Liquid capacitance pressure transducer technique
US4425799A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 3, 1982 |
| Grant date | Jan 17, 1984 |
| Priority date | — |
| Expiry date | Jun 3, 2002 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/43
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A pressure transducer for measuring the difference in pressures between two liquids, includes two very closely spaced plates, at least one of which is a diaphragm, and opposed conductive coatings on these two closely spaced plates. The space between the two plates is evacuated, and a low viscosity silicon oil is drawn in through a conduit to completely fill the space between the two plates. The conduit leading to the space between the plates is filled up to a certain point with the low viscosity fluid, and a thin membrane or bellows tightly seals this conduit. One of the two liquids, the pressure of which is to be measured, is channelled to the outer side of the membrane or bellows; and the other of the two liquids is conducted to the outer surface of the diaphragm of the pressure transducer. Two concentric capacitors are formed by the opposed conductive coatings, with an inner variable capacitor having substantial changes as the diaphragm flexes, and the outer reference capacitor having very little change; but both of the capacitors being separated by the same dielectric liquid.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.