[Measurement Principle]: Fluorescence measurement. Blue light is emitted to the fluorescent layer, and the fluorescent substance emits red light after being excited. The time it takes for oxygen and the fluorescent substance to return to the ground state is inversely proportional, which is used to measure dissolved oxygen. The value is stable and reliable. [Product Features] ◆ Optical dissolved oxygen measurement, no consumables, no need to replace electrolyte, easy maintenance. ◆ The body material is made of 304 stainless steel and POM plastic steel, which is corrosion-resistant. ◆ Equipped with automatic temperature compensation. [Applicable Places] Wastewater, recycled water, aquaculture, industrial water.