Julie D Whitney

US Patent:

54536200, Sep 26, 1995

Filed:

Aug 12, 1994

Appl. No.:

8/289809

Inventors:

Mark V. Wadsworth - Richardson TX
Julie G. Whitney - Georgetown KY
William L. McCardel - Plano TX

Assignee:

Texas Instruments Incorporated - Dallas TX

International Classification:

G01N 2161

US Classification:

250343

Abstract:

A nondispersive infrared gas analyzer 10 for indicating the concentration of a selected gas uses a source of radiation 12 to supply radiation to a gas sample chamber 14. The gas chamber 14 functions as an optical channel for transmitting radiation from the source of radiation 12 to both a gas sensing detector 22 and reference detector 24. An inner surface 36 of the gas chamber 14 is an optical reflective surface for the chamber and has a constantly changing irregular profile to greatly enhance optical scattering of the radiation falling on it to provide an uniform disperse radiation output to the detectors 22, 24. Additionally, the source of radiation 12 is chosen to provide radiation which is defocused to further help in attaining homogenous radiation output from the gas sample chamber 14 to the detectors 22, 24.