MQ-2 Smoke Sensor

The gas-sensing material used in the MQ-2 smoke sensor is tin dioxide (SnO2), which has a low conductivity in clean air. When there is flammable gas in the environment where the smoke sensor is located, the conductivity of the smoke sensor increases with the increase of the concentration of flammable gas in the air. The change in conductivity can be converted into an output signal corresponding to the gas concentration of this smoke sensor using a simple circuit.

The MQ-2 gas smoke sensor has high sensitivity to liquefied gas, propane, and hydrogen, and is also ideal for the detection of natural gas and other combustible vapors. This gas sensor can detect a variety of flammable gases and is a low-cost smoke sensor suitable for a variety of applications.


Related Products


Sensor Features
MQ-2 smoke sensor has good sensitivity to combustible gas in a wide concentration range

High sensitivity to liquefied gas, propane, hydrogen

Long life and low cost

A simple drive circuit can


main application
Household Gas Leak Alarm

Industrial flammable smoke gas alarms

Portable Smoke and Gas Detectors


Technical indicators

Product number

MQ-2 Smoke Sensor

product type

Semiconductor gas sensor

standard package

bakelite, metal cover

detect gas

flammable gas, smoke

Detection concentration

300-10000ppm (combustible gas)

Standard Circuit Conditions

loop voltage


≤24V  DC

heating voltage


5.0V±0.1V ACorDC

Load Resistance



Gas sensor characteristics under standard test conditions

heating resistance


29Ω±3Ω(room temperature)

Heating power consumption



The output voltage


2.5V~-4.0V(in 2000ppm C3H8 )



Rs(in air)/Rs(2000ppm C3H8 )≥5

Concentration slope


≤0.6(R3000ppm/R1000ppm C3H8)

 Standard Test Conditions

temperature humidity


Standard Test Circuit

Vc:5.0V±0.1V;  VH: 5.0V±0.1V

Preheat time

Not less than 48 hours

oxygen content

21% (not less than 18%, the oxygen concentration will affect the initial value, sensitivity and repeatability of the sensor, please consult when using it under low oxygen concentration)


10 years

Note: The output voltage (Vs) refers to the VRL in the test atmosphere

production workshop


patent certificate

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