Attributes

Brand	-
Category	Robotics / STEM Teaching Tools / Sensors
Origin	-
Model Number	MQ-2/135/3/7/9
Detection Gases	Smoke, Alcohol, Hydrogen, CO, LPG, Propane
Operating Voltage	5V DC
Interface Type	Analog and Digital Output
Heater Voltage	5.0V ± 0.2V
Load Resistance	Adjustable via Potentiometer
Preheat Time	24-48 Hours
Working Temperature	-10°C to 50°C
Humidity Range	Less than 95% RH
Compatibility	Arduino, Raspberry Pi, STM32

6 reviews

Anonymous

Mar 23, 2026

Rating: 5/5

Works well in automation setups

Integrated this into my greenhouse monitoring system to detect any faulty heating equipment. It has been running for two months without issues. The sensitivity to carbon monoxide is a great feature.

Anonymous

Mar 14, 2026

Rating: 4/5

Great for learning embedded systems

Excellent component for students and makers. The documentation online is plentiful. My only minor complaint is that the pins are a bit close together, so careful soldering is required if you want to add headers.

Anonymous

Mar 12, 2026

Rating: 5/5

Reliable gas detection

I used this for a prototype gas leak detector. The digital output threshold is easily adjustable with the onboard potentiometer. It triggered my alarm system reliably during testing with lighter fluid vapor.

Anonymous

Mar 11, 2026

Rating: 5/5

Perfect for my home safety project

This sensor module works exactly as described. I connected it to my Arduino Uno and was able to detect smoke and alcohol vapors within minutes after the preheat cycle. The analog output is stable and easy to calibrate.

Anonymous

Mar 11, 2026

Rating: 4/5

Good value but needs patience

The sensor is sensitive and responsive. Just remember that it requires a long preheat time (about 24 hours) before giving accurate readings. Once warmed up, it detects combustible gases very well.

Anonymous

Mar 09, 2026

Rating: 3/5

Decent but power hungry

The sensor functions correctly, but the internal heater draws quite a bit of current. Make sure your power supply can handle at least 150mA continuously. Otherwise, it performs as expected for the price.

5 FAQ

Q: Can this detect natural gas leaks specifically?

A: Yes, the MQ-2 sensor is sensitive to liquefied petroleum gas (LPG), propane, and methane, which are common components of natural gas.

Q: How do I adjust the sensitivity threshold?

A: There is a blue potentiometer on the board. Turn it clockwise to increase sensitivity (lower threshold) or counter-clockwise to decrease sensitivity.

Q: What is the recommended preheat time before first use?

A: We recommend a preheat time of 24 to 48 hours for the sensor to stabilize and provide accurate baseline readings.

Q: Does this module come with header pins soldered?

A: No, the module typically comes without header pins soldered to allow for flexible mounting options. You will need to solder them yourself if required.

Q: Is the output signal 3.3V or 5V compatible?

A: The module operates on 5V. While the analog output can be read by 3.3V microcontrollers, ensure the voltage levels are compatible or use a voltage divider to protect 3.3V logic inputs.

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