DFRobot
Gravity: Arduino CO/Combustible Gas Sensor (MQ9)
The Gravity MQ-9 gas sensor detects carbon monoxide (CO) and combustible gases including methane and propane. It uses a semiconductor SnO2 sensing element th...
The Gravity MQ-9 gas sensor detects carbon monoxide (CO) and combustible gases including methane and propane. It uses a semiconductor SnO2 sensing element that cycles between high and low temperatures — detecting CO at low temperature (1.5V) and combustible gases at high temperature (5.0V).
With a DFRobot Gravity interface, the sensor connects directly to any Arduino analog input for plug-and-play operation. Sensitivity is adjustable via an onboard potentiometer, and the analog output is proportional to gas concentration.
Key Features
- Dual Gas Detection – Detects both CO (10–1,000 ppm) and combustible gases (100–10,000 ppm)
- High Sensitivity – Particularly responsive to methane, propane, and carbon monoxide
- Gravity Interface – Plug-and-play analog connection to Arduino boards
- Adjustable Sensitivity – Onboard potentiometer for fine-tuning detection thresholds
- 5V Power Supply – Standard voltage for easy integration
- Compact Size – 36.4 × 26.6 mm (1.43" × 1.05")
Ideal For
- Domestic gas leakage detectors
- Industrial gas monitoring systems
- Portable gas detection devices
- Air quality monitoring projects
Package Contents
- 1× MQ-9 CO/Combustible Gas Sensor
- 1× Gravity Analog Cable
Resources
Jargon buster
Plain-language definitions for the technical terms used above.
- Gravity
- Gravity is DFRobot’s plug-in connector system for sensors, motors and modules, using standard cables to reduce loose jumper wiring. It matters because Gravity-compatible parts can connect directly to these ports, while non-Gravity parts may need adapters or manual wiring.
- potentiometer
- A variable resistor usually turned with a knob or shaft to create an adjustable electrical signal. It is often used for inputs such as volume, brightness or position, so it helps beginners learn how a microcontroller reads changing values.
- ppm
- ppm means parts per million, a common way to express very small gas concentrations in air. For CO₂ sensors, the ppm range tells you what levels the sensor can measure, such as normal indoor air through to poorly ventilated spaces.
Find this product in
Brands
Supplier page — dfrobot.com
Supplier Description · 1.1 MB · Click any page to view full size
Related Tutorials
Free guides on learn.littlebird.com.au
