Description
Reviews
| Brand | - |
| Category | Robotics / STEM Teaching Tools / Sensors |
| Origin | - |
| Model Number | MQ-2-135-3-7-9 |
| Sensor Type | Semiconductor Gas Sensor |
| Detectable Gases | LPG, Propane, Hydrogen, Alcohol, Smoke, CO |
| Operating Voltage | 5V DC |
| Heater Voltage | 5V ± 0.2V |
| Load Resistance | 20kΩ (Adjustable) |
| Heater Resistance | 33Ω ± 5% |
| Response Time | < 10 seconds |
| Recovery Time | < 30 seconds |
| Operating Temperature | -10°C to 50°C |
Anonymous
Mar 29, 2026
Rating: 5/5
Perfect for my Arduino safety project
This sensor module works exactly as described. I connected it to my Arduino Uno to detect smoke and LPG in my workshop. The analog output is stable, and the sensitivity potentiometer makes calibration very easy. Great value for the price.
Anonymous
Mar 25, 2026
Rating: 4/5
Solid performance for the cost
Does what it says on the tin. It's not an industrial-grade calibrated instrument, but for hobbyist home automation alerts, it is more than sufficient. The LED indicator is a nice touch for visual feedback.
Anonymous
Mar 18, 2026
Rating: 5/5
Fast shipping and works great
Arrived well-packaged. Tested it against some isopropyl alcohol and smoke from incense; the voltage output spiked immediately. Very sensitive and responsive. Will buy more for other rooms.
Anonymous
Mar 15, 2026
Rating: 5/5
Reliable combustible gas detection
I've used several MQ series sensors, and this one is consistent. It reacts quickly to butane from a lighter and cigarette smoke. The digital output pin is also handy for setting a simple threshold without complex coding.
Anonymous
Mar 09, 2026
Rating: 5/5
Great for university projects
Bought this for our final year air quality monitoring system. It integrates easily with Raspberry Pi and ESP32 boards. Documentation online is plentiful, which helped us get started quickly. Highly recommended for students.
Anonymous
Mar 07, 2026
Rating: 4/5
Good sensor, needs warm-up time
The build quality is solid and the pins are well-soldered. Just remember that these MQ sensors need about 24-48 hours of initial burn-in for best stability, though it works reasonably well immediately. Detected alcohol vapors instantly during testing.
Q: What is the power consumption of the heater?
A: The heater operates at 5V with a resistance of approximately 33 ohms, drawing roughly 150mA. Please ensure your microcontroller or power supply can handle this current, as it is too high to be powered directly from a standard GPIO pin.
Q: Can this sensor distinguish between different types of gases?
A: The MQ-2 sensor is sensitive to a range of combustible gases and smoke, but it cannot specifically distinguish between them on its own. It provides a general concentration level. For specific gas identification, you would need an array of different sensors and pattern recognition algorithms.
Q: How long does the sensor last before needing replacement?
A: Under normal operating conditions, the typical lifespan of the sensing element is about 2 years. However, exposure to extremely high concentrations of gas or corrosive environments can shorten this life. Regular calibration checks are recommended.
Q: Does this come with a library for Arduino?
A: This is a hardware module and does not include software. However, there are many open-source libraries available in the Arduino Library Manager (search for 'MQUnifiedsensor' or similar) that make reading and calibrating this sensor very easy.
Q: Is this module compatible with 3.3V logic systems like ESP8266?
A: Yes, the analog output signal is generally compatible, but the module is designed for 5V operation. For best results, power the module with 5V and connect the signal output to your 3.3V board. If the output voltage exceeds your board's limit, a voltage divider may be required.
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