MQ-2 Gas Sensor Explained 🔍 | Features, Advantages & Applications

The MQ-2 Gas Sensor is a highly popular and affordable sensor used to detect gases like LPG, methane, alcohol, propane, hydrogen, CO, and smoke. If you’re building a gas leakage detector, air quality monitor, or smart safety system, this sensor is a must-have for your electronics toolkit.

Let’s explore what makes the MQ-2 special, how it works, and why you should use it in your next project!

📦 What is the MQ-2 Gas Sensor?

The MQ-2 is a metal oxide semiconductor (MOS) sensor that changes its electrical resistance in the presence of gases. It’s widely used in Arduino, Raspberry Pi, and IoT projects for detecting combustible and harmful gases.

⚙️ Key Features of the MQ-2 Sensor:

• 🔌 Operating Voltage: 5V DC

• 🌫️ Detectable Gases: LPG, methane, propane, hydrogen, CO, alcohol, smoke

• 🎛️ Analog and Digital Output

• 🔁 High sensitivity and quick response time

• 🔄 Adjustable sensitivity via onboard potentiometer

• 📏 Long sensing life and low cost

🧪 How Does the MQ-2 Work?

The sensor has a heating element inside that heats the sensing layer (tin dioxide). When gas is present, it reacts with the sensor’s surface and causes a change in resistance. This change is read by the analog pin and can be used to trigger alarms, notifications, or automation systems.

👉 Works best in well-ventilated environments
👉 Needs calibration for best accuracy (based on your use case)

✅ Advantages of Using MQ-2:

✔️ Wide gas detection range
✔️ Low cost & widely available
✔️ Easy to interface with Arduino, ESP8266, NodeMCU, etc.
✔️ Compact and lightweight
✔️ Dual output (Analog + Digital)
✔️ Perfect for IoT and safety projects

🧰 Common Applications:

• 🔔 Home gas leak alarms

• 🌬️ Air quality monitoring

• 🏭 Industrial gas detectors

• 🔧 DIY Arduino-based safety systems

• 🚗 Car smoke detectors

• 🌐 Smart home integration with alerts