The invention discloses a
liquid viscosity measuring method based on a phase-locked loop
algorithm. Liquid flows in the guided
wave resonance element, the excitation and receiving coil is arranged on the surface of the guided
wave resonance element in an attached mode, a permanent
magnet is arranged beside the excitation and receiving coil, the
temperature control module is connected with the guided
wave resonance element, and the current sampling
resistor is connected with the excitation and receiving coil in series. Ultrasonic guided-wave vibration is generated in a guided-wave resonant element through an exciting coil,
voltage and current response signals of the resonant element are synchronously acquired by using a dual-channel synchronous sampling module, an impedance real part of the resonant element is accurately extracted according to the response signals, and accurate measurement of the
liquid viscosity is realized by combining an established impedance-
viscosity relation model. According to the invention, not only are the limitations of complex equipment, high cost and high requirement on
sample volume of the traditional
viscosity measurement method overcome, but also the problems of poor measurement stability, complex device manufacturing and difficulty in realizing online real-time monitoring under the working condition of strong
noise or high damping in the existing method are solved.