Abstract
A gas sensing system includes an air intake hole which comprises a plurality of micro-flow channels, a replaceable sensor for receiving an air from the air intake hole and detecting the received air, and a processing unit coupled to the replaceable sensor and doing determination for the component of the air according to a detection result of the replaceable sensor. Wherein, the replaceable sensor includes a plurality of sensing chips arranged in an array and each sensing chip is coated with a sensing thin film separately to detect a different gas.