Capacitive vacuum measuring cell
US6591687B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 22, 1998 |
| Grant date | Jul 15, 2003 |
| Priority date | — |
| Expiry date | Dec 22, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49224
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A capacitive vacuum measuring cell includes first and second ceramic housing bodies (1, 4) joined by an edge seal (3). A thin ceramic membrane (2) is supported between first and second housing bodies (1, 4) by the edge seal (3) at a small distance from the first housing body (1) creating a reference vacuum chamber (25) therebetween. An electrically conductive material (7) coats opposing surfaces of the first housing body (1) and the membrane (2) to form a capacitor. A measurement vacuum chamber (26) is provided between the membrane (2) and the second housing body (4). A port (5) communicates with the second housing body (4) to connect the measurement vacuum chamber (26) of the measuring cell to the medium to be measured. The membrane (2) is made from an Al2O3 slurry that is sintered in a first heating step, cooled, and then reheated to smooth the membrane.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.