The working principle is based on radio frequency (RF) capacitor technology. A radio frequency is applied to the probe, and through continuous analysis, the
influence caused by the surrounding environment is determined. Because all materials have a dielectric constant and their conductivity is different from air,
the total impedance reflected by the slight capacitance shift when the probe is in contact with the material changes. Because the energized probe and the
container wall constitute the two plates of the capacitor, the insulator of the probe and the surrounding air become dielectric materials. When the air (its
dielectric constant is 1.0) is replaced by any other material (the dielectric constant>1), The capacitance effect is strengthened. Thereby changing the impedance
of the application. That is, the change of the capacitance value causes the change of the impedance. After this effect is measured by the circuit, it is compared
with the reference base established by the sensitivity setting (circuit).