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-135
Detection Gases	LPG, Propane, Hydrogen, Alcohol, Smoke, CO, Methane
Operating Voltage	5V DC
Output Signal	Digital Switch Output (0 and 1) & Analog Voltage Output
Indicator LED	Power LED and Digital Switching Output LED
Sensitivity Adjustment	Adjustable via onboard potentiometer
PCB Dimensions	32mm x 20mm x 14mm
Mounting Holes	4 x 3mm diameter holes for easy installation
Interface Type	3-pin connector (VCC, GND, OUT) compatible with Arduino and Raspberry Pi
Preheat Time	Approximately 24-48 hours for stable readings upon first use

6 reviews

Anonymous

Mar 30, 2026

Rating: 4/5

Works as described for alcohol detection

Using the MQ-3 model to monitor fermentation levels in a home brewing setup. It detects ethanol vapor accurately. Just ensure you have a proper 5V power supply to avoid noise in the signal.

Anonymous

Mar 20, 2026

Rating: 5/5

Reliable and robust

These modules are sturdy and the pin headers are well-soldered. I've integrated the MQ-135 for air quality monitoring in several smart home prototypes without any failures so far.

Anonymous

Mar 12, 2026

Rating: 3/5

Decent but needs external circuitry for precision

For basic detection, this is fine. However, if you need precise PPM measurements, you will need to do significant calibration and possibly add external filtering. Good for binary 'safe/unsafe' alerts though.

Anonymous

Mar 10, 2026

Rating: 5/5

Perfect for my home safety project

I used the MQ-2 variant to build a custom smoke detector for my workshop. The analog output is very responsive, and calibration was straightforward using the potentiometer. Highly recommended for DIY electronics enthusiasts.

Anonymous

Mar 08, 2026

Rating: 4/5

Good value, requires patience

The sensor works well once it has been burned in for the recommended 24 hours. Initially, the readings were fluctuating, but they stabilized nicely. Great price point for prototyping gas detection systems.

Anonymous

Mar 05, 2026

Rating: 5/5

Excellent for student projects

Bought a bulk pack for our university robotics club. Students found them easy to interface with Arduino boards. The digital output threshold adjustment is a great feature for teaching sensor logic.

5 FAQ

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

A: For initial use, the sensor should be powered on for 24 to 48 hours to burn in the heating element and stabilize the baseline. After the initial burn-in, a warm-up time of 1-3 minutes is usually sufficient for subsequent uses.

Q: Is this sensor suitable for detecting natural gas leaks in a residential setting?

A: This module is designed for educational and prototyping purposes. While it can detect combustible gases like methane, it is not certified for life-safety applications or permanent residential installation. Please use certified commercial detectors for actual home safety.

Q: What is the difference between the analog and digital output pins?

A: The Analog Output (AO) provides a voltage proportional to the gas concentration, allowing you to read varying levels. The Digital Output (DO) acts as a switch that goes high or low when the gas concentration exceeds the threshold set by the onboard potentiometer.

Q: Can this module be powered directly by a 3.3V Raspberry Pi GPIO pin?

A: While the logic output may work, the sensor heater element typically requires 5V for proper operation. We recommend powering the VCC pin with a dedicated 5V source and using a voltage divider or level shifter for the signal pin if connecting to 3.3V logic.

Q: Does this package include the specific sensor tube for MQ-135 or just the board?

A: The product listing covers multiple models. You will receive the specific module you select at checkout (e.g., if you choose MQ-135, you get the board with the MQ-135 tube pre-installed). The listing title indicates compatibility with all listed types depending on your selection.

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