This module is made using Alcohol Gas Sensor MQ3. It is a low cost semiconductor sensor which can detect the presence of alcohol gases at concentrations from 0.05 mg/L to 10 mg/L. The sensitive material used for this sensor is SnO2, whose conductivity is lower in clean air. It?s conductivity increases as the concentration of alcohol gases increases. It has high sensitivity to alcohol and has a good resistance to disturbances due to smoke, vapour?and gasoline. This module provides both digital and analogue outputs. MQ3 alcohol sensor module can be easily interfaced with Micro controllers, Arduino Boards, Raspberry Pi etc.