Precise high resolution non-contact method to measure dielectric homogeneity
US5874832A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 20, 1996 |
| Grant date | Feb 23, 1999 |
| Priority date | — |
| Expiry date | Dec 20, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R27/2641
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An apparatus and method for measuring the dielectric constant or permittivity at a plurality of positions on a test specimen are provided. Accordingly, the present invention enables the spatial variance of the dielectric constant, i.e., the dielectric homogeneity, of the test specimen to be measured. In particular, high resolution dielectric homogeneity measurements are performed at low frequency (100 kHz to 10 MHz) using a specially designed guarded electrode assembly and a specially selected high permittivity matching liquid. The guarded electrode assembly comprises a guarded electrode surrounded by a guard electrode which is supported over a test specimen resting on a planar electrode. The test specimen and the planar electrode are immersed in a dielectric fluid. The guarded electrode as well as the guard electrode, which extends into the dielectric fluid, are translated across the test specimen while the capacitance between the guarded electrode and the planar electrode is measured. The present invention is designed so that the number of required measurements are reduced compared to other techniques for measuring permittivity. The present invention also overcomes problems assoc…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.