Method of identifying and detecting the concentrations of multiple species by means of a spectrophone

• US 20070256475A1
• Filed: 05/03/2007
• Published: 11/08/2007
• Est. Priority Date: 03/24/2004
• Status: Active Grant

• Current Assignee: Robert Crane
• Original Assignee: Robert Crane
• Inventors: Crane, Robert
• Granted Patent: US 7,647,815 B2
• Time in Patent Office: Days
• US Class Current: 73/24.10
• CPC Class Codes: G01N 2291/0215 Mixtures of three or more gases, e.g. air
• CPC Class Codes: G01N 29/036 by measuring frequency or resonance of acoustic waves
• CPC Class Codes: G01N 29/222 Constructional or flow details for analysing fluids optoacoustic fluid cells G01N29/2425
• CPC Class Codes: G01N 29/348 with frequency characteristics, e.g. single frequency signals, chirp signals measuring frequency of mechanical vibrations or acoustic waves in general G01H1/06, G01H3/04; measuring frequency or analysing frequency spectra G01R23/00
• CPC Class Codes: G01N 29/42 by frequency filtering or by tuning to resonant frequency

Abstract

A method of identifying and determining the concentrations of multiple species in a gas sample, includes providing a spectrophone assembly having a detector chamber, supplying the gas sample to the detector chamber and simultaneously passing a plurality of radiations of different wavelengths into the detector chamber to produce multiple acoustic resonances of different frequencies. Acoustic resonances in the detector chamber are simultaneously sensed to produce corresponding electrical signals, and the electrical signals are analysed to identify the species present in the gas sample and determine the concentration of each specie.

Claims

1. A method of identifying and determining the concentrations of multiple species in a gas sample, the method comprising:

providing a spectrophone assembly having a detector chamber,

supplying the gas sample to the detector chamber,

simultaneously passing a plurality of radiations of different wavelengths into the detector chamber to produce multiple acoustic resonances of different frequencies, said acoustic resonances being defined by internal geometry of the detector chamber,

simultaneously sensing acoustic resonances in the detector chamber and producing corresponding electrical signals, and

analyzing said electrical signals to identify the species present in the gas sample and determine the concentration of each specie.

2. A method according to claim 1 wherein the acoustic resonances are sensed by at least one microphone.

3. A method according to claim 1 including providing a plurality of detector chambers each with a single or multiple acoustic resonant mode.

4. A method according to claim 1 wherein the radiation is modulated in amplitude, frequency or phase or by utilizing the Stark effect to modulate the frequency of specie absorption with respect to the frequency or wavelength of the radiation passed into the chamber.