They are used in gas leakage detecting equipment in family and industry, are suitable for detecting of LPG, natural gas, town gas, avoid the noise of alcohol and cooking fumes and cigarette smoke.
https://www.mysensors.org/dl/57c3ebeb071cb0e34c90057a/design/MQ5.pdf
https://www.mysensors.org/dl/57c3ebeb071cb0e34c90057a/design/MQ5.pdf
