MQ-9 Gas Sensor Module for CO, Methane & LPG Detection
MQ-9 Gas Sensor Module
The MQ-9 gas sensor module detects carbon monoxide (CO), methane (CH₄), and liquefied petroleum gas (LPG). It’s widely used in air quality monitors, gas leak alarms, and industrial safety equipment. The module outputs both analog voltage and a digital TTL signal, making it easy to integrate with microcontrollers for threshold-based alerts or concentration monitoring.
Key Specifications
| Specification | Value |
|---|---|
| Gas Detected | CO, Methane, LPG |
| Detection Range | 10–1000 ppm CO; 300–10,000 ppm Methane/LPG |
| Operating Voltage | 5 V DC |
| Output Type | Analog (0–5 V) and Digital (TTL) |
| Preheat Time | 60–120 seconds (initial) |
What You Can Build With This
- Carbon monoxide leak alarm with buzzer and LED indicators
- Methane leak detector for kitchen or basement safety
- Portable air quality monitor with an LCD or OLED display
- Smart home gas alert system using an ESP8266 and cloud notifications
Compatibility
The module works with any 5V microcontroller board including Arduino Uno, Nano, and Mega. It can also interface with 3.3V boards like ESP8266, ESP32, or Raspberry Pi when using a logic level shifter or voltage divider for the digital output. The analog output requires an ADC input on the host board.
Wiring Notes
Connect VCC to 5V, GND to ground, AOUT to an analog input (e.g., A0), and DOUT to a digital pin. The heater draws around 150 mA during the high-heat cycle, so avoid powering the module directly from a microcontroller’s 5V pin; use an external regulated supply.
Why Buy from Compoden
Every component is sourced from verified suppliers and tested for compatibility before listing. We've spent 10 years building projects for makers, schools, and institutions across India. Ships from Bengaluru in 3-5 days. If defective on arrival, replace within 7 days.
Is this compatible with Arduino?
Yes, the MQ-9 module operates at 5V and connects directly to any Arduino board. Use an analog pin to read gas concentration and a digital pin for the threshold alarm.
How do I calibrate the sensor?
Allow it to preheat for at least 2 minutes. For the digital output, adjust the onboard potentiometer until the threshold triggers in clean air. For analog accuracy, expose the sensor to a known concentration and map the voltage readings.
Can it detect smoke from a fire?
The sensor is optimized for CO, methane, and LPG, not particulate smoke. It may respond weakly to combustion gases present in smoke, but it is not a substitute for a dedicated smoke detector.
📦 Free Setup Handoff Document Included
Every Compoden order includes a free setup handoff document — step-by-step instructions to get your component working within minutes. Download it via QR code on your package. The handoff document is also trained to help you troubleshoot the majority of problems.
What you can build with this
Shipping Information
- Prepaid Orders: ₹75 for orders up to ₹999, FREE shipping above ₹999
- COD Orders: ₹125 shipping + ₹50 COD fee = ₹175 total
- Delivery Timeline: Dispatch in 1-2 days, delivery in 2-7 days depending on location
Returns & Warranty
- 7-Day Return: Manufacturing defects only (approval required)
- Warranty: 7 days from delivery
- Non-Returnable: Batteries, consumables, cut wires, clearance items