Water Content Measurement Method Based on RF Dual-Parallel-Antenna Sensor

To address the challenge of measuring the water content of oil-water two-phase flow over the entire range, both cost-effectively and reliability, this study developed an RF sensor utilizing dual parallel antenna electrodes. The sensor configuration includes two parallel electrodes vertically inserted into the pipeline: one serving as the transmitting electrode for emitting excitation signals, and the other as the receiving electrode for detecting signals. The precise measurement of 0-100% water content in oil-water two-phase flow is achieved by analyzing the attenuation changes of electromagnetic waves passing through the oil-water mixture. The sensor's propagation parameters, specifically the S21 amplitude and phase, were simulated and analyzed using COMSOL Multiphysics software, and the simulation results were validated through dynamic experiments. The water content in the range of 0 similar to 30% is based on the normalized phase value at 0.58 GHz, and the water content in the range of 40 similar to 100% is based on the normalized relative frequency shift parameter of the resonance peak from 220 MHz to 420 MHz, so as to realize the prediction of the full-range water content model. The model exhibited an average absolute deviation of 1.16%, indicating the proposed sensor's feasibility for measuring water content.