Device for measuring gas density
US5421190A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 4, 1993 |
| Grant date | Jun 6, 1995 |
| Priority date | — |
| Expiry date | Jun 4, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2291/0256
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The device serves to measure the density of a gas, in particular of the insulating gas of a gas-insulated electrical installation. It contains two resonators (11, 12) each comprising a piezoelectric crystal (14, 15) and each comprising two electrodes applied to the crystal. A first (11) of the two resonators (11, 12) is mounted in a first chamber (5) containing the gas to be measured, whereas a second (12) is mounted in a second chamber (6) sealed with respect to the gas. Despite small dimensions and despite simple and robust construction, this device is intended to have a high measurement precision over a long period of time. This is achieved by drawing the two resonators (11, 12) from a multiplicity of similar resonators manufactured by mass production and not subjected to a frequency alignment. The first resonator (11) is unaltered with respect to the manufacture in mass production. The second resonator (12) is likewise unaltered with respect to the manufacture in mass production and, under vacuum and with equality of temperature, it has the same resonance frequency as the first resonator (11) within a specified frequency tolerance. The second resonator (12) may, however, also b…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.