Real time analysis for gas mixtures
US7146857B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 16, 2004 |
| Grant date | Dec 12, 2006 |
| Priority date | — |
| Expiry date | Jan 11, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2291/101
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The invention is concerned with a method and apparatus for real time analysis of gas mixtures, e g determination of air quality, including at least one resonator (1, 11), means for gas transportation to and from the resonator (1, 11), e g by diffusion or transit flow via openings (5) means for activation (2) and detection (3) of an acoustic signal within the resonator (1, 11), at least one means (7) for measurement of the temperature within the resonator (1, 11), and at least one means (4) for the determination of both the resonance frequency and the quality factor of the resonator (1,11) in real time. These entities are related to the average molecular mass and viscosity or thermal conductivity, respectively, of the gas mixture. The resonator (1, 11 may include a compliant element, e g a constricted volume (6) and an inertial element, e g ist opening (5) or may support standing acoustic waves, in which the sound wavelength is related to a physical dimension of the resonator (1, 11). The determination of resonance frequency and quality factor is preferably based on phase detection within a phase locked loop and is thereby independent of magnitude. In addition to self oscillations a…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.