AMPEROMETRIC METHOD FOR MEASURING CONCENTRATION OF NITRIC OXIDE IN GAS MIXTURE WITH NITROGEN Russian patent published in 2021 - IPC G01N27/12 

FIELD: chemical industry.

SUBSTANCE: invention is intended for measuring the content of nitric oxide (NO) in a gas mixture with nitrogen and can be used in the production of nitric acid and calibration gas mixtures. An amperometric method for measuring the concentration of nitric oxide in a gas mixture with nitrogen consists in an analyzed gas mixture flow in placing an electrochemical cell with a cavity formed by two gas-tightly interconnected disks of an oxygen-conducting solid electrolyte of the composition 0.9 ZrO₂ + 0.1 Y₂O₃, between which there is a capillary, a DC voltage within 0.5-1 V is applied to the electrodes located on opposite surfaces of one of the disks, with a positive pole connected to the outer electrode, whereby are pumping from the cavity of the cell oxygen produced by the decomposition of nitric oxide, when reaching the stationary state, when the amount of oxygen pumped out from the cavity of the cell will be equal to the amount of oxygen entering the cavity via the capillary in the composition of nitric oxide, measured flowing through the cell limiting current corresponding to the concentration of nitric oxide, which is in an analyzed gas mixture, and determine the concentration of nitric oxide in the formula:

where: X_(NO) is the mole fraction of nitric oxide in the analyzed gas mixture; I_L(NO) is the limiting current corresponding to the amount of pumped oxygen formed after the decomposition of nitric oxide in the analyzed gas mixture, mA; R is the gas constant, 8.314*10⁷ erg/mol ⋅K; T is the analysis temperature, K; L is the capillary length, m; F is the Faraday number, 96485 Kl/mol; D_(NO) is the diffusion coefficient of nitric oxide in the analyzed gas mixture, m²/s; S – the cross–sectional area of the capillary, m²; P – the total pressure of the analyzed gas mixture, Pa.

EFFECT: ability to simply, reliably and quickly measure the content of nitrogen oxide in a gas mixture with nitrogen.

1 cl, 3 dwg