METHOD FOR PREPARING GAS MIXTURES FOR CALIBRATING GAS ANALYZERS Russian patent published in 2023 - IPC G01N1/38 G01N1/22 G01N35/10 

FIELD: engineering.

SUBSTANCE: methods for preparing gas mixtures for calibrating gas analyzers. Invention can find application when testing products for leaks using test gases, in particular when testing products of rocket and space technology, as well as in such areas as gas, nuclear, aviation engineering, with increased requirements for tightness, durability and reliability of products, for example, sealed compartments and pneumohydraulic systems of spacecraft. The method for preparing gas mixtures for calibrating gas analyzers is as follows. In a sealed cell at atmospheric pressure, the initial gas mixture of the main and analyte components, for example air and helium, is mixed, the concentration of the analyte component in the initial gas mixture is reduced to the minimum concentration C_min of the component measured by the gas analyzer in the main component, for which a time-constant flow Q of the main component is created and then supplied into a sealed cell to dilute the initial gas mixture, while to create and supply a time-constant flow Q of the main component into the sealed cell, a gas flow stimulator from the gas analyzer is used, the value of the time-constant flow Q of the main component created by the gas flow stimulator is measured from the composition of the gas analyzer, the initial concentration C₀ of the determined component is selected in the initial gas mixture in a sealed cell equal to the upper limit of the concentration of the determined component measured by the gas analyzer, the minimum concentration C_min of the determined component is selected, measured by the gas analyzer in the main component, the required total calibration duration t_cal is evaluated according to the guaranteed saving of the gas analyzer settings during the period of its continuous operation, then the volume of the sealed cell V is calculated based on the ratio V = ln(C₀/C_min)·Q·t_cal/P, where C₀ is the initial concentration of the analyte component in the initial gas mixture in a sealed cell, equal to the upper limit of the concentration of the analyte component measured by the gas analyzer; C_min is the minimum concentration of the component being determined in the main component, measured by a gas analyzer; Q is the value of the constant flow of the main component created by the gas flow stimulator from the gas analyzer; t_cal is the required total duration of gas analyzer calibration; P is the atmospheric pressure value.

EFFECT: simplification of the preparation of gas mixtures for calibrating gas analyzers and increasing the reliability of calibration results.

1 cl, 1 dwg, 1 tbl, 1 ex