The importance of monitoring seawater salinity lies in its impact on marine ecosystems. Changes in seawater salinity can affect the growth and reproduction of marine organisms, as well as the chemical balance of the marine environment. For example, high-salinity seawater may kill marine life, while low-salinity seawater may cause marine life to migrate or die. Usually, for the mariculture industry, it is necessary to monitor the dissolved oxygen value and salinity value of the water to allow fish to grow better. The OPD700 dissolved oxygen sensor and DEC350 salinity sensor of the Daruifuno brand are cost-effective sensors customized for the aquaculture industry. They are made of titanium alloy shells and can be used in both fresh water and sea water. They have long service life, accurate measurement, and require less maintenance. The advantage of four-electrode salinity sensor is that they have higher accuracy and stability. Traditional two-electrode…