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.
Portable Travel Art Set for Kids - Watercolor Paint Box with Sketchbook and Mini Drawing Board
$9.05
Pneumatic Fitting PU Straight Connector Quick-Insert Plastic High-Pressure Air Hose Fitting PU-4681012
$4.90
Chain Sling Lifting Shackle Steel Chain Single Leg with Hooks on Both Ends for Towing, 2m Length, 5 Ton Capacity
$79.00
Large Brush Set Supply - Watercolor Pen Set for Children's Day Painting, Art, and Coloring
$25.55
Non-Bleeding Liquid Candle Dye - Macaron Colors for Soy Wax DIY Aromatherapy Candles
$21.00
Alloy Wheel Lug Nut Caps Compatible with Buick Excelle, Verano, Regal, LaCrosse, Encore, Cruze, Malibu, and GL8
$3.40
![[Damai Holds Micro-Needle Hair Transplant Patent] AI Robot Precision Hair Transplant | 1000 Units Hairline Planting](https://www.gosteppe.com/cache/small/product/269438/legacy-main-d695e1be3b1b8212f24ac863.webp)
[Damai Holds Micro-Needle Hair Transplant Patent] AI Robot Precision Hair Transplant | 1000 Units Hairline Planting
$24,990.00
Premium Ceramic Tea Canister Packaging Box, Empty Gift Box for Black Tea, Pu'er, White Tea, Biluochun, Gift Set Empty Box
$104.95
Thickened 304 Stainless Steel Planter Box for Home Balcony Vegetable Gardening - Rectangular Large Flower Pot for Rooftop Planting
$204.00
Zhongheng Car Tire Stone Hook - Multi-Function Tire Cleaner Tool to Prevent Blowouts
$7.14
JoanMiro 3D Printing Pen for Kids, Low-Temperature 3D Stereoscopic Drawing Toy, Perfect Gift for Boys and Girls on Children's Day
$29.90
Stainless Steel Tire Stone Removal Hook - Multi-Function Car Tire Cleaning Tool for Picking and Scraping Stones
$5.03
Cart Cover Rice Husk Charcoal Premium Plant Ash Grain Shell Carbon Natural Organic Fertilizer for Vegetables Succulents and Flowers
$6.55
Aojilong Automotive Plastic Restorer – Revives Black Trim, Repairs Aging, Crystal Coating Finish
$28.80
Hotel Meat Warmer Lamp - Buffet Heating Light for Cafeterias and Restaurants
$5,989.00
Topmodel Children's Watercolor Coloring Book Set with Pens, Baby Graffiti Sketchbook, Fill-in Storybook 3073
$119.09
Children's Potty Training Seat for Boys and Girls, Toddler Toilet Trainer with Urinal Bucket
$17.90
265/70R17 AT Off-Road Tire, Also Available in 205/215/225/235/45/50/55/60R18/20 High-Performance Sizes for 19-inch Wheels
$898.00
CANDLE.LAB | Silver Metal and Wood Wick Centering Device - DIY Tool for Aromatherapy Container Candles
$2.50
Custom Solid Wood Plaque - Antique Style Wooden Storefront Sign, Door Plaque, Carved Wood Board with Arched Couplets
$50.00
Industrial Scouring Pads - Stainless Steel Brushing and Rust Removal for Iron Plates - Heavy-Duty Kitchen Cleaning and Polishing
$17.62
Supply Fully Automatic Self-Cleaning Filter Pipeline Backwash Filtration Machine Stainless Steel Scraper Filter
$9,600.00
Fangxinyue Scented Candle Glass Windshield - High Borosilicate Cover to Improve Memory Ring Burning
$29.90
Hanging Drainage Basket Kitchen Sink Strainer Plastic Storage Rack Food Waste Filter
$2.85
Over-Toilet Storage Cabinet with Doors - Multi-Tier Floor Standing Bathroom Organizer for Narrow Spaces
$258.00
Inth A6 Multifunctional Leather Journal - Vintage Sketchbook, Watercolor Pad, and Doodle Book with Replaceable Cotton Refill Pages for Students
$26.90
Beginner Chinese Painting Line Drawing Copybook: Animals, Flowers, Figures, and Landscapes
$18.80
vantkevin Scented Candle Tool Set for Extinguishing Flames and Snuffing Wicks
$17.60
Multi-Function Car Tire Stone Remover Tool - Hook Pick and Screwdriver for Tread Cleaning
$3.80
Pad Printing Machine Parts: Fixed Ink Roller Screw, Steel Plate Mounting Screw, Blade Holder Adjustment Nut, Blade Clamp Screw
$0.30
![[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)
