Study on calibrating the quadrupole mass spectrometers with gas mixture

Abstract

• The optimal characteristic peaks can be selected through quantitative calculation. • Sensitivities of the QMS for the two-gas mixture vary linearly with the contents. • More accurate partial pressures can be calculated by the influence between gases. Quadrupole Mass spectrometers (QMS) are the main tools for partial pressure measurement, but due to their poor long-term stability, they need to be calibrated regularly. At present, the calibration of a QMS is mainly to calibrate the sensitivity in pure gas. However, the sensitivity of gases in complex environments is not completely consistent with results by using pure gases. Therefore, the change of sensitivity of QMSs in the gas mixture is studied in this paper. First, this article proposes a method for quantitatively selecting gas characteristic peaks. After that, experiments were conducted on the sensitivity of pure gas, two-gas mixtures, and multiple-gas mixtures. The experimental results show that for the two-gas mixture, the sensitivity changes linearly with the gas content. Finally, the linear relationship was used to estimate the sensitivities of the mixed gases. Estimated and actual calibration results can be considered consistent within the error range.