MQ-2 Gas and Smoke Sensor Module (LPG, Propane, Methane Detection)

A general-purpose combustible gas and smoke detector

The MQ-2 module detects a wide range of combustible gases and smoke, including LPG, propane, methane, hydrogen, butane, alcohol vapors and smoke itself, making it a genuinely broad-spectrum sensor for home safety and gas leak detection rather than one tuned narrowly to a single gas. That range covers most of the common combustible gas hazards found in a typical home or workshop, from a stove gas leak to general smoke from a fire.

It provides both analog output (0 to 5V) for a graduated sense of gas concentration and digital output (0V or 5V TTL logic) for a simple threshold-based alarm trigger, and sensitivity is adjustable through an onboard potentiometer, letting the trigger point be tuned depending on how cautious or how tolerant of background gas levels a specific installation needs to be.

Setup and applications

Operating voltage is 5VDC, and the module includes status LEDs that give an immediate visual indication of power and detection state, useful for quickly checking whether the sensor is working or currently triggered without needing to check a connected microcontroller. Response time is fast, and the module works directly with Arduino, ESP32, NodeMCU and Raspberry Pi boards without extra interfacing hardware.

Listed applications include home safety systems, air quality control, gas level measurement, leakage alarms and IoT safety systems, reflecting its role as a general early-warning sensor for combustible gas presence rather than a precision gas-concentration measurement instrument.

Who it suits

Anyone building a home gas leak alarm, a kitchen safety monitor, or a general smoke and combustible gas detection project will find the MQ-2's broad gas sensitivity and dual analog/digital outputs a practical, well-supported safety sensor.

Questions buyers ask

What gases does it detect?

LPG, propane, methane, hydrogen, butane, alcohol vapors and smoke.

What outputs does it provide?

Both analog (0-5V) and digital (0V/5V TTL) outputs.

Can the sensitivity be adjusted?

Yes, through an onboard potentiometer.