Abstract: A non-dispersive infrared analyzer for determining the concentration of two components of a sample fluid. A zero fluid and a sample fluid are alternately supplied to two cells. Two pneumatic detectors are respectively optically arranged in series with two light sources such that the two cells are respectively sandwiched between the two light sources and the two detectors. At least one filter whose passband corresponds to the absorbtion bands of one of the two components of the sample fluid is located directly adjacent to and optically in series with at least one of the two cells.

Abstract: An infrared radiation gas analyzer for determining the concentration of an ingredient in a sample gas has a sample gas container for containing a sample gas at a temperature at which the ingredient the concentration of which is to be determined will emit infrared radiation in a range characteristic of the ingredient and a window for allowing the infrared radiation to escape from the container. An optical chopper is positioned outside the container for interrupting the radiation escaping from the container. A filter is positioned in the path of the radiation escaping from the container and transmits only radiation in the range. An infrared radiation detector is positioned for receiving the radiation passed by the filter and emitting a signal representative of the radiation received by the detector and which is representative of the concentration of the ingredient the concentration of which is to be determined in the sample gas.

Abstract: A fluorescent gas analyzer for analyzing gases by the fluorescence method. A flashtube which is operated in its pulse mode is used as a light source. First and second optical detectors respectively detect light of a first and second wavelength range, the light of the first wavelength range being emitted by the light source and the light of the second wavelength range being emitted from a gas sample irradiated by the light source. A pair of integrators respectively integrate the outputs of the first and second detectors. Processing means, including sample and hold circuits and a synchronous detector, are used to further process the signals so that the system output is independent of deterioration of the light source and fluctuations in the strength of the light source output and independent of stray capacitance effects.

Abstract: A gas analyzer of the fluid modulation type includes at least one cell, structure for alternately introducing a sample gas to be analyzed and a reference gas into the cell, a detector for analyzing a property of the sample gas, and an arrangement for alternately discharging the sample gas and the reference gas from the cell. A critical flow device is located in the discharging arrangement. A pump is located in the discharging arrangement and has a capacity for operating the critical flow device under conditions of critical gas flow, thereby maintaining the gas passing through the critical flow device and the cell at a constant flow rate.

Abstract: An apparatus for analyzing carbon in metals, in which a metallic sample is burned in a current of oxygen in a combustion furnace and the concentration of carbon contained in the metallic sample is calculated from the total concentration of carbon monoxide and carbon dioxide in the gas generated in the combustion furnace, the concentration determined by means of a non-dispersive infrared analyzer. The non-dispersive infrared analyzer is provided with a detector which exhibits almost the same sensitivity to both carbon monoxide and carbon dioxide.

Abstract: A gas analyzer includes a first conduit for the supply of gas to be tested, a second conduit for the supply of a standard gas, first and second cells, a light source for directing light rays through the first and second cells, and a detector for receiving the light rays after passing through the cells. There is provided a gas flow change-over device connected to the first and second conduits for alternating at fixed intervals between a first gas supply arrangement wherein fixed amounts of gas to be tested and the standard gas are simultaneously supplied to the first and second cells, respectively, and a second gas supply arrangement wherein the fixed amounts of the gas to be tested and the standard gas are simultaneously supplied to the second and first cells, respectively.

Abstract: An opto-acoustic gas analyzer has a black body light source, a chopper in the path of the light emitted from the light source for intermittently intercepting the light from the light source, a positive interference filter in the path of the light for filtering out light other than the wavelengths of light absorbed by the gas being analyzed, and an opto-acoustic detector which receives the filtered light and through which the gas to be analyzed is passed. A pressure change detector provided is provided in the opto-acoustic detector for detecting pressure changes in the gas and producing an electric signal corresponding such changes.

Abstract: A combined motor and rotational cell for use in an apparatus for measuring components in a gas colorimeter, smoke meter, etc. by utilizing light absorption or fluorescence. The combined motor and rotational cell has a motor with a plurality of magnetic poles around the periphery of thereof, at least one diametrically extending partition wall extending across the hollow interior for defining at least two compartments in the rotor, and optically transparent windows on the outside of the motor closing the compartments. A plate-shaped chopper is provided on one side of the rotor having a plurality of apertures therein equidistantly spaced around the chopper. A casing surrounds the rotor and supports the rotor shaft in bearings and has a plurality of coils around the inside of the peripheral wall opposed to the magnetic poles on the rotor. Apertures are provided in the opposite end walls of the casing aligned with the compartments in the rotor for passing light through the casing and the rotor.

Abstract: A gas analyzer for measuring the concentration of a gaseous component in a test gas includes first and second separate cells adapted to alternately be filled with a test gas containing a gaseous component to be analyzed and a standard gas, light sources for directing rays of energy through the first and second cells and through the test gas and standard gas alternately contained therein, a detector positioned to receive the rays of energy after passage thereof through the first and second cells for detecting the concentration of the gaseous component within the test gas, and a changeover device connected to the first and second cells and adapted to be connected to sources of the test gas and the standard gas for alternately supplying the test gas and standard gas, at fixed intervals and in fixed amounts, into the first and second cells.

Abstract: An optical system for a spectroscopic analyzer. The system has a light source, a detector and a sample cell connected in a line, and in the sample cell or between the sample cell and one of the other elements is a light chopper device. The light chopper has a rotating element in the form of a disc-shaped member or members which periodically block light from the light source and pass light during the times it is not blocked. The rotating element is driven by a motor on the outside of the structure.