Effect of Methanol Vapor on an MQ2-MQ7-MQ9-MQ135 Metal-Oxide Gas Sensor Array: Normalized Response Fingerprints, Dynamic Behavior, and Electronic-Nose Front-End Implications. RojavaSciTech. 2026;3(1). Accessed September 29, 2026. https://rojavajournalscitech.ac/journal/article/view/48