A new type of four-electrode seawater conductivity sensor core is proposed based on quartz glass tube and metal titanium electrode. The material selection of the core and the separating electrode structure avoid polarization effect

and improve detection precision. Two kinds of detection systems are set up to measure conductivities of potassium chloride solutions in different experimental environments. The first system is designed to measure the conductivities of a variety of potassium chloride solutions at the same temperature

while the second is used to measure the conductivities of the same concentration of potassium chloride solution at different temperatures. Through several experiments and tests

the constant K of conductivity cell is determined to be2. 35 cm-1. Through

data analysis and calculation

the relational expression between conductivity and concentration at 25 ℃ is determined. And the temperature coefficients of three different concentrations of potassium chloride solution at 10

30 ℃ are given. The temperature compensation error is within 1%. The results show that the designed sensor in a seawater conductivity sensor with high detection precision and real-time detection function.