Description
Reviews
| Brand | - |
| Category | Robotics / STEM Teaching Tools / Sensors |
| Origin | - |
| Model Number | MQ-135 |
| Detection Gases | Ammonia, NOx, Alcohol, Benzene, Smoke, CO2 |
| Operating Voltage | 5V DC |
| Output Signal | Analog and Digital (TTL) |
| Heater Voltage | 5.0V ± 0.2V |
| Load Resistance | Adjustable via Potentiometer |
| Preheat Time | 24 Hours (Recommended) |
| Interface Type | 3-Pin Header (VCC, GND, OUT) |
| PCB Dimensions | 32mm x 20mm |
| Application | Arduino, Raspberry Pi, DIY Air Quality Monitors |
Anonymous
Mar 29, 2026
Rating: 4/5
Easy to integrate
As a beginner, I found this easy to wire up. The pins are clearly labeled. My only issue was understanding the raw data values at first, but after finding a library online, it works perfectly.
Anonymous
Mar 19, 2026
Rating: 5/5
Reliable and sensitive
I bought two of these for a classroom air quality demonstration. They are highly sensitive to changes in air composition. The dual output (analog and digital) gives flexibility for different coding approaches.
Anonymous
Mar 18, 2026
Rating: 3/5
Works but gets hot
Functionality is fine for basic detection, but the heating element gets quite warm during operation. Make sure your enclosure has ventilation. Documentation could be better, but there are plenty of tutorials online.
Anonymous
Mar 07, 2026
Rating: 5/5
Perfect for my smart home project
This sensor works exactly as described. I connected it to my Arduino Uno and was able to read analog values within minutes. The potentiometer makes calibrating the digital threshold very easy. Great value for the price.
Anonymous
Mar 05, 2026
Rating: 4/5
Good sensor, requires patience
The module is well-built and the soldering points are clear. Just remember that it needs a long preheat time (about 24 hours) before the readings stabilize. Once warmed up, it detects smoke and alcohol vapors very quickly.
Anonymous
Mar 05, 2026
Rating: 5/5
Great for monitoring ventilation
Using this to monitor ammonia levels in my small greenhouse setup. It triggers my exhaust fan when levels rise. Very responsive and the build quality seems durable for indoor use.
Q: Does this module work with 3.3V logic boards like the ESP8266?
A: Yes, the digital output is TTL compatible, but for the analog output, you may need a voltage divider if your board's ADC cannot handle 5V. The heater requires 5V to operate correctly.
Q: How long does it take for the sensor to give accurate readings?
A: While it responds quickly to gas presence, we recommend a continuous preheat time of 24 hours for the first use to stabilize the internal sensing element for accurate baseline readings.
Q: Is there a library available for Arduino?
A: Yes, there are several open-source libraries available in the Arduino Library Manager. Search for 'MQ135' to find calibration and reading examples contributed by the community.
Q: What is the power consumption of this module?
A: The heating element consumes approximately 150mA at 5V. Please ensure your power supply can handle this current draw, especially if powering multiple sensors.
Q: Can this detect carbon monoxide specifically?
A: The MQ-135 is sensitive to a broad range of gases including CO, ammonia, and benzene. It is not specific to Carbon Monoxide alone; for dedicated CO detection, an MQ-7 sensor is recommended.
