Attributes

Brand	-
Category	Robotics / STEM Teaching Tools / Sensors
Origin	-
Model Compatibility	MQ-2, MQ-3, MQ-4, MQ-5, MQ-6, MQ-7, MQ-8, MQ-9, MQ-131, MQ-135, MQ-136, MQ-137, MQ-138, MQ-139
Operating Voltage	5V DC
Output Signal	Digital Switch Output (0 and 1) and Analog Voltage Output
Detection Range	Alcohol, LPG, i-Butane, Propane, Methane, Hydrogen, Smoke
Sensitivity Adjustment	Adjustable via onboard potentiometer
Interface Type	3-Pin Pin Header (VCC, GND, OUT)
PCB Dimensions	32mm x 20mm x 15mm
Heater Resistance	Approx. 33Ω ±5% at room temperature
Load Resistance	Adjustable
Application	Arduino, Raspberry Pi, DIY Gas Leak Detectors, Safety Monitoring Systems

6 reviews

Anonymous

Mar 28, 2026

Rating: 4/5

Good sensor, needs warm-up time

The module works well for detecting alcohol vapors in my fermentation monitoring setup. Just remember it needs about 24-48 hours of initial burn-in for best stability, as stated in the datasheet.

Anonymous

Mar 21, 2026

Rating: 5/5

Perfect for my home safety project

I used the MQ-2 variant for a smoke detection prototype. The analog output is very stable, and the digital threshold is easy to set with the screw. Works flawlessly with my Arduino Uno.

Anonymous

Mar 12, 2026

Rating: 4/5

Easy to interface

Very straightforward to connect. The documentation online is plentiful. Only giving 4 stars because the header pins were slightly bent upon arrival, but easy to fix.

Anonymous

Mar 11, 2026

Rating: 5/5

Great value for money

Bought a pack of these for a university project on air quality. The build quality is solid, and the pins are well-soldered. Highly recommend for students and hobbyists.

Anonymous

Mar 09, 2026

Rating: 5/5

Reliable gas detection

Integrated this into a smart home system to monitor natural gas levels. The response time is quick, and the sensitivity adjustment allows me to fine-tune it for my specific environment.

Anonymous

Mar 07, 2026

Rating: 5/5

Excellent for ventilation control

Using the MQ-135 version to monitor CO2 and ammonia levels in my greenhouse. It triggers my exhaust fans perfectly when levels rise. Very satisfied with the performance.

5 FAQ

Q: Can I use this to detect carbon monoxide specifically?

A: The MQ-7 variant in this product line is specifically designed for Carbon Monoxide (CO) detection. Please ensure you select or configure the MQ-7 element if CO is your primary target.

Q: How long does the sensor need to heat up before giving accurate readings?

A: While it starts responding quickly, for maximum stability and accuracy, we recommend a pre-heat time of 24 to 48 hours for new sensors. After that, a few minutes of warm-up before each use is sufficient.

Q: Does this module work with 3.3V logic boards like ESP32?

A: Yes, the digital output can work with 3.3V systems, but the sensor heater requires 5V. Ensure you power the VCC pin with 5V while connecting the OUT pin to your 3.3V microcontroller input.

Q: Which specific model should I choose for detecting cigarette smoke?

A: For cigarette smoke and general combustible gases, the MQ-2 model included in this series is the most appropriate choice due to its high sensitivity to smoke and LPG.

Q: Is the analog output linear with gas concentration?

A: The output voltage changes with gas concentration, but the relationship is generally logarithmic rather than strictly linear. Calibration with known gas concentrations is recommended for precise measurements.

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