MQ2 Gas Sensor Module, Smoke Detection

The MQ2 Gas Sensor Module uses a Metal Oxide Semiconductor (MOS) sensing element to detect a wide range of combustible and toxic gases, including LPG, methane, propane, smoke, alcohol and hydrogen. As gas molecules contact the sensing material, its electrical resistance changes, and the module converts this into a usable analog or digital signal for your microcontroller.

Running on a 5V DC supply and consuming around 800mW, the sensor can measure gas concentrations across a broad range of 200 to 10,000 ppm. It requires a short preheat period before readings stabilise, after which it can operate continuously as either an analog or digital sensor, with sensitivity tunable through an onboard potentiometer.

• Gas detection – LPG, methane, propane, smoke, alcohol and hydrogen
• Operating voltage – 5V DC, approximately 800mW consumption
• Detection range – 200 ppm to 10,000 ppm
• Analog output – 0V to 5V
• Digital output – 0V or 5V (TTL logic)
• Preheat time – 20 seconds before stable operation
• Sensitivity adjustment – Onboard potentiometer for digital pin threshold
• Interface – Compatible with Arduino, Raspberry Pi and other microcontrollers

After powering the module and allowing it to preheat, the power LED lights up and the sensor is ready to detect gas concentrations, triggering the output LED at the set threshold or providing a continuous analog reading for finer measurement. The MQ2 Gas Sensor Module is a practical choice for smoke detectors, gas leak alarms and air-quality monitoring projects.