MQ-2 Gas Sensor Module

The MQ Gas Sensor Module is a versatile gas detection module designed to detect various combustible, toxic, and harmful gases in the surrounding environment. It is based on the popular MQ series gas sensor, which uses a tin dioxide (SnO₂) sensitive layer whose conductivity changes when exposed to target gases. The module integrates the gas sensor element, an LM393 voltage comparator, sensitivity adjustment potentiometer, power indicator, and digital output indicator LED, making it easy to interface with microcontrollers. It provides both Analog (AO) and Digital (DO) outputs, allowing users to measure gas concentration or simply detect whether a preset gas threshold has been exceeded. Depending on the installed MQ sensor variant, the module can detect gases such as LPG, propane, methane, hydrogen, alcohol, carbon monoxide, smoke, natural gas, ammonia, benzene, and air pollutants. It is widely used in gas leakage alarms, air quality monitoring, industrial safety systems, smart homes, environmental monitoring, and IoT applications.