Environment pollution has pushed an increasing interest in the development of automated and intelligent systems for monitoring and analysing environmental variables. Odor sensing is generally applied to security, elderly care, food quality control, and domestic gas leakage or fire detection. In this field, recent applications of mobile robotics systems are being considered, more specifically, the detection of an odour source by a mobile robot. In this paper, an ethanol odor field, coming from a source, is measured using Metal Oxide Semiconductors sensors. An explore- exploit-based algorithm, which makes use of this environment information, is implemented in a mobile robot by combining the spiral and the plume-centered upwind search algorithms. Simulation results validate the robot performance during an odor detection task.