Abstract The present work deals with adsorption/desorption process of NO on activated carbon. The goal of the experiments was to determine under which conditions is the activated carbon bed able to damp down the concentration fluctuations of NO in the gas entering the bed. It was found out that the residence time necessary to balance out the input concentration fluctuations of NO increases along with the average concentration of NO. The minimum mean residence time of 3–9 min was found as necessary to level the average NO concentration ranging from 357 to 1428 ppm. The decisive parameters for the extent of attenuation are discussed in the terms of linear driving force model for fixed-bed adsorber dynamics.