Apparatus and method to identify and measure gas concentrations

Inventors

Uplinger, II, James Robert • NICHOL, ROBERT M • Keller, Walter John

Assignees

Nokomis Inc

Abstract

A method and apparatus is provided for the analysis of gaseous compounds, especially for determining the concentration of a gas or gases in a gas mixture by microwave spectroscopy. Microwave radiation is generated at one or more frequencies the gas is most responsive to, transmitted by antenna, passed through the gas under test, received by antenna, and the absorption and/or reflection of the microwave radiation is measured by means such as digitization and analysis using the FFT spectrum versus energy response generated, the response subsequently used to calculate the gas concentration.

Core Innovation

The invention provides a microwave/RF spectroscopy approach for non-contact gas concentration identification and quantification by passing a gas mixture through an electromagnetic field generated by a pair of antennas. The system measures one of an absorption amplitude, an emission amplitude, and a reflection amplitude of the gas mixture, or measures an electromagnetic energy difference between an emission spectrum transmitted from a transmit antenna and an emission spectrum absorbed or reflected by gaseous molecules. The measured values are converted to an absolute gas mixture concentration.

The converted absolute gas mixture concentration is compared against a stored value, and the gas mixture is analyzed based on a result of the comparison. In another configuration, the electromagnetic energy difference is converted into a digital signal, one of an absorption amplitude, an emission amplitude, a reflection amplitude, and any combinations thereof is measured in the digital signal, the measured amplitude is converted to an absolute concentration, and the absolute concentration is compared against a stored value.

The apparatus and handling configurations include a hollow enclosure and antenna arrangements that support measurement of microwave electromagnetic energy through the gas mixture while the gas mixture flows between a transmit antenna and a receive antenna. The hollow enclosure may be configured as a Faraday cage with the antennas encased therein, and the document also describes optional intake and evacuation members associated with the hollow enclosure. A control system digitizes the captured signals, processes the resulting spectrum or energy response, and performs comparison and analysis, including use with exhaled breath and medical-condition presence or absence.

Claims Coverage

The independent claims cover three method aspects: measuring absorption, emission, or reflection amplitudes and converting them to an absolute concentration for comparison-based analysis; conducting a controlled gas-flow experiment in a hollow enclosure, including evacuation and optionally Faraday shielding, to capture an electromagnetic energy difference and determine an absolute concentration for comparison; and determining concentration by transmitting and capturing an electromagnetic energy difference from absorption or reflection in a gas mixture with subsequent digital processing and analysis. Across these independent claims, at least seven main inventive features are recited in varying combinations.

Across the independent claims, the central claim coverage is directed to measuring absorption, emission, or reflection amplitudes or an electromagnetic energy difference produced by absorption or reflection of gaseous molecules, converting the resulting signal into absolute concentration via digital processing, and using that concentration for comparison-based analysis, including comparison against stored values, with independent claim variants covering antenna spacing, hollow-enclosure intake and evacuation, and optional Faraday cage encasing.

Stated Advantages

Documented Applications