This is a very easy to use and very handy gas sensor ,suitable for sensing Alcohol gas cocentration. This sensor MQ-3 can detect Alcohol gas concentrations anywhere from 200 to 10000ppm. The MQ-3 sensor has a very sensitivity to Alcohol gas.
The sensitive material of MQ-3 is SnO2, which has lower conductivity in clean air. When the target alcohol gas exist, the sensor’s conductivity is higher along with the gas concentration rising. MQ-3 sensor has high sensitivity to Alcohol, and good resistance to disturb of gasoline, smoke and vapour. The sensor could be used to detect alcohol with different concentration, it is with low cost and suitable for different application.
This sensor has a very simple; all you need to do is power the heater coil with 5V, add a load resistance, and connect the output to an ADC. This is a very simple easy to use LPG gas sensor, suitable for sensing Propane, Hydrogen, methane and LPG concentrations in the air. This sensor has a very fast response time and high sensitivity. The connections are as follow: First connect the Vcc pin to 5V with the microcontroller, and connect your GND to GND pin of arduino. Connect the AO pin to AO pin of arduino.
High sensitivity to Alcohol Rs (in air) Rs (0.4mg/l alcohol).