Resonance-induced sensitivity enhancement method for conductivity sensors
US7629797B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 5, 2007 |
| Grant date | Dec 8, 2009 |
| Priority date | — |
| Expiry date | Jan 15, 2028 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R27/22
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Methods and systems for improving the sensitivity of a variety of conductivity sensing devices, in particular capacitively-coupled contactless conductivity detectors. A parallel inductor is added to the conductivity sensor. The sensor with the parallel inductor is operated at a resonant frequency of the equivalent circuit model. At the resonant frequency, parasitic capacitances that are either in series or in parallel with the conductance (and possibly a series resistance) is substantially removed from the equivalent circuit, leaving a purely resistive impedance. An appreciably higher sensor sensitivity results. Experimental verification shows that sensitivity improvements of the order of 10,000-fold are possible. Examples of detecting particulates with high precision by application of the apparatus and methods of operation are described.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.