The MQ series of gas sensors use a small heater inside with an electro-chemical sensor. They are sensitive for a range of gasses and are used indoors at room temperature. The output is an analog signal and can be read with an analog input of the Arduino.
The MQ-2 Gas Sensor module is useful for gas leakage detecting in home and industry. It can detect LPG, i-butane, propane, methane ,alcohol, hydrogen and smoke.
Some modules have a built-in variable resistor to adjust the sensitivity of the sensor.
Note: The sensor becomes very hot after a while, don't touch it!
In this tutorial we will use the serial monitor of Codebender (or Arduino IDE) to see how the sensor acts in variable gasses.
So, let's get started!
For this tutorial you will need: