Multiple frequency grain moisture sensor for combines
US6686749B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 25, 2001 |
| Grant date | Feb 3, 2004 |
| Priority date | — |
| Expiry date | Jan 4, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N33/10
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A grain moisture sensor is disclosed having a sensor cell that includes a driven plate, a sense plate proximate to and substantially parallel with the driven plate for capacitive measurement across a spacing between the driven plate and the sense plate, and a fill plate adjacent the sense plate and substantially parallel with the driven plate for sensing whether the spacing is filled with grain. Optionally, the sensor cell includes a guard proximate to the parallel to the sense plate such that the sense plate is between the driven plate and the guard. The grain moisture sensor provides for measuring real and imaginary components of an excitation voltage applied to the driven plate, measuring real and imaginary components of a sense current sensed at the sense plate, calculating a complex admittance of the cell, calculating a complex admittance of a reference admittance, and calculating a grain complex permittivity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.