Absolute capacitance manometers
US4785669A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 18, 1987 |
| Grant date | Nov 22, 1988 |
| Priority date | — |
| Expiry date | May 18, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01L9/0072
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A single fluid-pressure transducer unit, of the type in which sensed electrical capacitance is varied in accordance with electrode deflections induced by pressure changes, is rendered capable of characterizing a wide range of pressures extending from near-vacuum to atmospheric levels, with the aid of a distinctive composite-electrode capsule which interacts uniquely with a conventional type of sheet-metal diaphragm. While sensing relatively low pressures, the exhibited capacitance of the transducer is essentially that appearing between the diaphragm and a nearby electrode carried by the capsule, but, at or near atmospheric pressure, the diaphragm physically engages and deflects that electrode, which is elastically deformable, causing it to vary a further capacitance appearing between that deformable electrode and a companion stationary electrode which is also part of the capsule.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.