Closed-Loop Resonant Density Sensor Design Using Electromagnetic Excitation and Magnetic Detection

With a hyperbolic U-tube as the resonant sensing element, the resonant density sensor adopts electromagnetic excitation and magnetoelectric detection for electromechanical transduction, enabling an integrated synergistic design. The resonance principle of the resonant density sensor and the electromechanical conversion method, using the electromagnetic induction principle, are analysed, and the theoretical model is investigated based on ANSYS Electronics 2022 and ANSYS Workbench 2022 R1 simulation software. In open-loop mode, the amplitude-frequency characteristics of the resonant network are measured, and the mechanical structure achieves a quality factor greater than 1000, as determined by the bandwidth method; In closed-loop mode, the measurement stability of the hyperbolic U-tube is periodically measured under various fluid loads, and the real-time ambient temperature is monitored. The sensitivity of the closed-loop system for density measurement is close to -0.1 Hz·kg^-1·m³, and the absolute error between the density correction value and the standard value is within ±1 kg/m³.