Fluorescence dissolved oxygen analyzer (DO meter) is an instrument used to measure the dissolved oxygen content in water, based on the principle of fluorescence quenching. Its core advantages include no need for consumable components (such as electrolytes), fast response speed, low maintenance costs, and strong anti-interference ability, suitable for scenarios such as aquaculture, sewage treatment, and environmental monitoring. Compared with traditional membrane electrochemical sensors, fluorescence technology can reduce pollution and drift issues, providing more stable long-term data.
The fluorescence based dissolved oxygen analyzer is based on the quenching principle of specific substances on active fluorescence in physics. The light emitting diode (LED) inside the instrument emits blue light, which illuminates the fluorescent substance on the inner surface of the fluorescent cap. The fluorescent substance is excited and emits red light. Oxygen molecules in water will come into contact with excited fluorescent molecules and undergo energy transfer, causing the fluorescent molecules to be unable to release red light normally, resulting in fluorescence quenching. The higher the concentration of oxygen molecules, the more pronounced the attenuation amplitude and shorter the attenuation time of the fluorescence signal. The instrument calculates the concentration of oxygen molecules by detecting the phase difference between red and blue light and comparing it with internal calibration values. The dissolved oxygen value is then automatically compensated for by temperature and pressure.
Product Features
Maintenance free: No electrolyte is required, avoiding electrolyte consumption and leakage issues, and there is no need to frequently replace membranes, reducing cleaning frequency and low maintenance.
Strong anti-interference: does not consume oxygen, does not interfere with the original dissolved oxygen balance of the water, and is not affected by substances such as hydrogen sulfide, resulting in stable measurement results.
Fast response speed: The response time is usually ≤ 30 seconds, which can reflect the changes in dissolved oxygen in the water in a timely manner and meet the dynamic adjustment needs of aeration systems, etc.
High precision: The measurement accuracy can reach ± 0.1mg/L, with a resolution of 0.01mg/L, and can accurately measure dissolved oxygen concentration.
Easy integration: mostly digital sensors, using RS485 output, supporting MODBUS protocol, can be easily integrated into various water quality monitoring systems.
Daily cleaning: Depending on the water quality, the laboratory environment needs to be cleaned every 2 weeks, and sewage or industrial wastewater needs to be cleaned more frequently, even after each use. Use a soft bristled brush to remove sediment, dip a cotton ball in anhydrous ethanol to wipe the optical window, then rinse with distilled water and air dry.
Calibration and Storage: Regularly perform air calibration to ensure accurate measurements. When not in use for a long time, be sure to store it in a protective cover with a damp sponge to keep the sensor moist and avoid drying and damage.
Special attention: Anti freezing measures should be taken in winter to avoid probe freezing and damage. Operate gently to prevent the membrane cap from breaking. Avoid contact with strong acids, bases, organic solvents, and sharp objects.