MQ2 gas sensor belongs to the MQ sensor family series designated for the detection and identification of flammable and combustible gases. The module can detect flammable gas in the range of 300 – 10000ppm. Its most common application is in the field of domestic gas leakage alarms and detectors with a high sensitivity to propane and smoke. The sensing material is SNO₂ for which the conductivity is lower in clean environments and higher when smoke or flammable gas is present. A simple circuit makes measuring this change in conductivity and turning it into data fairly straightforward, but does require some calibration.
MQ2 gas sensor has a high sensitivity to propane and smoke, and also can detect natural gas and other flammable steam well. It is low cost and is suitable for all kinds of different applications for detecting various flammable gases. MQ2 Gas sensors can detect or measure gasses like LPG, Alcohol, Propane, Hydrogen, CO, and even methane. The module version of this sensor comes with a Digital Pin which makes this sensor operate even without a microcontroller and that comes in handy when you are only trying to detect one particular gas.

MQ2 Gas Sensor Key Features
- Preheat duration 20 seconds
- Can be used to measure or detect LPG, Alcohol, Propane, Hydrogen, CO, and even methane
- Can be used as a Digital or analog sensor
- The Sensitivity of a Digital pin can be varied using the potentiometer
MQ2 Gas Sensor Pinout

Pin Name | Pin No. | Description |
---|---|---|
Vcc | 1 | This pin powers the module, typically the operating voltage is +5V |
GND | 2 | Used to connect the module to the system ground |
Digital Out | 3 | You can also use this sensor to get digital output from this pin, by setting a threshold value using the potentiometer |
Analog Out | 4 | This pin outputs 0-5V analog voltage based on the intensity of the gas |
Specifications
- Power Supply: 4.5V to 5V DC
- High sensitivity to Propane, Smoke, LPG, and Butane
- Wide range high sensitivity to Combustible gases
- Long life and low cost
- Analog and Digital output available
- Onboard visual indicator (LED) for indicating alarm
- Compact design and easily mountable
- Simple 4 PIN header interface
- The Drive circuit is simple.
- Sensor Type: Semiconductor
- Concentration : 300-10000ppm ( Combustible gas)
- Supply voltage =5v
Applications
- Combustible gas alarms
- Smoke Detectors
Datasheet
You can download the datasheet for MQ2 Combustible Gas Sensor Module by clicking the link given below:
See Also: CD4059 Program Divide-by-N Counter | ADXL335 Accelerometer Sensor Module | FC-28 Soil Moisture Sensor Module