Description
Reviews
| Brand | - |
| Category | Robotics / STEM Teaching Tools / Sensors |
| Origin | - |
| Model Number | MQ-2-135-3-7-9 |
| Detection Gases | LPG, Propane, Hydrogen, Smoke, Alcohol, CO |
| Operating Voltage | 5V DC |
| Output Signal | Digital Switch Output (0 and 1) & Analog Voltage |
| Sensitivity Adjustment | Adjustable via Potentiometer |
| Indicator LED | Power and Alarm Status LEDs included |
| Pin Count | 4 Pins (VCC, GND, DO, AO) |
| Material | PCB with Metal Mesh Sensor Housing |
| Compatibility | Arduino, Raspberry Pi, STM32, ESP8266 |
| Preheat Time | Approximately 24-48 hours for stable readings |
Anonymous
Mar 22, 2026
Rating: 4/5
Good value but needs warm-up
The build quality is solid for the price. Just remember that it needs a long preheat time before the readings stabilize. Once warmed up, it detects alcohol and gas very reliably.
Anonymous
Mar 21, 2026
Rating: 5/5
Perfect for my home safety project
This sensor module works exactly as described. I connected it to my Arduino Uno and was able to detect smoke from a blown-out candle within seconds. The analog output allows for fine-tuning sensitivity, which is great.
Anonymous
Mar 18, 2026
Rating: 5/5
Easy to interface
Plug and play with most microcontrollers. The pinout is standard, and the potentiometer makes calibration straightforward without needing complex code initially.
Anonymous
Mar 18, 2026
Rating: 4/5
Reliable detection range
We bought ten of these for our workshop. They consistently detect LPG leaks during our tests. The only downside is the power consumption is slightly higher than expected, but acceptable for stationary use.
Anonymous
Mar 17, 2026
Rating: 3/5
Works well but sensitive to humidity
The sensor detects gas effectively, but I noticed some fluctuation in readings when the room humidity changed drastically. Good for general detection, but maybe not for precise measurement without compensation.
Anonymous
Mar 01, 2026
Rating: 5/5
Great for university projects
Used this for a final year prototype on air quality monitoring. The digital output makes it easy to set a threshold alarm. Documentation online is plentiful which helped a lot.
Q: Can I use this with a 3.3V Raspberry Pi?
A: Yes, but with caution. The VCC should ideally be 5V for the heater, but the signal pins might output 5V which can damage the Pi. We recommend using a logic level converter or a voltage divider on the output pins.
Q: Is the sensitivity fixed or can I adjust it?
A: The sensitivity is adjustable. There is a blue potentiometer on the board that allows you to set the threshold for the digital output pin (DO). Turning it changes the resistance and triggers the alarm at different gas concentrations.
Q: What is the voltage requirement for the analog output?
A: The module operates at 5V DC. The analog output voltage varies between 0V and 5V depending on the gas concentration detected. Please ensure your microcontroller's ADC can handle 5V logic.
Q: How long does it take for the sensor to be ready after powering on?
A: While the sensor may respond quickly, it requires a preheat time of approximately 24 to 48 hours for the internal heating element to stabilize and provide accurate, consistent readings.
Q: Does this sensor detect Carbon Dioxide (CO2)?
A: No, the MQ-2 module is designed primarily for combustible gases like LPG, propane, hydrogen, and smoke. It is not suitable for accurate Carbon Dioxide detection; you would need an MG-811 sensor for CO2.
