Simultaneous Non-contact Measurement of Water Level and Conductivity

Measurement of water level and conductivity is important in many applications, including geophysics, ocean engineering, and the oil industry, one example being gas/oil/water separation. Non-contact measurement is ideal for those applications. Capacitance, radar, ultrasonic and laser techniques have been used in measuring level, but simultaneous measurement of level and conductivity has not been reported. In this paper, we developed a novel inductive sensor, which uses two coils of different size to infer conductivity and level simultaneously based on a simplified model deduced from an analytical solution. The simplified model is verified with both simulation and experimental data. The experimental results have shown that measurement accuracy for both level and conductivity are within 3%