Ultrasonic distance measurement transducer of piezo sensor

Ultrasound refers to sound waves with frequencies above 20 kHz and it is a kind of mechanical wave. Because it has good directionality and tolerance to the environment, piezo ring electric sensor is used in torque measurement technology. Ultrasonic distance measurement is a non-contact ranging technique. The main methods are pulse method, phase method and frequency conversion method. Ultrasonic distance measurement mainly uses the pulse method. The pulse method of piezo sound PZT materialsdirectly calculates the distance value by measuring the time for the carrier pulse signal to travel back and forth over the distance to be measured. Its formula is D = V t2D /2 where D is the distance value to be measured by electronic piezoceramic disc crystal ; V is the propagation speed of the carrier in the air; t2D is the carrier round-trip time. The accuracy of the pulse method ranging is affected by the accuracy of the piezo sphere transducer, and the accuracy of th  e time is affected by the oscillation frequency. If ultrasonic waves are used as carrier waves, and the required ranging accuracy ΔD ≤ 1 cm, then the required time measurement accuracy is Δt ≤ 5. 9 × 10- 5 s, that is, as long as the oscillation frequency reaches 1. 7× 104 Hz, it is very easy. Piezoelectric ultrasonic transducers are made using the piezoelectric effect of piezo transducer datesheet. The polarized piezoelectric material undergoes mechanical deformation under the applied electric field. This is called the inverse piezoelectric effect. Conversely, the mechanical deformation of the piezoelectric material also generates the voltage. This is called the positive piezoelectric effect. Using the inverse piezoelectric effect, high-frequency voltages piezo energy harvesting can be converted into high-frequency mechanical vibrations to generate ultrasonic waves; the positive ultrasonic vibrations can also be used to convert received ultrasonic vibrations into electrical signals. This is how the ultrasonic transducer works. Piezoelectric ultrasonic transducers can be seen as four-terminal networks with electrical and mechanical ends.