The MQ-2 is a smoke and combustible gas sensor from Winsen. It can detect flammable gas in a range of 300 - 10000ppm. It's most common use is 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 straight-forward, but does require some calibration.
For easy Solderability; use our Gas Sensor Breakout Board.