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) |
| Preheat Time | 24-48 Hours |
| Load Resistance | 20kΩ (Adjustable) |
| Heater Resistance | 33Ω ± 5% |
| Heater Current | < 150mA |
| Interface Type | 3-Pin Header (VCC, GND, OUT) |
| Compatible Boards | Arduino, Raspberry Pi, ESP32, STM32 |
Anonymous
Mar 29, 2026
Rating: 4/5
Sensitive and responsive
It picks up even slight changes in air quality. I tested it with a lighter and it reacted instantly. Deducting one star only because the pins were slightly bent on arrival, but easy to fix.
Anonymous
Mar 28, 2026
Rating: 5/5
Solid hardware
The PCB looks clean and the soldering is good. No issues with noise in the analog signal. Highly recommend for anyone building IoT air quality nodes.
Anonymous
Mar 26, 2026
Rating: 5/5
Reliable gas detection
I use this in my workshop to detect fumes. The digital output triggers my exhaust fan reliably when gas levels rise. Very satisfied with the purchase.
Anonymous
Mar 13, 2026
Rating: 4/5
Good value but needs patience
The module is well-built and the potentiometer allows for easy threshold adjustment. Just remember it needs at least 24 hours of preheating before accurate readings can be taken.
Anonymous
Mar 10, 2026
Rating: 5/5
Great for university projects
Bought this for a final year environmental monitoring project. Documentation online is plentiful, and the sensor integrates easily with standard libraries.
Anonymous
Mar 10, 2026
Rating: 5/5
Perfect for my home air monitor project
This sensor works exactly as described. I connected it to an Arduino Uno and had readings within minutes after the initial burn-in period. Great sensitivity to smoke and alcohol vapors.
Q: Is the output voltage 3.3V or 5V compatible?
A: The module operates on 5V. The digital output is TTL compatible (0-5V). If using with a 3.3V microcontroller like ESP32, a voltage divider may be needed for the signal pin.
Q: Does this module come with the heating element pre-installed?
A: Yes, the MQ-135 sensing element and heater are fully assembled on the PCB. You only need to connect power and signal wires.
Q: How do I adjust the sensitivity threshold?
A: There is a blue potentiometer on the board. Rotate it clockwise to increase sensitivity (lower threshold) or counter-clockwise to decrease it. Use a multimeter or LED test to verify.
Q: What is the warm-up time required before calibration?
A: We recommend a preheat time of 24 to 48 hours for the first use to stabilize the internal heater and ensure accurate baseline readings.
Q: Can this sensor detect Carbon Monoxide (CO) specifically?
A: The MQ-135 is sensitive to a broad range of gases including CO, but it is not specific to CO alone. For dedicated CO detection, an MQ-7 sensor is recommended.
Selected Factory Low-Temperature 3D Printing Pen for Kids, Children's 3D Printing Pen Set, 3D Drawing Pen
$100.02
Milk Pasteurization Line - Small-Scale Yogurt Production Machine for Liquid Yogurt and Pasteurized Milk
$8,148.00
Commercial Small Heating Warmer Cabinet, Glass Constant-Temperature Countertop Display Case for Egg Tarts, Burgers, and Fried Chicken
$884.00
Custom Seal Stamp Engraving Personal Name Phone Number Private Chop
$5.89
Commercial Food Warmer Cabinet for Milk, Soy Milk, Burgers, Egg Tarts, Fried Chicken, Pies, Youtiao, and Bread Display
$1,355.00
PJ0040 Rose Embossed Cross Silicone Mold - For Candles, Aromatherapy, Soap, Plaster, and DIY Crafts
$11.20
Yuwell Oxygen Concentrator Control Board Motherboard 8F-3AW/8F-5AW/9F-5BW
$120.00
Leyingfang Floating Pen for Kids and Students - Water-Based Non-Toxic Erasable Whiteboard Pen for Drawing in Water, Large Capacity Suspension Pen
$18.00
Car Wheel Lug Nut Covers - Colorful Silicone Dust-Proof and Rust-Proof Caps for Tire Bolt Protection and Exterior Styling
$8.80
Automatic Stainless Steel Vegetable Slicer for Ginger, Potatoes, Carrots, Onions, and Cabbage - Commercial Dicing Machine
$3,951.36
![[Damai Holds Micro-Needle Hair Transplant Patent] Top Thinning Hair Transplant | Micro-Needle Density Enhancement (500 Units)](https://www.gosteppe.com/cache/small/product/270156/legacy-main-525bdaff56f89ee94752ef9c.webp)
[Damai Holds Micro-Needle Hair Transplant Patent] Top Thinning Hair Transplant | Micro-Needle Density Enhancement (500 Units)
$7,000.00
Little Leather Paper Strip Music Box (30-Note) Sheet Music - Contact Before Ordering; Specify Song Email for Digital Score Delivery
$1.00
Kitchen Sink Strainer Basket Push-Type Food Residue Separator Filter Hanging Storage Rack
$3.80
Heavy-Duty Heat-Treated CV Joint Puller Tool - Axle Ball Cage Removal and Installation Device for Automotive Repair
$66.00
Mobile Integrated Waste Transfer Station - 17 Cubic Meters Movable Compression Container
$159,443.00
Antique Glaze White Ceramic Brush Washer Large Brush Washer Water Pot Ink Stone Washing Calligraphy Painting Brush Washing Basin Four Treasures of the Study
$16.80
Authentic Chinese Philosophy Classics: Di Tian Sui, Qiong Tong Bao Jian, San Ming Tong Hui - Annotated & Illustrated Edition
$29.90
Household Disposable Kitchen Sink Garbage Filter Mesh Drain Pool Dishwashing Basin Strainer Vegetable Bowl Leftover Sink
$3.51
Continental Run-Flat Tires: 225/235/245/255/265 45/50/55 R17/R18/R19/R20/R21/R22
$357.00
Foldable Steel Tire Stone Removal Hook - Multi-Tool for Tire Repair, Stone Picking, and Emergency Window Breaking with Storage Bag
$11.70
Integrated Catalytic Combustion Unit RCO Furnace - Exhaust Gas Treatment System with Activated Carbon Adsorption-Desorption and Catalytic Combustion
$231,249.00
Universal Waterproof and Sunproof Cover for E-Bike Charger with Outdoor Storage Box
$11.85
Baohong Paper Brick Watercolor Paper Pad, Medium/Coarse Texture, Square/Round Shapes for Painting, Sketching, and Cotton Pulp Practice
$28.00
Commercial Food Warmer Cabinet for Pies, Youtiao, Burgers, Egg Tarts, and Fried Chicken, Heating and Temperature-Controlled Display Case
$977.00
Masking Tape Spray Paint Shielding Paper for Art Students and Sketching - Non-bleeding, Residue-free, Hand-tearable, Shoe-safe
$1.00
Electric Scooter and Motorcycle Hook - Multi-Functional Storage Hanger for Delivery Bikes and Cargo Boxes
$2.50
Huirui 420AB Fast-Drying Glue for Silicone - Bonds ABS, Stainless Steel, TPE, Rubber; High-Strength Instant Adhesive for Difficult Materials
$36.00
Color Proofing Instrument Ink Mixing Tool Sample Making Machine
$1,860.00
Variable Frequency Drive 0.75kW 2.6A Three-Phase 380V
$1,430.00
2026 Spring PEP New Edition Primary English Grade 3 Volume 2 Four-Line Three-Grid Word Cards for Teachers, Open Class Competition Creative Blackboard Design, Teaching Contest Blackboard Strips and Teaching Aids
$11.30
![[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)
