Patent ID: 7183552

Claim:
A system adapted to analyze a concentration of a selected gas in a gas sample, the system comprising: (a) a gas analyzer comprising: (1) a gas analyzer housing, (2) a receptacle defined in the gas analyzer housing, (3) a source disposed in the gas analyzer housing and 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, and (4) an infrared radiation detector disposed in the gas analyzer housing 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 (b) a sample cell adapted to be disposed between the source and infrared radiation detector, wherein the sample cell includes: (1) a sample cell housing adapted to be selectively disposed in the receptacle, (2) a gas inlet disposed at a first end portion of the sample cell housing and on a first side of the sample cell, (3) a gas outlet disposed at a second end portion of the housing generally opposite the first end portion and on a second side of the sample cell generally opposite the first side of the sample cell, and (4) a gas flow passage defined in the sample cell through at least a portion of the sample cell housing between the gas inlet and the gas outlet, wherein the gas flow passage is generally parallel to the optical path between the source and the detector such that the gas flow passage defines a sample chamber, wherein a length of the gas flow passage defining the sample chamber is greater than a width of the gas flow passage, and wherein the gas inlet, the gas outlet, and the gas flow passage are disposed in a “Z” configuration in which at least one angle in the “Z” configuration through which gas passes is less than 90°, and wherein at least a portion of a wall defining the gas flow passage 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.