Why should piezoelectric ceramic sheets be protected from moisture?
1. What are the specific values of elastic modulus, density and poisson's ratio of piezoelectric ceramics?
About piezoelectric ceramic chip, it is usually made of PZT - 4 Material poling pzt ceramics. Therefore, its elastic modulus is 7.65x100 and its density is 7.5 × 103. Poisson's ratio is 0.32. These are all things we have to know and master.
2.For piezoelectric ceramic sheets, if they are exposed to DC voltage, will there be electrostriction?
If piezoelectric ceramics are exposed to DC voltage, there will be no current flowing through them. Therefore, it is not electrostrictive. However, if it is in an alternating electric field or alternating voltage, there will be electrostriction, but only a small current will flow through it. This is because the input resistance of piezoelectric cylinder crystal transducer is very high, so it can be regarded as insulator. Therefore, only a small current will flow through it.
3.If the working point of piezoelectric ceramic transducer does not work at its resonant frequency, what will be the affected?
About ultrasonic piezoelectric cylinder transducer, if it has a natural resonance frequency. Therefore, if it does not work at this time, the sensitivity of the sensor will be reduced. If it is serious, it will also hinder the measurement work and make the sensor unable to work normally.
4. Why should piezoelectric ceramic crystal be moisture-proof?
This is because if energy harvesting plate piezoelectric plate is affected by humidity, they are prone to short circuit and other problems, thus is affecting the normal use of piezoelectric ceramics. It should be noted that it is greatly affected by environmental humidity. Therefore, piezoelectric ceramics should be affected by humidity, so as not to affect their usage.