In FCC-hh one of the most challenging issue will be the control of all possible instabilities that could occur. In order to do so,most simulation programs need realistic inputs measured in experimental conditions as close as possible to the ones that will occur in the machine. Most of the accelerators walls will see the beam while being at low temperatures and their relevant properties will not only depend on the technical materials but also on the presence of cryosorbed residual gas condensed on cold surfaces. Gas layers may affect vacuum stability and secondary electrons yield even in case of tiny wall temperature fluctuations. Studying SEY,it’s possible to obtain direct information about its value,which is of great relevance in e-cloud related simulations,and on the presence of any gas overlayer. In fact,SEY depends both on the bulk and the surface composition,giving direct information about surface contamination and on different adsorbed gases and molecules.Here we present a study on the SEY of a Cu surface exposed at low temperature to different gases.Adsorption and desorption occurring in different temperature ranges change the SEY that can be directly correlated with the number of layers adsorbed. The measure of SEY it’s used here,for the first time,as a novel technique to extract relevant information on the actual adsorption/desorption process. Such SEY studies are compared with Quadrupole mass spectrometry showing the potentialities of the new approach here proposed.