A
Anonymous
Feb 20, 2026
Rating: 5/5
Arduino Compatible
Easy to wire up. Analog readings are stable once the sensor is heated properly.
Description
Smoke Sensor Module MQ-2/3/4/5/6/7/8/9/131/135/136/137/138/139 for Alcohol Detection
Reviews
Attributes
| Brand | - |
| Category | Electronic Components / Maker DIY / Computer Hardware, Monitors & Peripherals |
| Origin | - |
| Sensor Series | MQ-Series (MQ-2 to MQ-139) |
| Operating Voltage | 5V DC |
| Output Signal | Digital Switch Output (TTL) & Analog Output |
| Preheat Time | 24-48 Hours (Initial Burn-in) |
| Detection Target | LPG, Alcohol, Hydrogen, Methane, Smoke (Model Dependent) |
| Operating Temperature | -10°C to 50°C |
| PCB Dimensions | 32mm x 20mm x 22mm |
| Comparator Chip | LM393 Wide Voltage Comparator |
| Sensitivity Control | Adjustable via Onboard Potentiometer |
| Interface Pins | 4-Pin Header (VCC, GND, DO, AO) |
5 reviews
A
Anonymous
Jan 28, 2026
Rating: 3/5
Long Warmup Period
Didn't work right out of the box. Needs 24h power cycle as stated in specs. Works now though.
A
Anonymous
Jan 26, 2026
Rating: 5/5
Great Variety Pack
Bought multiple types for different gas detection tests. All function correctly as expected.
A
Anonymous
Jan 26, 2026
Rating: 4/5
Good Quality
Solid build quality. Remember these are not certified for home safety systems, but great for learning.
A
Anonymous
Jan 20, 2026
Rating: 5/5
Perfect for Prototyping
Used the MQ-2 for a school project. Detects smoke well after warmup. Easy to interface with Arduino.
5 FAQ
Q: Does it support 3.3V microcontrollers?
A: Yes, logic levels are compatible, but the sensor heater requires 5V for optimal performance.
Q: Can I use this for a home smoke alarm system?
A: No, these modules are for educational and prototyping use only. Please use certified devices for life safety.
Q: What is the exact pinout configuration?
A: The 4 pins are VCC (Power), GND (Ground), DO (Digital Out), and AO (Analog Out).
Q: How do I adjust the sensitivity threshold?
A: Use the blue potentiometer on the board with a small screwdriver to adjust the digital output threshold.
Q: Which sensor model detects alcohol specifically?
A: The MQ-3 model is designed specifically for alcohol and ethanol detection.
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