The impact of human activities has made marine ecological and environmental problems increasingly prominent, and long-term, automated, and continuous monitoring of seawater quality is of great significant. Dissolved oxygen in seawater refers to the oxygen dissolved in seawater, which plays an important role in the inventory and reproduction of marine organisms. Marine organisms also need to breathe and inhale oxygen, and dissolved oxygen in seawater is the source of oxygen for these organisms to breathe. Seawater lacking dissolved oxygen will cause marine organisms to lack oxygen and be unable to survive and reproduce. Therefore, dissolved oxygen is a conventional key parameter for seawater quality monitoring. The online dissolved oxygen sensor OPD700 developed and produced by Daruifuno is based on the principle of fluorescence quenching. The dissolved oxygen sensor has the advantages of high accuracy, good stability, and long-term online measurement. It has been widely used in seawate…