KNF-103B DO sensor uses self-developed fluorescent materials to nondestructively measure dissolved oxygen concentration in water. It has the advantages of no pollution, long service life, good stability and low maintenance difficulty. The unique optical detection mode of the measuring probe can effectively eliminate the interference of PH fluctuations, ammonia nitrogen and other chemicals or heavy metals in the water, so as to provide more stable and accurate measurement results over a longer period of time. Dissolved oxygen sensor is suitable for aquaculture (such as South American shrimp, eel, osmanthus fish, etc.), environmental protection water treatment and other water industry dissolved oxygen concentration measurement and control requirements.