MQ-9 Gas Sensor Module for Carbon Monoxide, Methane & LPG Detection

About MQ-9 Gas Sensor

The MQ-9 Gas Sensor Module is a compact and reliable solution for detecting harmful and combustible gases such as Carbon Monoxide (CO), Methane, and LPG. Built using a sensitive SnO₂ (tin dioxide) sensing element, this module reacts to the presence of gases by changing its conductivity, allowing accurate detection in real-time.

Designed for both beginners and advanced electronics enthusiasts, the MQ-9 uses a dual-temperature operating method to improve detection accuracy. It alternates between low and high heating cycles—detecting Carbon Monoxide at lower temperatures and combustible gases like Methane and Propane at higher temperatures. This makes it a versatile choice for multiple gas sensing applications.

The module provides both analog (AO) and digital (DO) outputs, making it easy to interface with microcontrollers like Arduino, ESP32, and Raspberry Pi. With a simple drive circuit and long operational life, it is perfect for safety systems, home automation projects, and industrial monitoring setups.

Key Features:

• High sensitivity to Carbon Monoxide (CO) and combustible gases
• Detects Methane, LPG, and Propane effectively
• Dual output: Analog and Digital signals
• Long lifespan with stable performance
• Simple interfacing with microcontrollers
• Cost-effective gas sensing solution

Applications:

• Domestic gas leakage detection systems
• Industrial safety monitoring
• Portable gas detectors
• Smart home automation projects

Pin Configuration:

• VCC – 5V Power Supply
• GND – Ground
• DO – Digital Output (TTL signal)
• AO – Analog Output

Technical Specifications:

• Operating Voltage: 5V
• Model: MQ-9
• Current Consumption: ~150mA
• Analog Output: 0.1–0.3V (clean air)
• Digital Output: TTL (0 or 5V)
• Dimensions: 32 × 20 × 16 mm
• Weight: 5g

Package Includes:

• 1 x MQ-9 Gas Sensor Module