| 摘要 |
A swept-frequency shunt-mode dielectric sensor system is used to measure complex impedance parameters such as capacitance and/or dielectric loss of an object or substance being sensed. A precision, digitally synthesized sinusoidal voltage waveform is applied to an amplifier that has a precise, consistent relationship between gain and sensed complex impedance. The amplifier output is the input to a phase-loced synchronous demodulator, which produces a signal related to capacitance and/or loss factor of the object or material sensed. This swept-frequency information is used by a microprocessor that can apply mathematical algorithms to the data to calculate bulk density simultaneously with moisture or other properties of the material.
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