Abstract: A gas analyzer system for providing a spectroscopic analysis of the sample gas. This analysis is accomplished by first introducing the sample gas into the inlet of the system and transporting it to a spectral analyzer. The sample gas is then spectrally analyzed and the analyzer outputs a signal indicative of a radiation intensity spectrum associated with the analyzed sample gas. A processing unit uses the analyzer signal to detect the presence of one or more prescribed gases and to determine the concentration of each of the prescribed gases in the sample gas. Next, the reacting agent is supplied to the sample gas to convert one or more gases whose presence in the sample gas cannot be detected via spectral analysis due to the masking effects other gases present in the sample gas. The masked gases are converted to secondary gases at least one of which is readily detectable via spectral analysis.

Abstract: A filter probe for sampling components of a stack gas which includes means for extracting a flow sample of the stack gas, means for inertial filtering of the flowing stack gas sample extracted by the extracting means, means for collecting the flowing stack gas sample after filtering by the filtering means, means for conditioning the filtered and collected stack gas sample based on predetermined criteria such as cooling and drying, and means for flowing the filtered and collected stack gas sample from the collecting means to the extracting means so that a constant flow of the filtered stack gas sample is presented to the conditioning means to permit essentially instantaneous analysis of the stack gas sample.

Abstract: An optical fluid analyzer uses the extent of optical, preferably infrared absorption of a fluid to be analyzed to determine the concentration of a selected constituant of the fluid. A first detector detects light after absorption by the fluid at a wavelength at which the selected constituant has a characteristic absorption for conversion into an electrical signal indicating the concentration of the selected constituant and a background from absorption of other constituants of the fluid for a measurement processing channel. A second detector correspondingly converts light after absorption by the fluid, but at a different wavelength at which the absorption at least approximates the background absorption alone for a neutral processing channel.

Abstract: A gas sampling device has a gas-entry passage dimensioned to provide laminar flow to the gas and opening into a larger gas-receiving passage. A gas sampling tube is supported from the larger gas-receiving passage, extends only to the smaller gas-entry passage for sampling the entering gas, and is coaxially spaced from the walls of the gas-entry passage to sample the gas in the gas-entry passage without dilution from the gas-receiving passage or interference with the gas flow. The device is particularly useful for sampling small exhaled breath gas flow in combination with neonatal respiratory apparatus for sampling the breath of neonates.

Abstract: An optical gas-concentration analyzer which utilizes the infrared absorption principle has a sample chamber and reference chamber with infrared source and detector assemblies spaced at opposite ends of an in alignment with the chambers. An electronic processing system utilizes a spectral-absorption electrical signal from the detector assembly to derive the desired gas-concentration measurement for readout from a display device. Barometric correction means is provided to permit on site calibration by the user of the gas analyzer via an atmospheric pressure calibration indication obtained on the display device by switching the apparatus to a calibrating mode. Apparatus for compensating for broadening of the spectral line of a gas the concentration of which is to be measured by another gas in the sample and for the temperature of the sample gas is also provided.