Swept-frequency dielectric moisture and density sensor
US6388453B1 · kind B1 · utility
Inventor
Key dates
| Filing date | Jan 25, 1999 |
| Grant date | May 14, 2002 |
| Priority date | — |
| Expiry date | Jan 25, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N33/10
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.