Optical system for a gas measurement system
First Claim
1. A system adapted to analyze a concentration of a selected gas in a gas sample, the system comprising:
- a source adapted to emit radiation of a specified intensity and wavelength along an optical path such that the radiation is absorbed by the selected gas in the gas sample being analyzed;
an infrared radiation detector disposed along the optical path in optical communication with the source and adapted to detect an intensity of the emitted radiation by the source after the radiation has passed through the gas sample; and
a sample cell adapted to be disposed between the source and infrared radiation detector, wherein the sample cell includes a gas flow passage defined that intersects the optical path, and wherein at least a portion of a wall defining the optical path includes an infrared reflective surface so as to direct rays of radiation from the source to the infrared radiation detector generally along the optical path.
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Accused Products
Abstract
An improved optical configuration for use in a gas monitoring system. The optical system uses a high numerical aperture lens that maximizes capture of relatively large angle rays, thereby increasing the measured signal at the infrared radiation detector. In one embodiment of the present invention, a half-ball-type lens is provided proximal to the infrared radiation source in the gas measurement system. To further increase the measured signal at the infrared radiation detector and allow more efficient capture of the larger angle rays, materials that are reflective in the infrared band of interest are used, so that the walls of the sample cell act as a hollow light pipe.
54 Citations
12 Claims
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1. A system adapted to analyze a concentration of a selected gas in a gas sample, the system comprising:
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a source adapted to emit radiation of a specified intensity and wavelength along an optical path such that the radiation is absorbed by the selected gas in the gas sample being analyzed;
an infrared radiation detector disposed along the optical path in optical communication with the source and adapted to detect an intensity of the emitted radiation by the source after the radiation has passed through the gas sample; and
a sample cell adapted to be disposed between the source and infrared radiation detector, wherein the sample cell includes a gas flow passage defined that intersects the optical path, and wherein at least a portion of a wall defining the optical path includes an infrared reflective surface so as to direct rays of radiation from the source to the infrared radiation detector generally along the optical path. - View Dependent Claims (2, 3, 4, 5)
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6. A system for analyzing the concentration of a selected gas in a gas sample, comprising:
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a source adapted to emit radiation of a specified intensity and wavelength such that the radiation is absorbed by the selected gas in the gas sample being analyzed;
a high numerical aperture lens disposed so as to receive radiation from the emitter and direct the emitted rays in a manner to be substantially parallel to each other; and
an infrared radiation detector in optical communication with the emitter and adapted to detect an intensity of the emitted radiation by the source after the radiation has passed through the gas sample. - View Dependent Claims (7, 8)
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9. A sample cell comprising:
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a sample cell body having a gas flow passage defined therethrough;
a sample cell chamber defined in the sample cell body, wherein the sample cell chamber defines a portion of the gas flow passage and at least a portion of an optical path, and wherein at least a portion of a wall of the sample cell chamber defining the optical path includes an infrared reflective material;
an optical aperture defined in a portion of the sample cell to allow radiation to pass through the sample cell chamber; and
a first window disposed over the first optical aperture.
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10. A method of analyzing a concentration of a selected gas in a gas sample comprising:
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providing a sample cell comprising a sample cell body having a gas flow passage defined therethrough, a sample cell chamber defined in the sample cell body such that the sample cell chamber defines a portion of the gas flow passage and at least a portion of an optical path, wherein at least a portion of a wall of the sample cell chamber defining the optical path includes an infrared reflective material, and wherein the sample cell includes an optical aperture defined in a portion of the sample cell;
emitting infrared radiation of a specified intensity and wavelength from a source through the aperture along the optical path;
absorbing a portion of the emitted radiation by the selected gas in the sample cell chamber; and
detecting an intensity of the emitted infrared radiation by an infrared radiation detector disposed along the optical path in optical communication with the source after the radiation has passed through the gas sample. - View Dependent Claims (11)
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12. A method of analyzing a concentration of a selected gas in a gas sample comprising:
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emitting infrared radiation of a specified intensity and wavelength from a source through the aperture along an optical path;
providing a high numerical aperture lens disposed along the optical path so as to receive radiation from the emitter;
passing the emitted radiation through the high numerical aperture lens;
passing the emitted radiation through a gas sample after having passed through the high numerical aperture lens;
absorbing a portion of the emitted radiation by the selected gas such a gas sample; and
detecting an intensity of the emitted radiation by an infrared radiation detector disposed along the optical path in optical communication with the source after the emitted radiation has passed through the gas sample.
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Specification