Shanlian Hubei Brush Small Perfect Brush Washer - Ceramic Ink Dish, Calligraphy Cleaning Tool, Moisturizing Water Pot, Art Supply Decor
$14.20
Yanyu Mineral Water Fish Tank Stand - Triangular Bracket for Inverted Bottle Self-Made Water Circulation System
$17.05
Jingdezhen Pink Peony Flourishing Tea Canister Ceramic Lidded Loose Tea Storage Jar CYG-4578 One Jin Capacity Pu'er
$450.60
Round Sponge Brush Stamp with Mushroom Head – Printing Tool for Kindergarten Art and Kids' Crafts
$0.27
Metal Wick Centering Tool with Wooden Base for DIY Scented Candle Making
$1.28
Custom Temporary Bank Account Opening Sign, Company Signboard, Stainless Steel Door Plate, PVC Simple Plaque, Acrylic Advertising Board
$15.20
Natural Raw Crystal Diffuser Stones 500g - Same Style as Certain Summer Brand, Flameless Indoor Decor (White, Green, Purple, Yellow, Black, Blue)
$10.20
Iron Chain, Flower Pot Hanging Chain with Iron Rings, Black Suspension Chain for Bird Cages and Garden Planters
$0.10
Sheepskin Rattle with Brass Bells - Handmade Wooden Peach Wood Baby Toy for Chewing, Perfect for Children's Day
$10.80
Commercial Square Insulated Warmer Cabinet with Constant Temperature Heating, Countertop Display Case for Roast Duck, Chicken, Fried Chicken, Smoked Goose, and BBQ Meat
$338.00
PISEN Desktop Cable Organizer - Magnetic Data Cord Manager, Soft Silicone Fixed Wire Winder with Adhesive Clips, Mini Portable Hub
$10.10
Handcrafted Peach Wood and Sheepskin Rattle with Brass Jingle Stick – Traditional Chewable Wooden Baby Toy
$74.00
DC Drive DCS550-S02-0050-05-00-00
$10,838.20
Waterproof Storage Bag for Clothes and Bathroom Use, Large-Capacity Drawstring Organizer for Men and Women, Outdoor Travel and Toiletry Pack
$39.90
Steel Speed Bump with Rubber Surface for Cars and Railways
$3,668.00
Huaboshi Thickened Resin Vegetable Planter Box – Rectangular Plastic Balcony Grow Container with Drainage Tray
$45.99
New Data Cable Storage Bag Travel Digital Charger Cord Organizer Protective Visible Multi-Use Portable Case
$1.64
Press Wash Blade for KBA Printing Presses - Model KBA105 Ink Scraper, 1160*40mm
$40.50
Genuine Pirelli Run-Flat Car Tire P7 225 245 275 285/35 40 45 R18 19 20 21
$336.00
Chuangshidai 100XP Compact Desktop Fume Extractor for Soldering Irons - Rapid Smoke Purification
$696.00
Multi-Function Kitchen Sink Rack - Dish Drying Organizer for Bowls and Plates
$33.10
Water Brush Kids Water Painting Book Graffiti Special Pen Water Sketchbook Eco-Friendly Safe Tap Water Refillable Pen Set
$2.16
No-Drill Over-Toilet Storage Rack for Bathroom Restroom Organizer
$8.90
Jingdezhen Blue and White Porcelain Antique Brush Washer, Traditional Chinese Painting Calligraphy Brush Rinse Basin, Large and Small Water Pots
$16.90
Sketch Blending Stump Set for Art Students - Highlight Detail Shadow Tool Kit with Replacement Sponge Heads for Beginners
$9.00
Changyiyou Outdoor Large-Capacity Wheeled Duffel Bag - Thickened Storage Backpack with Wheels for Camping Gear and Travel
$109.00
Lightweight Waterproof Dry Bag for River Trekking and Rafting – Travel Storage for Clothes, Shoes, Socks with Moisture-Proof Buckle, Roll-Top Carry Design
$15.80
Tupai 3D Self-Adhesive Wall Stickers, Custom Acrylic Logo Advertising Letters for Signage, Background Walls, and Image Wall Decor
$8.50
Durable Replacement DEUBLIN 525/357 Water Inlet/Outlet Rotary Union for Curved Surface Printing and Cup Printing Machines
$300.00
Detachable Large Water Barrel Rack for Mineral and Purified Water, Office Bottled Water Storage Stand with Wheels
$136.00
![[Youxin Electronics] GP2Y0E03 Infrared Distance Sensor Module 4-50cm Range](https://www.gosteppe.com/cache/medium/product/74667/legacy-main-4da8cadc5fc82afe91b124e3.webp)
![[Trial Pack] Xianlang Complete Cat Treat Sticks Meal Packs Main Course Cans Freeze-Dried Cat Food Sample Snacks Gift Set](https://www.gosteppe.com/cache/medium/product/208273/legacy-main-9ec245ebf781f65a434ba854.webp)
