A database comprising a digital signature of a smell, the digital signature comprising a smell data, the smell data comprising a response signal that is a function of a first data corresponding to a generator generating the response signal and a second data corresponding to a predetermined stimulus for generating the response signal, wherein the digital signature comprises binary data, wherein the response signal is a measurable response of the generator to the predetermined stimulus that is a function of change in electrical properties of resistance or impedance in the generator. wherein the generator generating the smell-related response signal is a Metal Oxide Semiconductor (MOS) in a sensor or a sensor pixel of a sensor array having a plurality of MOS sensor pixels having an MOS active material exposed to an analyte in the gas environment and the predetermined stimulus is a sequence of predetermined temperatures.