Overview of product principles and classifications of dissolved oxygen meters
The Dissolved oxygen analyzer is based on the principle of electrochemistry, that is, an oxidation-reduction reaction will occur on two different metal sensors in the electrolyte solution containing oxygen, and the resulting diffusion current and oxygen concentration in the solution will An instrument for measuring the oxygen content in water based on the principle of a certain relationship. Some instruments also use the ji spectrum method in voltammetric measurement. After applying voltage to the working sensor in the solution, the current on the generated ji spectrum has a certain relationship with the concentration of the measured substance in the solution.
The dissolved oxygen sensor can be used to measure the dissolved oxygen content in the aqueous solution of the sample being tested on site or in the laboratory. Since dissolved oxygen is one of the main indicators of water quality, dissolved oxygen sensors can be widely used to measure dissolved oxygen content in various situations, especially in aquaculture water, photosynthesis and respiration, and on-site measurements. When evaluating the ability of streams and lakes to support biological survival, biochemical oxygen demand (BOD) testing is performed, measuring a sample aqueous solution containing organic matter that consumes oxygen as it becomes putrefactive, and determining the dissolved oxygen concentration and sample aqueous solution relationship between temperatures. Its measurement range: 0~5, 10, 20 mg/L, accuracy ±3%~±5%, and response time of about 30~120 s. There are two categories: online continuous monitoring and laboratory instruments.
A dissolved oxygen meter actually measures the amount of oxygen dissolved in an aqueous solution. Oxygen is dissolved in water through surrounding air, air movement, and photosynthesis. Dissolved oxygen sensors can be used to measure and monitor processes where oxygen levels can affect reaction rates, process efficiency, or the environment. The dissolved oxygen meter has the characteristics of easy installation, long calibration cycle (3 to 4 months), insensitivity to other substances, and the ability to monitor the use of the coating and internal electrolyte. Generally, the electrolyte and coating are replaced every one to three years.
Proper dissolved oxygen is essential for good water quality, and all life forms require oxygen. The natural stream water purification process requires the proper oxygen content to supply aerobic life forms. If the oxygen content in the water is lower than 5.0mg/L, it will be difficult for aquatic organisms to survive. The lower the concentration, the more difficult it is.
Dissolved oxygen meters are divided into several categories:
1. According to portability, it is divided into: portable dissolved oxygen meter, desktop dissolved oxygen meter and pen-type dissolved oxygen meter.
2. Divided according to use: laboratory dissolved oxygen meter, industrial online dissolved oxygen meter, etc.
3. According to the degree of accuracy, it is divided into: economical dissolved oxygen meter, intelligent dissolved oxygen meter, high-precision dissolved oxygen meter or divided into pointer type dissolved oxygen meter and digital display type dissolved oxygen meter.
4. Pen-type dissolved oxygen meters are generally made with a single range and a narrow measurement range, making them the most simple instruments.
