A Seawater Conductivity Measurement Method Based on Magnetic Resonance Coupling

This paper proposes a magnetic resonance coupling seawater conductivity measurement method with a dual-coil structure. The passive transceiver coil is composed of two detection coils and capacitive elements placed in seawater. The seawater conductivity measurement is realized by analyzing the relationship between the transmission loss of the resonant magnetic field between the passive transceiver coils in the seawater and the seawater conductivity. In the article, the magnetic resonance coupling measurement method is established and analyzed, the circuit model of the magnetic resonance coupling measurement system transmitted in seawater is established, the experimental device is set up for laboratory testing, and the corresponding test situation is simulated by finite element electromagnetic modelling. The test and simulation results show that the measurement method is feasible; the system has the best performance at the resonant frequency, especially for low-conductivity conditions, and better sensitivity. In addition, the resonant frequency increases, and the conductivity resolution of the measurement system for seawater increases.