Department of Electrical, Electronics and Communication Engineering
Indian Institute of Technology Dharwad
MQ2 Gas Sensor
MQ series sensor uses a small heater inside with an electrochemical sensor in order to measure a different kind of gases combination. They can be calibrated, but, in order to do that, a known concentration of measured gas or gases is needed. In our case, we will test it, as it comes from the producer without any additional calibration. The MQ2 Gas sensor has a built-in variable resistor that changes its value according to the concentration of gas. If the concentration is High, the resistance decreases, if the concentration is low, the resistance increases. Besides the built-in resistor, it is necessary to include load resistor, Load resistor serve to adjust sensor sensitivity and accuracy, it’s value can range from 2k ohm to 47 k ohm higher the value, the more sensitive sensor becomes.
Pin description
MQ2 Gas sensor has 4 pins
VCC
GND
AOUTÂ (Analog Output pin)
DOUTÂ (Digital Output pin)
