The online trace dissolved oxygen analyzer is mainly used for real-time monitoring of dissolved oxygen content in water bodies or solutions. It has the characteristics of high accuracy and wide measurement range, and is widely used in environmental protection, water treatment, chemical industry and other fields.
Online trace dissolved oxygen meters typically use sensor technology to measure based on electrochemical or optical principles
Electrochemical sensor: measures the concentration of oxygen through electrochemical reactions. Oxygen diffuses through the membrane to the cathode, undergoes a reduction reaction, and generates a weak current. The magnitude of the current is proportional to the concentration of dissolved oxygen in water. The instrument calculates the dissolved oxygen concentration value by sampling and converting the current signal. Some instruments also consider the effect of water temperature on oxygen solubility and automatically perform temperature compensation.
Optical sensor: Using the principle of fluorescence, the oxygen concentration is determined by measuring the quenching effect of oxygen on the fluorescence signal.
The online trace dissolved oxygen analyzer mainly adopts two measurement techniques, which are suitable for different precision requirements scenarios:
Membrane method (polarography): Oxygen molecules diffuse into the electrolyte through a semi permeable membrane (such as polytetrafluoroethylene membrane). Under the polarization voltage (0.6-0.8V) between the gold electrode (cathode) and the silver electrode (anode), oxygen molecules undergo a reduction reaction at the cathode to release electrons, and the anode accepts electrons to form an electric current. The current intensity is proportional to the concentration of dissolved oxygen, and the dissolved oxygen value is obtained by conversion. This method requires regular replacement of electrolyte and oxygen permeable membrane, and is suitable for low to medium precision micro measurement.
Fluorescence method: The built-in light source emits blue light to irradiate the fluorescent substance, and the excited fluorescent substance emits red light. Oxygen molecules will take away energy through quenching effect, resulting in the emission time and intensity of red light being inversely proportional to the oxygen concentration. The instrument calculates the dissolved oxygen concentration by measuring the phase difference between red light and reference light, combined with internal calibration values.
Product Features
High precision measurement: capable of accurately measuring trace amounts of dissolved oxygen concentration in water bodies with low error rates, meeting the requirements of high-precision monitoring.
Real time monitoring: capable of continuously and accurately measuring dissolved oxygen concentration in water bodies, providing real-time data, and supporting online continuous monitoring.
Data storage and analysis: Usually equipped with data storage functions, it can record long-term dissolved oxygen concentration data and be used for trend analysis and optimization operations.
Alarm function: When the dissolved oxygen concentration exceeds the preset range, it can automatically alarm and remind the user to take corresponding measures.
High protection level: The equipment has a high protection level, with a working temperature range of -25 to+55 ℃, and is suitable for various harsh environments.