Description
Reviews
| Brand | - |
| Category | Robotics / STEM Teaching Tools / Sensors |
| Origin | - |
| Model Number | MQ-2-135-3-7-9 |
| Detection Gases | Smoke, LPG, Alcohol, Hydrogen, CO |
| Operating Voltage | 5V DC |
| Output Signal | Analog and Digital (TTL) |
| Preheat Time | 24-48 Hours |
| Sensitivity Adjustment | Potentiometer Included |
| Interface Type | 3-Pin Header (VCC, GND, OUT) |
| Dimensions | 32mm x 20mm x 15mm |
| Compatibility | Arduino, Raspberry Pi, ESP32 |
| Mounting Style | Through-hole with Standoffs |
Anonymous
Mar 29, 2026
Rating: 5/5
Reliable gas detection
Integrated this into my smart home system to monitor the garage for fuel leaks. It picks up hydrogen and combustible gases quickly. The digital output pin is a nice feature for simple alarm triggers.
Anonymous
Mar 18, 2026
Rating: 5/5
Great addition to my greenhouse monitor
Using this to monitor air quality and potential fermentation gases in my composting area. It responds well to changes in air composition. The build quality feels sturdy enough for long-term use.
Anonymous
Mar 15, 2026
Rating: 4/5
Good sensitivity, needs patience
The sensor is very sensitive to alcohol and smoke as advertised. Just remember to let it warm up for at least 24 hours before calibrating, or your readings will be all over the place. Once calibrated, it's solid.
Anonymous
Mar 14, 2026
Rating: 4/5
Works well but gets hot
Functionality is top-notch for the cost. Be aware that the heating element inside gets quite hot during operation, which is normal for this type of sensor, but ensure your enclosure has ventilation.
Anonymous
Mar 06, 2026
Rating: 5/5
Excellent for learning embedded systems
Bought this for a university project on air quality monitoring. The documentation provided by the seller was helpful, and the potentiometer makes threshold adjustment very easy. Highly recommended for students.
Anonymous
Mar 04, 2026
Rating: 5/5
Perfect for home safety projects
This sensor module works flawlessly with my Arduino setup. The analog output is stable after the initial preheat time, and detecting smoke from a simple test was immediate. Great value for the price.
Q: Does this module require an external library to work with Arduino?
A: No external library is strictly required. You can read the analog value using the standard analogRead() function. However, many users find community libraries helpful for calibration and unit conversion.
Q: Can this detect natural gas specifically?
A: Yes, the MQ-2 sensor is sensitive to methane and other combustible gases found in natural gas, though it is not specific to one gas type and reacts to a range of combustible vapors.
Q: Is the digital output adjustable?
A: Yes, there is a blue potentiometer on the board that allows you to adjust the sensitivity threshold for the digital output pin (DO). Turning it changes the point at which the LED lights up and the signal goes low.
Q: What is the exact preheat time needed before accurate readings?
A: For stable and accurate baseline readings, we recommend a preheat time of 24 to 48 hours. Shorter periods may result in fluctuating values as the sensor element stabilizes.
Q: What is the power consumption of this module?
A: The module typically consumes around 150mA to 200mA at 5V due to the internal heating element required for the sensor to operate correctly. Ensure your power supply can handle this load.
