SU529396A1 - Method for non-dispersive spectral analysis of gases - Google Patents

Description

one

The invention relates to spectral non-dispersive gas analysis methods and can be used to analyze single-element gases.

The emission method of analyzing single-element gases is well known, which is a very complex multistage process, requiring a considerable amount of time for its preparation and conduct 1. In addition, this method is not universal and consists of a variety of particular techniques, which vary depending on the composition of the analyzed mixture and the range of concentrations analyzed.

The closest technical solution is a method of non-dispersive spectral analysis of gases, based on the use of an optical-acoustic effect.

This method consists in the fact that a modulated radiation flux is passed through the analyzed binary mixture with the test gas and the concentration of the test gas is determined by the degree of absorption of the mixture through the optical flow by the optics-acoustic receiver.

The disadvantage of this method is low sensitivity in the analysis of oxygen and nitrogen

due to the insufficient intensity of the absorption bands in the transmission region of existing optical materials and the impossibility of analyzing inert gases and hydrogen due to the fact that the absorption bands (lines) of inert gases and hydrogen lie in the deep vacuum ultraviolet.

The aim of the invention is to provide the ability to perform an inert gas analysis.

This is achieved by the fact that the analyzed gas is excited, for example, by a high-frequency electromagnetic field in the cell with the test mixture and in the receiving cell of the optical-acoustic radiation receiver simultaneously and according to the degree of absorption of the selective radiation by the latter, the concentration of the analyzed gas in it.

The drawing shows a device that implements the proposed method.

Claims (1)

The device consists of a body 1 made of an optically transparent material, for example quartz. Inside the housing 1 there is a working chamber 2 with the analyzed mixture, an opto-acoustic receiver consisting of a beam-receiving volume 3 with the test gas, a membrane 4 and a fixed electrode 5 forming a condenser microphone, and a self-membrane volume 6. The optical-acoustic receiver is connected to the measuring unit 7, and the housing is installed between the electrodes 8 and 9, connected to the high-frequency electromagnetic generator 10. The cylindrical surfaces of the chamber 2 and the receiving volume 3 have reflecting in a given spectral region covered . The analyzed mixture and the gas under investigation, respectively, in chamber 2 and radial-receiving volume 3 at low pressure, are excited by means of generator 10. Since the lifetime and deposition of excited atoms is Š Ws, then by means of the same generator 10 electrical modulation of the radiation entering the radiation volume 3 from camera 2 with a frequency of, as a rule, 5-6 Hz. The modulated radiation from chamber 2 causes pressure pulsation in the beam-receiving volume 3, which is recorded with a condenser microphone and measuring unit 7. Formula of the Invention A method for non-dispersive spectral analysis of gases based on the use of an optical-acoustic effect, characterized in that possibilities of analyzing inert gases, the analyzed gas is excited, for example, by a high-frequency electromagnetic field in a cuvette with the test mixture and in a receiving chamber opt co-acoustic radiation receiver simultaneously and the degree of absorption of the last selective radiation mixture judged concentration of the sample gas therein. Sources of information taken into account in the examination: 1. Collection of automatic gas analyzers, M., 1961 p. 117-192, 292-298 P /  / J //, / x - y- - /.  /. v-. .u l / y. T five 8 1 / f / f x f  f × ff - /. IT