15 Essential MQ Gas Sensors

Here's a not entirely comprehensive list of the MQ gas sensors often seen being used in Arduino smoke alarm or breathalyser projects. Like mine for example. I also have 2 of these set up as analog sensors on my Enviro pHat connected PiZero. One being an MQ135 and the other MQ-2. Not sure why I need to keep an eye on gas leaks in the living room but you never know! MQ-135 may make a bit more sense though to be honest it keeps a pretty still 0.41 value for the past several days. I may replace it with the optical Sharp GP2Y1010AU0F dust sensor as a general air quality indicator.

  • MQ-2 - Methane, Butane, LPG, smoke
  • MQ-3 - Alcohol, Ethanol, smoke
  • MQ-4 - Methane, CNG Gas
  • MQ-5 - Natural gas, LPG
  • MQ-6 - LPG, butane gas
  • MQ-7 - Carbon Monoxide
  • MQ-8 - Hydrogen Gas
  • MQ-9 - Carbon Monoxide, flammable gasses
  • MQ131 - Ozone
  • MQ135 - Air Quality (CO, Ammonia, Benzene, Alcohol, smoke)
  • MQ136 - Hydrogen Sulfide gas
  • MQ137 - Ammonia
  • MQ138 - Benzene, Toluene, Alcohol, Acetone, Propane, Formaldehyde gas, Hydrogen
  • MQ214 - Methane, Natural gas
  • MQ216 - Natural gas, Coal gas

While you're here you may find the following tutorial on how to read MQ sensor values using a Raspberry Pi and how to convert its analog data output to a digital output for the Pi.