MQ4 GAS SENSOR

🔹 MQ-4 Gas Sensor Module – Methane (CH₄) & Natural Gas Detector

The MQ-4 is a high-sensitivity semiconductor gas sensor designed specifically for detecting Methane (CH₄) and natural gas (CNG/LNG) concentrations in the air. It provides both analog and digital outputs, making it ideal for gas leak detection, natural gas monitoring, and industrial safety applications with Arduino, ESP32, and other microcontrollers.

✅ Specifications:

• Sensor Type: MQ-4 Metal Oxide Semiconductor (MOS)

• Target Gas: Methane (CH₄), Natural Gas (CNG/LNG)

• Detection Range: 200 – 10,000 ppm (methane)

• Operating Voltage: 5V DC

• Heater Voltage: 5V AC/DC

• Heater Power Consumption: ≤ 900mW

• Load Resistance: Adjustable (via onboard potentiometer)

• Output Signals:

  • Analog: 0–5V (proportional to gas concentration)

  • Digital: TTL (trigger threshold adjustable via potentiometer)

• Module Interface: 4-pin header (VCC, GND, DO, AO)

• Onboard Features: Power LED, Status LED, Sensitivity adjustment potentiometer

• Preheat Time: ≥ 48 hours (for initial stabilization)

• Dimensions: ~32mm x 20mm x 22mm

• Operating Temperature: -10°C to +50°C

📦 Features:
✔️ High sensitivity to methane (CH₄) and natural gas
✔️ Good selectivity (low sensitivity to alcohol, smoke, LPG)
✔️ Fast response and recovery time
✔️ Simple drive circuit (analog voltage output)
✔️ Long life and stable performance
✔️ Both analog and digital outputs
✔️ Compact module with indicator LEDs

📦 Applications:
✔️ Natural gas leak detection (homes, kitchens, factories)
✔️ Methane monitoring in biogas plants
✔️ Coal mine gas detection
✔️ Industrial safety systems
✔️ Gas alarm and shut-off systems
✔️ Arduino and IoT-based gas detection
✔️ Laboratory gas monitoring
✔️ Agricultural and livestock waste monitoring

⚠️ Important Notes:

• Preheat time is critical. For accurate readings, the sensor requires 24-48 hours of initial stabilization.

• Calibration recommended. For precise measurements, calibration against known methane concentrations is advised.

• Cross-sensitivity. The sensor may respond to other combustible gases (hydrogen, ethanol, smoke). Refer to the datasheet for selectivity details.

• Requires a stable 5V power supply capable of providing sufficient current for the heater (~180mA).