MQ-4 Methane Gas Sensor Module

MQ-4 Methane Gas Sensor Module Overview

The MQ-4 Methane Gas Sensor Module is a compact, low-cost gas detector optimized for methane (CH4) and common combustible gases such as natural gas, LPG and alcohol vapors. With a wide detection range and analog output, it is ideal for gas leak detection, safety monitoring and DIY environmental projects.

Key Benefits

• Reliable methane and natural gas detection for residential and industrial safety
• Wide dynamic range (200 to 10,000 ppm) suitable for both low-level monitoring and leak detection
• Analog voltage output (0-5V) provides simple, direct integration with ADC-equipped controllers
• Rapid response ensures timely alerts and quicker interventions

Technical Specifications

• Gas Detected: Methane (CH4), natural gas, LPG, alcohol vapors
• Detection Range: 200 to 10,000 ppm
• Operating Voltage: 5V DC
• Output Type: Analog (0-5V)
• Response Time: 0 seconds
• Preheat Time: 24 hours for optimal performance
• Operating Temperature: -206C to +506C
• Dimensions: ~32mm x 22mm x 27mm

Wiring and Integration

The MQ-4 module uses a simple 4-pin interface that makes it easy to connect to microcontrollers and single-board computers.

• VCC: Connect to 5V DC
• GND: Connect to ground
• A0: Analog output (0-5V) to ADC pin on Arduino/Raspberry Pi (with ADC)
• D0: Optional digital threshold output (if present on module)

Quick Arduino Integration Tip

Read the analog output with analogRead(A0) and map the ADC value to gas concentration using calibration factors. Because the sensor output is relative and influenced by environment, calibrate in clean air and at known gas concentrations for best results.

Preheat, Calibration and Maintenance

• Preheat: Allow the sensor to preheat for at least 24 hours on first use for stable readings.
• Calibration: Perform a two-point calibration if exact ppm readings are required. Use known concentration reference gases or compare to a calibrated instrument.
• Maintenance: Avoid prolonged exposure to high humidity, oils or corrosive gases. Replace after long-term drift or if responsiveness degrades.

Applications

• Gas leak detection systems for homes, commercial buildings and industrial sites
• Smart home automation and air quality monitoring
• Industrial safety monitoring in factories, workshops and laboratories
• DIY, education and maker projects using Arduino, Raspberry Pi and microcontrollers

Safety and Limitations

• This module is intended for hobby, educational and prototype use. It is not a certified life-safety device and should not replace certified gas detectors in critical applications.
• Cross-sensitivity: The MQ-4 can respond to LPG, alcohol vapors and other combustible gases. Use proper calibration and filtering to reduce false positives.
• Environmental effects: Temperature, humidity and airflow can affect readings. Compensate in software or with shielding where necessary.

Why Choose the MQ-4

The MQ-4 offers a cost-effective, easy-to-integrate solution for methane and natural gas detection. Its analog output, fast response and wide detection range make it a popular choice for prototyping, home safety projects and industrial monitoring solutions.

Note: Images are for illustration purposes only.