Piezoelectric accelerometer structure and working principle - News - Global IC Trade Starts Here.

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Piezoelectric accelerometer, also known as piezoelectric accelerometer. It works by the piezoelectric effect of piezoelectric material. The so-called piezoelectric effect refers to some dielectrics, when it is deformed by mechanical external force in a certain direction. Electrodeization occurs inside, resulting in equal-sized, opposite-symbol charges on the opposite surfaces of the dielectric. When the direction of the external force changes, the polarity of the charge is also proportional to the amount of charge that is proportional to the external force. When the external force is removed, the dielectric returns to the uncharged state. This phenomenon is called the positive piezoelectric effect. Conversely, when an electric field is applied in the polarization direction of the dielectric, it is deformed. This phenomenon is called back pressure. Electrical effect. Piezoelectric accelerometers work with positive piezoelectric effects.

A dielectric having a piezoelectric effect is called a piezoelectric material. In nature, there are many substances having a piezoelectric effect, but most of the common effects are very weak, and only a few such as quartz crystals and piezoelectric ceramics have strong piezoelectric effects. .

The structural type of the piezoelectric accelerometer has three types of compression type, shear type and bending type. Figure 11-5 shows the structure of the compression type accelerometer. The sensitive component is the piezoelectric crystal piece 4, and the crystal piece is pressed with a mass 3 Applying a preload to the mass with a stiffer spring 2 and smearing them in a metal casing 1 with a thick base 6 when the accelerometer is mounted on the body being tested When the plate is moved, the mass generates a force proportional to the vibration acceleration acting on the piezoelectric crystal piece. According to the positive piezoelectric effect, alternating electric materials are generated on the opposite surface of the crystal piece, and the total size and function are generated. The force is proportional, the mass of the mass is fixed, so the charge on the crystal piece is proportional to the acceleration of the pull.

Piezoelectric accelerometers have the advantages of small size, light weight, solid structure, high frequency bandwidth, high sensitivity and wide measuring range. Piezoelectric accelerometers have good stability and are often used as standard accelerometers in vibration metrology.