Description

MQ-2 is a  Semiconductor Sensor for Combustible Gas and Smoke

This  sensor detects the concentrations of combustible gas in the air and output its reading as an analog voltage.

MQ-2 gas sensor has high sensitivity to LPG, Propane and Hydrogen, also could be used to Methane and other combustible gas.

Sensitive material of MQ-2 gas sensor is Tin Di-Oxide SnO2, which has lower conductivity in clean air. When the target combustible gas exist, MQ 2 senses and its  conductivity is more higher along with the gas concentration rising.

A simple electronic circuit is used to convert change of conductivity to corresponding  output signal of gas concentration.

MQ-2 has 6 pins, 4 of them are used to fetch signals, and other 2 are Heater coil used for providing heating current.