×

Optical path switching based differential absorption radiometry for substance detection

  • US 20040156050A1
  • Filed: 06/19/2003
  • Published: 08/12/2004
  • Est. Priority Date: 04/20/1998
  • Status: Active Grant
First Claim
Patent Images

1. A system for detecting a substance, comprising:

  • means for receiving radiation passing along a sample path of interest;

    means for dividing said radiation into a time series of alternating first polarized components and second polarized components orthogonal to said first polarized components;

    means for routing said first polarized components along a first optical path and said second polarized components along a second optical path;

    gasless means for passing all wavelengths of said first polarized components except at least a first wavelength band wherein first filtered radiation excluding said at least first wavelength band is generated;

    means for filtering said second polarized components to isolate at least a second wavelength band wherein second filtered radiation is generated, wherein said first wavelength band and said second wavelength band are unique and wherein spectral absorption of a substance of interest is different at said first wavelength band as compared to said second wavelength band;

    means for combining said first filtered radiation and said second filtered radiation to form a combined beam of radiation; and

    means for monitoring magnitude of said combined beam alternately at said first wavelength band and said second wavelength band as an indication of the concentration of said substance in said sample path.

View all claims
  • 0 Assignments
Timeline View
Assignment View
    ×
    ×