FDO-99E Fluorescence Method Dissolved Oxygen Analyzer Product Manual
Shandong Dongrun Instrument Science and Technology Co., Ltd. - ２- www.cndongrun.com
2、Product Outline
Fluorescence Method Dissolved Oxygen
Analyzer is based on the “quenching”
principle of certain substances to reactive
fluorescent in the physics, which detects the
concentration of dissolved oxygen or partial
pressure of oxygen in the water. Figure on
the right is the sensor measuring principle
diagram: The front-end measuring sensor
consists of two LEDs (emitting red-ray and
blue-ray separately), photoelectric detector
and the fluorescent cap.
The fluorescent material that in the front-end of fluorescent cap is a special kind of ruthenium metal
compounds. Fluorescent substances are coated below the polyester foil that allows gas molecules to pass.
The surface of polyester foil is coated with a layer of black ray insulation materials, in order to avoid
interference from ray of the sun or other rays in the water. When sensor works, the fluorescent material
was stimulated to produce red-ray when the modulated blue-ray is reaching. Due to the "quenching" effect
of oxygen molecules, the intensity of excitated fluorescence is related to time and oxygen concentration.
The higher oxygen concentration, the lower the intensity of excited fluorescence, and the shorter the time.
The stimulate red ray is detected by the photoelectric sensor, that compares with the reference light signal,
then it calculates the phase difference, and compares with internal calibration value, then oxygen
concentration is calculated, through the linearization and temperature compensation, outputs of the oxygen
density in the end.
Widely used in industrial and municipal sewage treatment plant: regulating reservoir, aeration tank,
aerobic/anaerobic digestion pool water monitoring, and water environment detection, such as river, lake,
sea, fishery, etc.
