Single coil conductance measuring apparatus
US6359449B1 · kind B1 · utility
8Cited by
26References
12Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jun 29, 1999 |
| Grant date | Mar 19, 2002 |
| Priority date | — |
| Expiry date | Jun 29, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R27/08
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A conductance sensor uses a high impedance feedback oscillator to drive a single coil at the natural resonant frequency of the coil coupled to a measured material. The amplitude of the driving signal is also feedback controlled. The error signal of the amplitude control yields a measurement of resistance of the measured material. The combination of frequency adjustment and amplitude control eliminates non-resistance impedance effects and amplitude-dependent effects allowing high precision, high sensitivity measurement.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.