Metal-Oxide (MOx) electronic nose (e-nose) sensor recordings, for odour pulses of various concentration levels This data is a subset of a larger, yet unpublished dataset - collected by the following authors: Dennler N., Drix D., Warner T., Rastogi R., van Schaik A., Schaefer A., Schmuker M. The custom-made electronic nose used to collect the data is a successor of the device described in Drix & Dennler et al. [1]. It comprises four Metal Oxide (MOx) gas sensors operated at a constant heater voltage, and . The odour stimuli were provided by a multi-channel odour delivery device that is described in detail by Ackels et al. [2]. It offers a high temporal fidelity, which is achieved by combining high-speed gas valves, flow controllers, as well as short and narrow gas pathways. The data collection comprises of recordings where odourant headspace samples were embedded in constant airflow and presented to the e-nose. Data of four different odourants were used: Ethyl Butyrate (EB), Eucalyptol (Eu), Isoamyl Acetate (IA), and 2 - Heptanone (2H). EB, Eu and IA gases were diluted in mineral oil at a ratio of 1 : 5, and 2H was diluted in a ratio of 1:50. The delivered odour concentration was varied by modulating the valve shutter duty cycle, ensuring a linear relationship between five different concentration levels (E.g. C5 = 5 x C1). Fluctuations in flow during gas presentations were minimized by careful calibration. The filenames consist of the timestamp (in processor time), the gas identity, and a concentration level between 1 and 5. [1] D. Drix, N. Dennler and M. Schmuker, "Rapid Recognition of Olfactory Scenes with a Portable MOx Sensor System using Hotplate Modulation," 2022 IEEE International Symposium on Olfaction and Electronic Nose (ISOEN), Aveiro, Portugal, 2022, pp. 1-4, doi: 10.1109/ISOEN54820.2022.9789654. [2] Ackels, T., Erskine, A., Dasgupta, D. et al. Fast odour dynamics are encoded in the olfactory system and guide behaviour. Nature 593, 558–563 (2021). https://doi.org/10.1038/s41586-021-03514-2