PZP Vibratory Probe

The PZP utilizes piezoelectric technology to create a vibration and then constantly monitors the presence or absence of that vibration.


Two piezoelectric crystals are located in the base of the probe. A signal is applied to one crystal at the frequency corresponding to the probe’s selfresonance.

The electrical excitation causes physical deformation of the crystal resulting in probe vibration. With no material present, the vibration of the probe is felt by the second crystal. This vibration causes physical deformation of the second crystal which generates a voltage to be analyzed by the electronic circuitry. With material present around the probe, the vibration is dampened, thereby minimizing the voltage generated by the second crystal. The output voltage is analyzed by the circuitry and the relay status changes accordingly.