Description
Reviews
| Brand | - |
| Category | Robotics / STEM Teaching Tools / Sensors |
| Origin | - |
| Model Number | MQ-3 |
| Detection Gas | Alcohol, Ethanol, Methane |
| Operating Voltage | 5V DC |
| Output Type | Digital (DO) and Analog (AO) |
| Heating Voltage | 5.0V ± 0.2V |
| Load Resistance | 200kΩ |
| Heater Resistance | 33Ω ± 10% |
| Sensing Range | 0.04mg/L to 4mg/L |
| Response Time | < 10 seconds |
| Board Dimensions | 32mm x 20mm x 14mm |
Anonymous
Mar 30, 2026
Rating: 5/5
Great starter sensor
As someone new to electronics, I found this easy to wire up. Plenty of tutorials online helped me get the code running. It lights up the LED immediately when exposed to hand sanitizer vapor.
Anonymous
Mar 15, 2026
Rating: 3/5
Works but gets hot
The sensor detects alcohol as advertised, but the heating element gets quite hot during operation. Make sure your enclosure has ventilation. Otherwise, it functions correctly for basic detection tasks.
Anonymous
Mar 14, 2026
Rating: 5/5
Reliable and Affordable
I bought three of these for a breathalyzer prototype. All three performed consistently. The digital output threshold is adjustable via the potentiometer, which is a nice feature.
Anonymous
Mar 13, 2026
Rating: 4/5
Good sensitivity, needs calibration
The module arrived quickly and looks well-soldered. It does require some time to heat up before giving accurate readings, which is normal for this type of sensor. Once calibrated, it performs well.
Anonymous
Mar 08, 2026
Rating: 5/5
Perfect for Arduino Projects
This sensor works flawlessly with my Arduino Uno. The analog output is stable after the initial warm-up period, and detecting alcohol vapor is very responsive. Great value for hobbyists.
Anonymous
Mar 01, 2026
Rating: 4/5
Solid performance for the price
No complaints here. It's a standard MQ-3 module. The pins are clearly labeled, and the PCB quality seems decent. Just remember it consumes more power than typical logic sensors due to the heater.
Q: How long does it take for the sensor to warm up?
A: Typically, MQ series gas sensors require a preheat time of about 24 to 48 hours for stable long-term usage, but for basic testing, you will see reactive results within 1 to 2 minutes of powering on.
Q: Does this module work with 3.3V microcontrollers like ESP32?
A: The sensor heater requires 5V to operate correctly. While the logic output might work with 3.3V, we recommend powering the VCC pin with 5V and using a voltage divider or level shifter for the signal pins if connecting to a 3.3V MCU.
Q: What is the purpose of the blue potentiometer on the board?
A: The blue potentiometer adjusts the sensitivity threshold for the Digital Output (DO). Turning it changes the point at which the DO LED turns on and the signal pin goes low/high.
Q: Is there a library available for this sensor?
A: Since this is an analog/digital hardware sensor, it doesn't need a specific driver library. You simply read the analog value using the standard 'analogRead()' function in Arduino or similar commands in other platforms.
Q: Can this detect cigarette smoke?
A: While it may react slightly to smoke, the MQ-3 is specifically tuned for alcohol and ethanol. For smoke detection, we recommend the MQ-2 or MQ-7 sensors which are optimized for combustible gases and smoke.
