Working principle and application of piezoelectric ultrasonic sensor

　　The working principle of piezoelectric ultrasonic sensor is mainly based on piezoelectric effect, which uses electrical components and other machinery to convert the pressure to be measured into electricity, and then performs relating measurement. Measuring precision instruments, such as many pressure transmitters and pressure sensors. Piezoelectric ultrasonic sensors cannot be used in static measurements. The reason is that the charge after being subjected to external force can be preserved only when the circuit has infinite input resistance. The following is provided, Let us briefly talk about the application of the working principle of piezoelectric ultrasonic sensors!

　　The actual arduino ultrasonic sensors can only be used in dynamic measurement. Its main piezoelectric materials are: dihydrogen phosphate, sodium potassium tartrate and quartz. The piezoelectric effect is found on quartz. When the stress changes, the electric field changes very little, and some other piezoelectric crystals will replace quartz. Potassium sodium tartrate, it has a large piezoelectric coefficient and piezoelectric sensitivity, but it can only be used indoors where the humidity and temperature are relatively low. phosphate is an artificial crystal, it can be used in high humidity and high temperature environment, so its application is very wide. With the development of technology, the piezoelectric effect has also been applied to polycrystals. For example: piezoelectric ceramics, niobate magnesium acid piezoelectric ceramics, niobate series piezoelectric ceramics and barium titanate piezoelectric ceramics are all included.

Piezoelectric effect ultrasonic sensor, it is electromechanical conversion and self-powered sensor. Its sensitive components are made of piezoelectric materials, and when the piezoelectric materials are subjected to external force, charges will be formed on its surface. The charges will pass through the charge amplifier, the amplification of the measuring circuit, and the impedance conversion. It is converted into a power output proportional to the external force received.

　　Technical parameters of piezoelectric ultrasonic sensors

　　 The piezoelectric constant ultrasonic proximity sensor is a parameter that measures the strength of the piezoelectric effect of a material, and it is directly related to the sensitivity of the piezoelectric output. The elastic constant and stiffness of piezoelectric materials determine the natural frequency and dynamic characteristics of piezoelectric devices. For a piezoelectric element of a certain shape and size, its inherent capacitance is related to the dielectric constant and the inherent capacitance affects the lower frequency limit of the piezoelectric ultrasonic sensor.

　　 In the piezoelectric effect, the mechanical coupling coefficient is equal to the square root of the ratio of the converted output energy (such as electrical energy) to the input energy (such as mechanical energy); it is an important parameter to measure the electromechanical energy conversion efficiency of piezoelectric materials.

　　The insulation resistance of piezoelectric materials ultrasonic proximity sensor will reduce charge leakage, thereby improving the low frequency characteristics of piezoelectric ultrasonic sensors. The temperature at which piezoelectric materials begin to lose their piezoelectric properties is called the curie point temperature.