Planar capacitive transducer
US6842018B2 · kind B2 · utility
Inventor
Key dates
| Filing date | Apr 30, 2003 |
| Grant date | Jan 11, 2005 |
| Priority date | — |
| Expiry date | May 8, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D5/2405
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A transducer comprising at least one planar capacitor with a thin coverlayer of material selected to maximize electric field coupling between cooperating capacitor electrodes within a region external to a principal surface of the coverlayer. Preferred coverlayer materials have low values of moisture absorption, surface free energy, permittivity, dielectric dissipation, and electrical conductance. According to one embodiment of the invention, a driven shield further enhances electric field coupling over and in a region external to the principal surface. The transducer also can promote a physical change in specific adsorbates and materials and simultaneously detect and measure an effect of the induced change. Applications for the transducer of the invention include the measurement of the moisture content of grain and bulk stored commodities, humidity, a dew point temperature, the onset of condensation and rates of adsorption and desorption.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.