Contaminated sample gas analyzer and gas cell therefor
First Claim
1. A gas analyzer for performing gas analysis on a sample gas containing contaminants comprising:
- a source of radiant energy;
means for directing radiant energy through a sample gas, the radiant energy being directed along a sample gas optical path;
a gas cell comprising a sample gas cell having a sample enclosure for containing a sample gas volume, a sample window means for defining a portion of said sample gas optical path extending through said sample gas volume, an inlet for supplying sample gas to said sample gas volume and an outlet for exhausting sample gas from said sample gas volume, said sample cell being provided with a flow pattern extending transversely with respect to said sample gas optical path, said flow pattern being defined by an inlet manifold interconnecting said inlet and said sample gas volume, said inlet manifold being provided with a roughly constant cross-sectional area, and an outlet manifold extending from said sample gas volume to said outlet, said outlet manifold being provided with a roughly constant cross-sectional area, the cross-sectional area of said outlet manifold being greater than the cross-sectional area of said inlet manifold, the cross-sectional area of said inlet manifold being provided with a shape having roughly equilateral dimensions at said inlet to an elongate shape having a roughly uniform width at said sample volume, and the cross-sectional area of said outlet manifold being provided with an elongate shape having a roughly uniform width at said sample volume to a shape having roughly equilateral dimensions at said outlet, whereby turbulent flow and dead space in said sample gas volume is minimized;
a connector module for defining a channel for slidably receiving said gas cell and to provide for the periodic removal and replacement of said gas cell while maintaining the optical alignment of the gas analyzer;
detector means for receiving radiant energy from said sample gas optical path;
means for securing together in optical alignment said source, said means for directing radiant energy, said connector module and said detector; and
circuit means for analyzing the output of said detector and indicating the concentration of predetermined constituents of the sample gas.
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Accused Products
Abstract
A gas analyzer for performing gas analysis on a sample gas containing contaminants which normally interfere with the operation of the analyzer is disclosed comprising a source of radiant energy; means for directing radiant energy through a sample gas; a disposable gas cell; a detector for receiving radiant energy; and a circuit for analyzing the output of the detector and indicating the concentration of predetermined constituents in the sample gas. The gas cell comprises a disposable sample gas cell having a sample enclosure for containing a sample gas volume; sample windows defining a portion of a sample gas optical path extending from the source of radiant energy through the sample gas volume to the detector; an inlet for supplying sample gas to the sample gas volume and an outlet for exhausting sample gas from the sample gas volume. The disposable sample cell is provided with inlet and exhaust manifolds having cross-sectional areas that minimize dead space and insure laminar flow, minimizing stagnant areas. Specifically, the cross-sectional areas of the inlet and outlet manifolds are relatively constant, the cross-sectional area of the outlet being larger than the cross-sectional area of the inlet, and the inlet and outlet manifolds vary in cross-sectional shape from elongate shapes proximate the windows to a shape having roughly equilateral dimensions distal to the windows. The analyzer and the gas cell are provided with a number of inter-related features that make the analyzer self aligning and eliminates the necessity of recalibrating the analyzer each time a sample cell is replaced.
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Citations
34 Claims
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1. A gas analyzer for performing gas analysis on a sample gas containing contaminants comprising:
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a source of radiant energy; means for directing radiant energy through a sample gas, the radiant energy being directed along a sample gas optical path; a gas cell comprising a sample gas cell having a sample enclosure for containing a sample gas volume, a sample window means for defining a portion of said sample gas optical path extending through said sample gas volume, an inlet for supplying sample gas to said sample gas volume and an outlet for exhausting sample gas from said sample gas volume, said sample cell being provided with a flow pattern extending transversely with respect to said sample gas optical path, said flow pattern being defined by an inlet manifold interconnecting said inlet and said sample gas volume, said inlet manifold being provided with a roughly constant cross-sectional area, and an outlet manifold extending from said sample gas volume to said outlet, said outlet manifold being provided with a roughly constant cross-sectional area, the cross-sectional area of said outlet manifold being greater than the cross-sectional area of said inlet manifold, the cross-sectional area of said inlet manifold being provided with a shape having roughly equilateral dimensions at said inlet to an elongate shape having a roughly uniform width at said sample volume, and the cross-sectional area of said outlet manifold being provided with an elongate shape having a roughly uniform width at said sample volume to a shape having roughly equilateral dimensions at said outlet, whereby turbulent flow and dead space in said sample gas volume is minimized; a connector module for defining a channel for slidably receiving said gas cell and to provide for the periodic removal and replacement of said gas cell while maintaining the optical alignment of the gas analyzer; detector means for receiving radiant energy from said sample gas optical path; means for securing together in optical alignment said source, said means for directing radiant energy, said connector module and said detector; and circuit means for analyzing the output of said detector and indicating the concentration of predetermined constituents of the sample gas. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34)
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Specification