The paper discusses the results of numerical analysis of the properties and modes of the adsorption air separation process and oxygen concentration with purity of ∼90% carried out in a double-adsorber PSA unit with a 13X granular zeolite adsorbent with capacity of up to 2 l/min. Calculation experiments have been performed using the developed mathematical model and the influence of perturbations (temperature, composition and pressure of atmospheric air) on the dynamics of the process, the unit performance, the extraction degree and oxygen purity has been investigated. It has been established that the most effective control action is the pressure at the compressor outlet, the increase in which from 2 to 6×105 Pa leads to the increase in the extraction degree and oxygen concentration on average by ∼57% and ∼12 vol.% respectively.