Method for high-accuracy non-contact capacitive displacement measurement of poorly connected targets
US6714023B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jan 29, 2003 |
| Grant date | Mar 30, 2004 |
| Priority date | — |
| Expiry date | Jan 29, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B7/002
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A non-contact capacitive displacement measurement gage that provides high accuracy displacement measurements of well-connected targets and poorly-connected targets. The capacitive displacement measurement gage includes a capacitive probe, first and second amplifiers, and a signal generator. The capacitive probe includes a sensor electrode, a guard electrode, and a compensating electrode. The signal generator provides a predetermined voltage signal directly to the sensor electrode, to the guard electrode through the first amplifier having unity gain, and to the compensating electrode through the second amplifier having a predetermined transfer function. The second amplifier assures that substantially zero current is driven into the target element by the probe during gage operation, thereby allowing highly accurate displacement measurements of target elements having unknown or poorly controlled impedance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.