MQ-2 Gas Sensor Specifications

General

• Sensor Type: Semiconductor gas sensor
• Detects: LPG, Propane, Methane (CH₄), Hydrogen (H₂), Smoke, Alcohol, and other flammable gases
• Detection Method: Change in resistance of sensitive material (SnO₂)

Electrical

• Operating Voltage (module): 5 V DC
• Heater Voltage (internal): 5 V ± 0.2 V
• Heating Current: ~150 mA
• Output Types:
  • Analog output (AO) – proportional to gas concentration
  • Digital output (DO) – HIGH/LOW via onboard comparator
• Interface Pins: VCC, GND, AO, DO

Performance

• Detection Range (general): 300 ppm – 10,000 ppm (varies by gas)
• Sensitivity: High for LPG and Propane
• Preheat Time: 20–30 seconds (minimal), optimal 24–48 hours for stable calibration
• Response Time: <10 seconds
• Recovery Time: <30 seconds
• Operating Temperature: −20°C to +50°C
• Humidity Range: 30% – 95% RH

Physical

• Sensor Diameter (bare sensor): ~16 mm
• Module Size: ~32 mm × 20 mm (varies by manufacturer)
• Mounting: 2–4 holes depending on module board design

Features

• Adjustable sensitivity (via onboard potentiometer)
• Indicator LED for digital output
• Long service life and stable performance
• Suitable for DIY smoke detectors, gas leakage alarms, and air-quality monitoring