SU1013832A1 - Oxygen pickup - Google Patents

Description

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The invention relates to electrochemical gas analyzers for measuring the partial pressure of oxygen in gas-cutting mixtures where it is necessary to perform a fast and continuous monitoring of the gas composition. An oxygen sensor is known that contains a solid electrolyte from Zr02 measurement electrodes l3. The disadvantage of this sensor is that it only works at high temperatures from 700 to. The closest technical solution to the invention is an oxygen sensor containing an electrochemical cell with a solid electrolyte Based on lithium compounds and two electrodes 2j. A disadvantage of the known devices is that the sensor can be used at a temperature higher. In addition, vacuum electrolyte samples are used in this type of electrochemical cell. The sensitivity of the sensor is small, the change in the EMF does not exceed 6% when the oxygen partial pressure is changed by 2 orders of magnitude. The aim of the invention is to increase the measurement accuracy. This goal is achieved by the fact that in an oxygen sensor containing an electrochemical cell with a solid electrolyte based on a single lithium junction and two electrodes, the lithium compound taken in the following ratio, dB, is used as a solid electrolyte; Lithium oxide 1-10 Lithium sulfate + lithium carbonate is the Rest, and each of them take a quantity of not less than 10 weight. of the total. Solid electrolyte in this sensor. ensures stable operation

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2.10 sensors in the temperature range of 100 to, the range of measured pressures is up to 10 mm Hg. The drawing schematically shows an oxygen sensor. I The oxygen sensor consists of an electrochemical cell 1 with solid electrolyte 2 and two electrodes 3, a source t of an adjustable voltage, and a recording device for measuring small currents 5. The sensor operates as follows. Through the cell 1, to the electrodes 2. which is supplied with a small voltage, "4 No voltage of about 100-300mV, current flows due to the presence of oxygen and conductivity, and the following reactions occur on the electrodes: at the cathode: 0.5 09+ 2e - 2 on the anode:, 5 O Therefore, the magnitude of the current in the system depends on the partial pressure of oxygen. A change in the oxygen pressure in the system leads to a rapid and significant change in the magnitude of the current, which is recorded with an ammeter. In the interval of specified temperatures and pressures, the sensor almost instantaneously (in 1 s) reacts to a change in the oxygen partial pressure in the system. Receiving a main signal in the form of a current is convenient for measuring with great accuracy and makes it possible to measure Me only the equilibrium state of the system, but also the speed of reaching equilibrium. In tab. The data on tests of the oxygen sensor with the following e / h cells are presented: Pt / LijO Pt / Na20 5.5. Ag / NajO. 5.5 AljOj / Ag Ag / LijO. LijjCOj- LigSO / Ag

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Claims (1)

An OXYGEN SENSOR containing an electrochemical cell with a solid electrolyte based on lithium compounds and two electrodes, characterized in that, in order to increase the accuracy of measurements, lithium compounds taken in the following ratio, wt.%: Are used as a solid electrolyte: Lithium oxide 1-10 Lithium sulfate + lithium carbonate The rest, each of which is taken in an amount of at least. THAT weight of the total. <> I „SU η 1013832