Abstract: A method for identification and partial-pressure determination of two gases in an unknown anesthesia gas mixture comprising n possible gases by measuring the infrared optical radiation, transmitted through the gas mixture, that passes through m filters having different transmission wavelength ranges, in which n is a number greater than 2 and m is a number less than n. The method evaluates the exit intensities, measured after passage through the filters, of the infrared optical radiation transmitted through the unknown gas mixture in such a way that with three filters, for instance, two gases in an unknown gas mixture comprising five possible gases can be identified, and their partial pressures can be determined. By dividing the partial pressures by the total pressure, it is optionally also possible to determine the concentration of the gases.

Abstract: The invention relates to a method for identification and partial-pressure determination of two gases in an unknown anesthesia gas mixture comprising n possible gases by measuring the infrared optical radiation, transmitted through the gas mixture, that passes through m filters having different transmission wavelength ranges, in which n is a number greater than 2 and m is a number less than n. A disadvantage of the method known until now is that for the identification and partial-pressure determination, at least as many filters as there are possible gases in the unknown gas mixture are always required. The method of the invention evaluates the exit intensities, measured after passage through the filters, of the infrared optical radiation transmitted through the unknown gas mixture in such a way that with three filters, for instance, two gases in an unknown gas mixture comprising five possible gases can be identified, and their partial pressures can be determined.

Abstract: An optical gas analyzer for measuring the percentage of components in a gas phase by IR absorption, containing a power source, a measuring path containing the gas sample, a photoelectric receiver with an evaluation circuit arranged downstream of it, which receiver detects the IR radiation from the measuring path, and a plurality of filters, which can be introduced one after another into the beam path at a predetermined filter change frequency f, wherein measured signals belonging to the filters are sent by the receiver due to the radiation extinction in the measuring path, is to be improved such that different components in the gas sample can be detected in a simple manner and at good selectivity.