Design and implementation of ultrasonic self-oscillating and optical meters of media parameters

The aim of the research is to improve the technical parameters of ultrasonic meters by using the phenomenon of resonance and standing wave. The basis of the resonance method is the using standing acoustic waves arising in the medium due to the interference of the incident and reflected acoustic waves. The paper proposes a mathematical model of the ultrasonic resonance method for measuring parameters of liquid and gaseous media, which can be used for measuring control of parameters such as density, temperature, thickness, flow velocity, and others. To test the adequacy of the proposed model of ultrasonic wave propagation, its computer simulation and experimental studies were carried out. The air was chosen as the test medium (temperature 20° С, velocity 343m/s, atmospheric pressure 1atm). The time diagrams of the signal at the receiver for a distance of 34.3mm, when the resonance condition was satisfied, and for a distance of 34.73mm, when the ant resonance condition was satisfied, were modeled according to the proposed mathematical model. The dependence of the amplitude of the signal at the receiver is given for signal frequencies of 170–20kHz with a transmitter-to-receiver distance of 35.85mm and a sound speed of 340.8m/s. The simulation results confirm the adequacy of the purposed mathematical model. This allows proposing a new class of self-oscillating ultrasonic methods for measuring and control of medium parameters. The block diagram and the principle of operation of the auto-oscillating ultrasound meters for measuring the thickness, and gas temperature of test objects are described.