Piezoelectric accelerometer working principle - Database & Sql Blog Articles

Photocoupler

Piezoelectric sensors generally consist of a housing and a spring, a mass, a piezoelectric element, and a fixedly mounted base housed within the housing. The piezoelectric element is generally composed of two piezoelectric sheets, and is plated with silver on both surfaces of the piezoelectric sheet, and the output end is led out by a silver layer or a metal block sandwiched between two silver layers, and the other lead at the output end. It is directly connected to the base of the sensor. A mass is placed on the piezoelectric sheet, and then the mass is preloaded with a hard spring, and then the entire assembly is placed in a metal housing of the base. In order to isolate the strain of the susceptor to the piezoelectric element, to avoid false signal output and increase the anti-interference ability of the sensor, the pedestal is generally thickened or made of a material with a relatively high rigidity.
In use, the sensor base and the test piece are rigidly fixed together. When the vibration is felt, since the stiffness of the spring is relatively large and the mass of the mass is relatively small, the inertia of the mass can be considered to be small. Therefore, it can be considered that the mass feels the same vibration as the sensor base and is subjected to an inertial force opposite to the acceleration direction, so that the mass has a force proportional to the acceleration acting on the piezoelectric sheet. Through the piezoelectric effect of the piezoelectric piece, a voltage varying with the vibration acceleration is generated on the surface of the piezoelectric piece. When the vibration frequency is much lower than the natural frequency of the sensor, the voltage outputted by the sensor is proportional to the force, that is, The acceleration experienced by the sensor is proportional. After inputting this voltage to the preamplifier, the acceleration can be measured with a common measuring instrument. If an appropriate integrating circuit is added to the amplifier, the vibration speed and displacement can be measured.