Measuring and testing – Vibration – Resonance – frequency – or amplitude study
Reexamination Certificate
2006-12-12
2006-12-12
Williams, Hezron (Department: 2856)
Measuring and testing
Vibration
Resonance, frequency, or amplitude study
C073S023200, C073S024010, C073S024060
Reexamination Certificate
active
07146857
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, 11may 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 at a frequency determined by the resonance frequency, a repetitive frequency modulation is being generated by which a quantity representing the quality factor of the resonator (1, 11) is being generated in real time. Furthermore, means (7) for compensation of temperature or pressure dependence of the resonance frequency or quality factor are included. By an arithmetic-logical unit, e g a microprocessor (9, 17), measured values related to air quality, e g carbon dioxide concentration, relative humidity and temperature are being made available.
REFERENCES:
patent: 5695925 (1997-12-01), Ebersole et al.
patent: 5756279 (1998-05-01), Ebersole et al.
patent: 5768937 (1998-06-01), Wajid et al.
patent: 6247354 (2001-06-01), Vig et al.
patent: 2004/0129056 (2004-07-01), Hok et al.
Strutt et al., “Theory of Sound”, vol. 2, 2nd Ed. 1896, paperback version, Dover Books, NY, 1945, pp. 18-31.
Morse, “Thermal Physics”, WA Benjamin, NY 1969, 2nd Ed., pp. 206-209.
Doebelin, “Measurement Systems: Application and Design”, McGraw-Hill, NY pp. 126-137.
Beranek, “Acoustics”, McGraw-Hill, NY 1954, pp. 68-69, 136-139.
Frank Rodney
Hok Instrument AB
Merchant & Gould P.C.
Williams Hezron
LandOfFree
Real time analysis for gas mixtures does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Real time analysis for gas mixtures, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Real time analysis for gas mixtures will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3668872