Rubber Speed Bump End Cap Heavy-Duty 1 Pack
$72.46
Front Wiper Arm Assembly for Citroën C-Elysée, Xsara Picasso, Peugeot 307/301
$35.00
Underbite Corrector Case - Portable Magnetic Lanyard Storage Box for Frankel Appliance and TB Palatal Expander
$22.70
Car Tire Stone Removal Tool, Multi-Function Hook for Picking and Extracting Stones from Treads
$6.43
Outdoor Lamp Stand for Camping, Lantern Holder Pole for Street Vending and Night Fishing
$13.89
Waste Removal and Paper Stacking Machine, Automatic Paper Collection and Counting Receiver for Carton Printing Equipment, Carton Factory Machinery
$6,400.00
Sheepskin Baby Rattle - Chewable Traditional Handmade Shaker Bell, Intangible Cultural Heritage Essential for Newborn Care
$57.00
Zhizhi Study Room 'Small Pot Sky' Brush Washer - Traditional Handmade Glass with Lost-Wax Method, Silk Luster, Double-Compartment Water Vessel
$457.00
Zao Boshi Insulated Food Cart - Programmable Banquet Warmer for Buns, Breakfast Items, and Hotel Dry/Wet Dishes
$11,566.00
![Lichuan JK [Blood Oath] - Original Authentic Japanese Dark Style Embroidered Sailor Suit - Spring/Autumn Set](https://www.gosteppe.com/cache/small/product/269363/legacy-main-0b86f0b7795c15ee2c8be0d3.webp)
Lichuan JK [Blood Oath] - Original Authentic Japanese Dark Style Embroidered Sailor Suit - Spring/Autumn Set
$59.00
Sink Storage Rack Stainless Steel No-Drill Kitchen Sponge Steel Wool Cloth Pot Lid Organizer Wall-Mounted Drain Rack
$4.93
Sketch Blending Stump Set for Artists - Detail Highlight and Shadow Smudging Tools with Replacement Tips
$14.80
Softening Agent for Board Arcs Melamine Softener Eco-Friendly Board Paint-Free Board Whole House Customization Arc Softener
$9.30
Car Tire Stone Removal Tool - Hook Picker for Cleaning Pebbles from Vehicle Treads
$3.90
Electrical Box with PLC System and VFD for Fans and Pumps
$2,519.00
Zunjue Watercolor Sketchbook 300g Fabric-Covered Journal – Portable Acrylic Marker Book, 100% Cotton Flip-Style Concertina Drawing Paper
$13.70
French Imported Arches Watercolor Paper, Handmade Cotton Pulp 300g Full/Half/4K/8K/16K/32K Rough/Medium/Fine Grain, 185g Cotton Pulp for Postcards and Watercolor Books
$20.80
![[Official Authentic] Zichao Bear Wanda Cinema Popcorn Acrylic Keychain Plush Doll Cute Toy](https://www.gosteppe.com/cache/small/product/269355/legacy-main-ae40bf0d9a6007e2f30a9130.webp)
[Official Authentic] Zichao Bear Wanda Cinema Popcorn Acrylic Keychain Plush Doll Cute Toy
$25.40
Heidelberg Printing Press Automatic Blanket Wash Cloth - Non-Woven Cleaning Fabric, 500m Roll
$3,185.00
Bucket Pack Natural Wood Colored Pencils Water-Soluble for Kids Coloring and Doodling
$6.65
Chunfei Grocery Store Yunm'an GR02 Gravel Bike - Thru-Axle Disc Brake, Lightweight Touring with Multiple Rack Mounts
$6,444.00
Variable Frequency Drive Power Board ZPOW-591 for ACS880
$2,200.00
Professional Sketching Eraser Kit - Blending Stumps, Sponges, and Paper Tortillons for Highlight & Shadow Correction
$3.90
Weighted Water Bag with Handle, Thickened PV Mesh Gravity Ballast for Banner Stand Fixation (8KG)
$35.10
Ultra-Fine Purification Lint-Free Cloth Cleaning Cloth Lens Wipe High Quality 0730 Water-Absorbing Dust Removal UV Nozzle 100 Sheets
$96.00
Wen Zhengming Small Regular Script Calligraphy Cards: Li Sao Jing, Thousand Character Classic, Qin Fu, Cao Tang Shi Zhi, Qing Jing Jing, Record of the Drunken Pavilion, Red Cliff Ode
$59.00
Zhizhi Manshu Zhao Mengfu Small Regular Script Collection of Ancient Classics (Vol. 1) - Calligraphy Copybook, Brush Writing Cards, Foldable Practice Cards
$49.00
Language of Drums Motion Path Set - Essential Creativity and Rhythm Teaching Material for Drum Kits and Jazz Drums
$59.14
onlycook Sink Drain Basket, Faucet-Mounted Food Residue Separator and Washing Strainer - 1 Pack
$14.10
Heavy-Duty Wiper Arms and Blades for Trucks and Agricultural Vehicles - Universal Replacement Wiper Rubber Strips
$5.50
![[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)