Storage Bag Compatible with Dyson/Laifen Hair Dryer Curling Iron Straightener Double-Layer Portable Travel Hand-Carry Case
$48.40
Chushinmi - Silicone Collapsible Dish Drying Rack, Kitchen Organizer, Sink Utensil Holder for Bowls and Chopsticks
$61.90
Wenxin Tang Ultra-Clear Zhi Yong Thousand Character Classic Regular Script Calligraphy Cards - Boxed Practice Sheets for Medium-Sized Brush Writing
$40.80
Cute Pig Pot Lid Holder and Drainage Mat, Multi-Function Heat Insulator and Cutting Board Rest
$2.01
![[Damai Micro-Needle Hair Transplant Patent] Top Scalp Thinning Treatment | High-Density 200 Grafts Micro-Needle Transplant](https://www.gosteppe.com/cache/small/product/269847/legacy-main-921c5365abd34b2597668ec5.webp)
[Damai Micro-Needle Hair Transplant Patent] Top Scalp Thinning Treatment | High-Density 200 Grafts Micro-Needle Transplant
$199.00
Song Dynasty Guo Xi's 'Traveling in Snowy Mountains' Hanging Scroll - Study Copy Template, Art Core, Landscape Painting, Zen Decorative Art, HD Collectible
$12.80
Drain Basket for Wet/Dry Separation with Hanging Vegetable Strainer Rack
$111,978.00
Custom Mesh Lid Organizer Bag for Pelican 1535 Case - Laptop Compartment
$118.70
Home LED High-Power Rechargeable Flashlight, Multi-Purpose Long-Range Portable Ultra-Bright Mini Torch
$20.60
Accsoon CineEye M7 Pro 4K Wireless Video Transmitter and Monitor with 7-inch HDMI/SDI Dual-Transmission Screen
$99.00
Stainless Steel Sink Rack Kitchen Organizer Over-Sink Dish Drying Rack with Utensil Holder
$48.00
Specialized Vegetable Growing Box - Foam Balcony Planter, Rectangular Plastic Pot for Home Gardening
$41.70
Thickened Resin Vegetable Planter Box - Rectangular Plastic Balcony Pot for Growing Vegetables and Flowers
$101.00
SEATOSUMMIT Outdoor Travel Portable Waterproof First Aid Kit Wilderness Survival Personal Medical Folding Storage Bag
$79.00
Commercial Gas Storage Water Heater, Condensing Low-NOx Boiler, Fully Automatic Natural Gas Hot Water Furnace for Hotels
$13,175.00
SH1.0/1.25/ZH1.5/PH2.0XH2.54 Electronic Wire Connector Terminal Cable 2P-12P
$0.04
VFD Capacitor ALS30A1363KJ/ALS30C1024NP/ALS30C1023NP
$500.00
200X18DNNmm L Shape Stainless Stel Corern Brace Repeair Ang
$88.28
Quilling Paper Set Gradient Color Tool Kit Handmade Quilling Strips Basic Packaging for Fine Line Coloring
$38.00
Standard Ou Kai Calligraphy Beginner's Sun Tzu's Art of War & Thirty-Six Stratagems Small Regular Script Brush Copybook Xuan Paper Long Scroll for Tracing
$18.00
Mold Release Oil for Incense Beads and Tags - Colorless, Odorless, Food-Grade Auxiliary Release Agent
$8.00
Tafara Aromatherapy Matches - Premium Extended-Length Safety Matches for Incense Burners (20 Count)
$23.80
Magnetic Sponge Holder and Steel Wool Rack for Sink, Stainless Steel No-Drill Kitchen Organizer
$9.94
Touchmark Square Sketchbook for Acrylic Markers - Thick Paper Art Journal for Quick-Dry, Smudge-Free Drawing
$10.80
Mo Hao Detail Brush Set, Goat Hair Liner, Wolf Hair Round/Flat Brushes for Oil Painting, Art & Gouache
$78.00
Authentic Military-style Socks for Men - Summer and Winter Anti-odor Sweat-absorbing Mid-calf Black and Navy Blue Training and Sports Socks
$23.80
Alliance Authorized Plaque - Yoga Alliance RYT, Pilates Alliance, International Yoga Alliance, China Yoga Alliance
$380.00
Xiupu Fraycolor Marker Airbrush Kit for Figure Model Painting Portable Rechargeable Airbrush and Pump Set
$127.00
Caoyige Thickened Felt Calligraphy Mat with Bound Edges - Ideal for Students and Beginners Practicing Brush Writing
$4.93
Colored Paper Signing Board CP Autograph Panel Japanese Anime Drawing Paper Watercolor Paper Square Blank Signature Card for Markers Anime OC Hand-Drawn Cards
$10.80
![[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)
