. The Fluoroprobe's long-term stability eliminates the requirement of regular calibration.