MQ-2 gas sensor high on gas, propane, hydrogen sensitivity of detection of natural gas and other flammable vapors are also very good. This sensor can detect a variety of flammable gas, is a low-cost sensors for a variety of applications.
in addition the Gas may be used in homes and factories leakage monitoring device suitable for the detection of gas, butane , propane , methane , smoke , etc.
VCC: positive power supply (5V)
GND: power supply is negative
DO: TTL switching signal output
AO: analog signal output