Hi seekers! Welcome to another article discussing a sensor from the MQ gas sensor series. Today, we are discussing the MQ-9 gas sensor, which can detect gases like carbon monoxide, CH4, and LPG. It has a long life and a simple structure, and the heart of this gas sensor is the sensing element on the heating circuit. Usually, such sensors are part of large projects where they sense the target gas and send a signal for any alarming condition. Libraries MQ-9 Simulation Libraries Latest library: MQ Gas Sensor Library for Proteus V1.0 (October 2026) Other gas and fire sensors: Gas MQ-2 · MH-Z19B CO2 · PMS5003 · CCS811 · Flame Sensor Helping Tools Serial Monitor Advance : a serial terminal window for the UART of your board Serial Monitor Expert : the serial monitor with extra debugging tools LCD ...