Product Overview
The MQ series gas sensor modules detect specific gases depending on the model — from LPG and smoke (MQ-2) to alcohol (MQ-3), carbon monoxide (MQ-7) and general air quality (MQ-135).
Each module has analogue and digital outputs, an LM393 comparator with a sensitivity potentiometer, and status LEDs.
Key Features
| Feature | Benefit |
|---|---|
| Gas-specific variants | Choose the model for your target gas |
| Analogue output | Track concentration trends |
| Digital output (LM393) | Simple threshold alarm |
| Sensitivity potentiometer | Set the alarm level |
| Power and status LEDs | See when the threshold trips |
| Three-wire connection | Easy to wire |
Applications
| Application Area | Example Projects |
|---|---|
| Home safety | Gas-leak and smoke alarms |
| Air quality | Indoor pollution monitors |
| Industry | Workshop and lab gas detection |
| Robotics | Environmental awareness |
| Education | Analogue sensor lessons |
Benefits
Easy to connect
Standard pins and supply voltages work with Arduino, ESP32, Raspberry Pi Pico and similar boards.
Well supported
Widely used part with plenty of libraries and example code.
Low cost
An affordable way to add sensing to a project.
Specifications
| Specification | Details |
|---|---|
| Sensor type | Semiconductor (metal-oxide) gas sensor |
| Supply voltage | 5 V DC |
| Outputs | Analogue and digital |
| Comparator | LM393 |
| Heater current | About 150 mA |
| Preheat | 20–60 s before readings (longer burn-in for stable values) |
| Operating temperature | −10 to +50 °C |
| Size | About 32 × 22 mm |
| Weight | About 10 g |
| Variants | MQ-2 smoke/LPG/methane/hydrogen · MQ-3 alcohol · MQ-4 methane · MQ-5 LPG/natural gas · MQ-6 LPG · MQ-7 CO · MQ-8 hydrogen · MQ-9 CO/combustible · MQ-135 air quality · MQ-136 H₂S · MQ-137 ammonia |
Why Choose This Product?
It’s a low-cost, flexible way to add gas detection — pick the variant that matches the gas you care about.
Beginner Use Cases
- Build a smoke alarm
- Make a gas-leak detector
- Monitor room air quality
- Graph sensor readings
Professional Use Cases
- Smart-building monitoring
- IoT sensor networks
- Automation triggers
- Product prototypes
Package Includes
- 1 × MQ gas sensor module (selected variant)
Please Note
- The heater draws about 150 mA — power it from a 5 V supply, not a GPIO pin
- New sensors need a burn-in period (typically 24 hours or more) before readings stabilise
- For hobby and educational use — not a certified safety alarm
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