Optical DO sensor
The operating principle of the optical dissolved oxygen sensor is based on the principle of fluorescence burst quenching. The fluorescent cap inside the sensor contains oxygen-sensitive labelled molecules that fluoresce when excited by light from an LED. The detected fluorescence signal is converted into a dissolved oxygen value by internal signal processing. The sensors typically contain indicators for saturated oxygen, mg oxygen and water temperature, and automatic temperature compensation via an inbuilt temperature sensor ensures the accuracy of the measurement. Unlike traditional electrochemical sensors, optical method sensors do not consume oxygen during measurement, require no electrolyte, are not polarised and do not pollute the water column. Measurement is not affected by the speed of water flow, which makes it suitable for water measurement at various flow rates.