The gas sensitive material used in MQ-6 gas sensor is SnO2, which is of lower electrical conductivity in clean air.
When there is combustible gas in the environment where sensor resides, the electrical conductivity of the sensor increases with the increase of the combustible gas concentration in the air.
The change of electrical conductivity can be converted to the output signal corresponding to that of the gas concentration by using a simple circuit.
The sensitivity of MQ-6 gas sensor to propane, butane and liquefied petroleum gas is quite high, and the natural gas can also be well detected.
This sensor can detect a variety of combustible gases, making it a low-cost sensor for a variety of applications.