METHOD FOR PREPARATION OF GAS MIXTURES CERTIFIED FOR FLUORINE HYDROGEN CONTENT Russian patent published in 2018 - IPC G01N1/38 G01N21/3504 

FIELD: chemistry.

SUBSTANCE: invention relates to the field of analytical chemistry and relates to a method for preparing gas mixtures certified for hydrogen fluoride content and intended for the calibration of the FTIR spectrometer. This method comprises preparation of the source gas mixture in a temperature controlled gas cell of the FTIR spectrometer with the subsequent registration of the IR spectrum, gradual dilution of the gas mixture with a diluent gas in the gas cell, registration of the IR spectrum of the gas mixture with a changed concentration, and determination of the calibration characteristic using the registered IR spectra. Further, the incremental change of the gas mixture is carried out from a higher concentration to a lower one, the preparation of the calibration gas mixture is carried out at a total pressure of the mixture from 50 to 120 mm Hg, the content of impurities in the gas mixture is in the range from 0.001 to 0.1 mol. %, the gas cell is thermostatted at a temperature of at least 80 °C.

EFFECT: technical result consists in providing the possibility of executing the measurements with a low content of hydrogen fluoride.

1 cl, 5 dwg, 2 tbl