Abstract: A system and method for measuring a sludge moisture content by ultrasound are provided, which relate to the technical field of sludge detection. The system includes: a measuring container, configured to load sludge; a pulse signal generator, configured to generate a pulse signal; a self-transmitting self-receiving (STSR) transducer, disposed on an outer wall of the measuring container, and configured to transmit a first ultrasonic signal into the measuring container under an excitation of the pulse signal and receive a second ultrasonic signal reflected from an inner wall of the measuring container; and an upper computer, configured to build a first mathematical model among a reflection coefficient, sludge acoustic impedance, and wall acoustic impedance of the measuring container, and build a second mathematical model between the sludge acoustic impedance and the sludge moisture content.

Abstract: A system for measuring a rising velocity and a deformation of a bubble in a viscous fluid includes a sample cell configured to hold a viscous fluid, a variable-diameter syringe provided at a bottom of the sample cell and configured to generate a bubble in the viscous fluid, two ultrasonic transmitting and receiving transducers arranged at different heights of the sample cell and configured to transmit first ultrasonic signals to the viscous fluid and receive second ultrasonic signals reflected by the bubble, and a host computer configured to analyze time-domain information of the second ultrasonic signals received by the two ultrasonic transmitting and receiving transducers, calculate the rising velocity of the bubble, build a mathematical model about a bubble size and a reflected sound pressure, analyze frequency-domain information of the second ultrasonic signals received by the two ultrasonic transmitting and receiving transducers, and calculate the deformation of the bubble.

Abstract: A system for measuring a rising velocity and a deformation of a bubble in a viscous fluid includes a sample cell configured to hold a viscous fluid, a variable-diameter syringe provided at a bottom of the sample cell and configured to generate a bubble in the viscous fluid, two ultrasonic transmitting and receiving transducers arranged at different heights of the sample cell and configured to transmit first ultrasonic signals to the viscous fluid and receive second ultrasonic signals reflected by the bubble, and a host computer configured to analyze time-domain information of the second ultrasonic signals received by the two ultrasonic transmitting and receiving transducers, calculate the rising velocity of the bubble, build a mathematical model about a bubble size and a reflected sound pressure, analyze frequency-domain information of the second ultrasonic signals received by the two ultrasonic transmitting and receiving transducers, and calculate the deformation of the bubble.