The MQ4 Methane Natural Gas Sensor Module is a semiconductor gas sensor designed to detect methane (CH₄) and natural gas leaks with high sensitivity. Using a tin dioxide (SnO₂) sensing layer, it changes resistance in the presence of target gases, enabling reliable detection for safety systems, gas leak alarms, and IoT-based environmental monitoring. The module provides both analog and digital outputs, making it easy to integrate with microcontrollers.
Core Sensor Specifications
• Sensor Type: Semiconductor gas sensor
• Sensor Model: MQ4
• Target Gases: Methane (CH₄), Natural Gas
• Output Type: Analog and Digital (threshold-based)
Electrical & Interface
• Operating Voltage: 5 V DC
• Heater Voltage: 5 V DC
• Interface Pins: VCC, GND, AO, DO
• Digital Output: Comparator with adjustable threshold
• Warm-Up Time: Required for stable readings
Performance Characteristics
• Detection Range: ~300 – 10,000 ppm (methane)
• High sensitivity to methane gas
• Fast response and recovery
• Performance affected by temperature and humidity
Physical Characteristics
• Module Type: PCB-mounted gas sensor module
• Sensor Element: Metal can package
• Onboard Components: LM393 comparator, potentiometer
• Compact and robust construction
Compatibility
• Arduino Uno / Nano / Mega
• ESP8266 / ESP32
• STM32, AVR, PIC microcontrollers
• Raspberry Pi (with ADC for analog output)
Key Advantages
• Reliable methane and natural gas detection
• Dual output (analog + digital)
• Adjustable sensitivity via onboard potentiometer
• Widely used and well documented sensor
Technical Insights
• Requires preheating (24–48 hours for first use)
• Analog output suitable for ppm estimation after calibration
• Not selective—may respond to other combustible gases
• Best used for detection rather than precise measurement
Applications
• Gas leak detection systems
• Home and industrial safety alarms
• IoT gas monitoring
• Smart kitchens and gas pipelines
• Educational and research projects
Pro Tip
• Allow sufficient warm-up time before calibration
• Use analog output for trend analysis
• Calibrate in clean air for better accuracy
• Install sensor near potential leak sources
Package Includes
• 1 × MQ4 Methane Natural Gas Sensor Module