Non-contact measurement of water surface level from phase values of inductive measurements

Measurement of water surface level is important in many applications, including geophysics, ocean engineering, and various industrial processes. This paper describes a method for level measurement from phase values of inductive measurements. A modular inductive measurement system is developed based on a NI-PXI instrument. A linear array of inductive sensors is designed to investigate the sensitive range for different coil pair combinations. It is found that the phase values of inductive measurements are related to water surface level and the effects of conductivity can be eliminated. Finite Elements (FE) simulations and experimental results have confirmed the system performance and the validity of the proposed method.