MQ-3 module is has a high sensitivity for detecting Alcohol and low sensitivity for Benzine, CH4, Hexane, LPG, CO. The module gives out the concentration of the gases as an analog voltage equivalent to the concentration of the gases. The module also has an onboard comparator for comparing against an adjustable preset value and giving out a digital high or low.
Copy the following code to your Arduino IDE to test the MQ 5 Module
Testing MQ 3 GAS Sensor with serial monitor
Suitable for detecting of Alcohol, Benzine, CH4, Hexane, LPG, CO.
Dev: Tom Joseph, www.tomsonelectronics.com
const int gasPin = A0; //GAS sensor output pin to Arduino analog A0 pin
Serial.begin(9600); //Initialize serial port - 9600 bps
delay(1000); // Print value every 1 sec.
Detecting Concentration:0.05-10mg/L Alcohol
Analog and Digital Output
Digital Out is High or Low based on an adjustable preset threshold.