Household Water Dispenser Stand - Multi-Tier Floor Rack for Bottled Pure Water and Mineral Water in Offices
$129.74
WYPALL* Microfiber Cleaning Cloths Yellow 83610, 6 Sheets/Pack * 4 Packs/Case
$132.76
Ceramic Ink Dish, Water Dish, Brush Rest, Ice-Crack Ink Box, Multi-Function Brush Washer, Ink Stone, Brush Holder, and Kung Fu Tea Cup
$1.90
Car Tire Stone Removal Hook, Foldable and Extendable Tool for Extracting Pebbles from Treads
$2.07
Touchscreen Waterproof Phone Pouch for Swimming and Rafting, Sealed Bag for Beach, Sand, Snorkeling, and Underwater Photography
$5.53
Chunfei Grocery Store Yunan GR02 Gravel Bike, Thru-Axle, Mechanical Disc Brakes, Lightweight Touring Setup with Multiple Rack Mounts
$6,441.00
Electric Guitar Tutorial for Beginners - 7-Week Self-Study Plan with Exercises, Corrections, and Materials
$219.00
Professional Bathtub-Style Brush Washing Set - Cute 3-Piece Watercolor and Chinese Painting Brush Cleaner with Palette
$11.80
![[Sold Out & Discontinued - Display Only] Radish Defense ABO20.0 Spring Tour Series Blind Box Figure](https://www.gosteppe.com/cache/small/product/269201/legacy-main-5af4651a8d30dc42d9412600.png)
[Sold Out & Discontinued - Display Only] Radish Defense ABO20.0 Spring Tour Series Blind Box Figure
$16.90
Ebru Marbling Plastic Tool Kit – Needles, 3-Prong Combs, Cones, Straws, and Droppers for Peacock Patterns
$1.28
CANDLE.LAB | Silicone Border Mat for DIY Scented Candles and Soap Making Tray Mold
$32.00
Shiji Runde Coal Shed Mine Dust Removal Explosion-Proof Anti-Freezing Fog Cannon Port Dust Suppression 80m Ultra-Fine Industrial Fog Machine
$4,180.00
Mobile Retractable Spray Booth for Furniture - Foldable Track-Mounted Painting Room
$6,240.00
Long Handle Bristle Paint Brush - Hog Hair Brush for Oil Painting, Acrylic Wall Art, and Children's Drawing
$1.80
Electrostatic Powder Coating Equipment and Electronic Powder Dispenser Supply
$17,250.00
DIY Toast-Shaped Silicone Mold for Handmade Soap - Square Soap Making Mold
$105.00
Kindergarten Sponge Stamp Set – Mushroom-Head Circular Printing Tools for Kids' DIY Art and Painting Kits
$3.50
Heavy-Duty Lifting Chain Set – Manganese Steel Chains with Hooks, Rings, and Hoist Accessories
$198.00
Car Tire Stone Removal Tool, Multi-Function Groove Hook for Portable Tire Picking and Cleaning
$11.50
m Dogs Strap Auto Retractable Dual Dog Leash With
$199.92
Traditional Wooden Sheepskin Rattle Toy – Safe for Teething Newborns, Handcrafted Baby Bell Shaker
$17.80
Soilless Cultivation Equipment Plant Factory Display Rooftop Hydroponic Pipe System for Leafy Vegetables and Fruits, Type A Planting Rack
$2,620.16
Premium Ceramic Tea Canister and Gift Box Set - Empty Packaging for Black Tea, Pu'er, White Tea, and Biluochun
$121.00
Posture-Correcting Hole-Grip Pencils for Grade 1 - Triangular Barrel, Break-Resistant, Non-Toxic HB for Daily Writing and 2B for Exams
$3.02
Genuine OEM AC Blower Motor Heater Fan for Buick Excelle GT, Cavalier, and Monza
$255.00
TA1 TA2 Titanium Capillary Tubes - Small Diameter Titanium Pipes - GR5 Titanium Alloy Tubes
$240.00
Industrial Spray Painting Wipe Cloth Auto Bake Finish Film Application Degreasing Cloth Non-Woven Absorbent Paper Lint-Free Paper Electrostatic Dust Removal Paper
$75.66
US Standard Buttress Thread Inserts 22ER 16ER 11NR 16 10 12 8ABUT Internal 7 External 45 Degree
$43.20
Coating Workshop Cleaning Rags GAE Industry White Scrap Cloth Nylon Machine Cloth Blocks Industrial Glue Removal Furniture Cleaning
$96.31
Natural 8A Yellow Tiger Eye Loose Beads - Round Cat's Eye Bracelet for DIY Jewelry Making
$17.28
![[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)
