Piezoelectric elements testing method

1, the resonance frequency fs series, parallel resonant frequencies of fp, equivalent resistance and a sound fs1 frequency R1 is three times, the sound fs3 frequency measurement, the common transmission circuit as follows:
Left Π network measurement sample on both ends of the signal amplitude small changes, the interference, but smaller network Π network for the constant pressure measurement must be for measuring R1 low resonant frequency fs series materials measurement accuracy, low and must satisfy the RI/RT1 p < 10, RT2 R1, Parallel resonant frequencies measured fp RT2 when the hundredth Ω 1K Ω 2K ~.
Right constant-current test network can measure R1 low resonant frequency fs series (maximum admittance resonant frequencies measured FM, when HHG for signal, so the distortion degree higher requirements. RT3 / R1 experiment.it RT3 100 Ω ~ 3K Ω hundredth 200.
Can the resonant frequency in tandem with high resistance box under the fs resistance of alternative sample equivalent resistance R1.

2 and free capacitance CT and dielectric loss Angle tangent delta (tg) can use directly read CT and electrical capacitance tg delta.
3 and longitudinal d33 constants of piezoelectric strain measurements:
Piezoelectric d33 constant strain can use transmission method for measuring the fs, fp and CT, use to calculate, also can use in direct measurement of static method, and general electric capacity on the sample, capacitor, longitudinal compression static electricity meter reading with samples of piezoelectric equation based on static voltage, the:

have

To meet the following conditions:
1, the electrical circuit boundary conditions, namely E constant,
2 and sample only along the polarization direction stress,
3, make stress and strain line relations,
4 and stress area and polarization same area.
A standard static d33 measuring instrument can also more accurate measurement d33.