A
Anonymous
Apr 01, 2026
Rating: 5/5
Great for students
Bought 10 for our lab. Easy to integrate into lessons.
Description
MQ-2-135-3-7-9 Smoke, Air, Alcohol, Hydrogen, and Carbon Monoxide Sensing Module
Reviews
Attributes
| Brand | - |
| Category | Electronic Components / Maker DIY / Computer Hardware, Monitors & Peripherals |
| Origin | - |
| Sensor Technology | Metal Oxide Semiconductor |
| Operating Voltage | 5V DC |
| Output Type | Analog & Digital TTL |
| Preheat Duration | 24 to 48 Hours |
| Operating Temperature | -10°C to 50°C |
| Storage Temperature | -20°C to 70°C |
| Humidity Range | Less than 95% RH |
| Board Size | 32mm x 20mm |
| Pin Configuration | 3-Pin Header (VCC, GND, OUT) |
| Recommended Use | Educational & Prototyping |
5 reviews
A
Anonymous
Mar 30, 2026
Rating: 3/5
Gets warm
Normal operation but noticed heat during prolonged use.
A
Anonymous
Mar 16, 2026
Rating: 5/5
Works well with Arduino
Tested with MQ-2, detects smoke reliably during my tests.
A
Anonymous
Feb 27, 2026
Rating: 5/5
Easy to interface
Digital output threshold is adjustable via potentiometer.
A
Anonymous
Feb 17, 2026
Rating: 4/5
Good value
Needs calibration but solid build quality for the price.
5 FAQ
Q: Which MQ model detects alcohol?
A: The MQ-3 model is specifically designed for alcohol vapor detection.
Q: Certified for home safety alarms?
A: No, this module is for prototyping only and not certified for life safety.
Q: Are libraries available?
A: Yes, many open-source libraries exist for Arduino and ESP32.
Q: Can I use 3.3V logic?
A: Power should be 5V for the heater, logic output can interface with 3.3V.
Q: Is it waterproof?
A: No, the sensor is not waterproof. Keep away from direct moisture.
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