Pressure transducer with an invariable reference capacitor
US4422125A · kind A · utility
68Cited by
3References
7Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | May 21, 1982 |
| Grant date | Dec 20, 1983 |
| Priority date | — |
| Expiry date | May 21, 2002 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01L9/0086
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A quartz capacitive pressure transducer including a sensing plate and a reference plate disposed on one quartz substrate which are opposed across a gap by a common plate on another quartz substrate to form capacitances. The substrates are maintained in their opposing relationship by an annular frit which seals a chamber between the substrates to a reference pressure. The reference plate is disposed in the area occupied by the frit annulus to provide a reference capacitance that has a zero pressure gradient.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.