Piezoelectric pressure transmitter is mainly based on the piezoelectric effect, which uses electrical components and other machinery to convert the pressure to be measured into electricity, and then performs related measurement work.Piezoelectric transmitters cannot be used in static measurement, because the charge after being subjected to external force can only be preserved when the loop has an infinite input impedance.But that’s not actually the case.Therefore, piezoelectric transmitters can only be used in dynamic measurements.Its main piezoelectric materials are: ammonium dihydrogen phosphate, potassium sodium tartrate and quartz. The piezoelectric effect is found in quartz.
When the stress changes, the change in the electric field is very small, and some other piezoelectric crystals will replace the quartz.Potassium sodium tartrate, it has a large piezoelectric coefficient and piezoelectric sensitivity, but it can only be used in places where the indoor humidity and temperature are relatively low.Dihydrogen 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, magnesium niobate piezoelectric ceramics, niobate piezoelectric ceramics and barium titanate piezoelectric ceramics, etc. are included.
The transmitter based on the piezoelectric effect is an electromechanical conversion type and a self-generating type sensor.Its sensitive element is made of piezoelectric material, and when the piezoelectric material is subjected to external force, an electric charge will be formed on its surface,After the charge is amplified by the charge amplifier, the measuring circuit, and the impedance is transformed, it will be converted into a power output proportional to the external force received.It is used to measure force and non-electrical physical quantities that can be converted into forces, such as:acceleration and pressure.It has many advantages: light weight, reliable operation, simple structure, high signal-to-noise ratio, high sensitivity and signal bandwidth, etc.However, it also has some disadvantages: some voltage materials are not humid, so a series of moisture-proof measures need to be taken, and the response of the output current is relatively poor, then a charge amplifier or a high input impedance circuit should be used to make up for this shortcoming, Make the instrument work better.
Post time: Mar-27-2022