Identifying gas composition based on the decomposed relaxation strength from sound-speed dispersion

Measuring the sound-speed dispersion in excitable gases demonstrates its potential for gas detection owing to its low measurement error. However, identifying the gas composition of a multi-component gas mixture remains a challenge in this method. The relaxation strength of the gas mixture determines the change in speed dispersion and depends on the gas composition. In this paper, we propose a method for identifying the gas composition based on relaxation strength. First, we extracted the decomposed relaxation strength from sound-speed dispersion and clarified the contribution of individual gas compo-nent to the decomposed relaxation strength. Second, we identified the gas composition by the relative change in the decomposed relaxation strength due to the variation in the environment temperature, and calculate the gas concentration by the ratio of the decomposed relaxation strength to the relaxation strength of the corresponding pure gas. Thus, complete identification can be performed for a multi -component gas mixture using the proposed method. For gas mixtures containing CO2; CH4 and N2, the simulations and experimental results validated the robustness and effectiveness of the proposed method.(c) 2023 Published by Elsevier Ltd.