The Grove sensor series features a set of inexpensive, interesting gas sensor modules. Here, the MQ9 sensor specializes detecting Carbon Monoxide, Coal gas (CH4), and Liquified Natural Gas vapour.

Specifications:

• Grove interface compatible
• Hanwei Electronics MQ9 sensor
• Sensitive to
  • Carbon Monoxide CO (10-1000 parts per million)
  • Methane CH4 (100-10,000 parts per million)
  • Liquified Petroleum Gas LPG (100-10,000 parts per million)
• 4.9-5.1VDC
• 0.5-800mW power consumption
• Adjustable load resistance
• 33ohm heater resistance
• 3-30k sensor resistance
• -25 to +70 degrees C (-13 ~ 158 deg F) operational temperature
• Stable performance, long life, low cost

Links:

• Gas Sensor (MQ9) Wiki
• Seeed Wiki How to choose a Gas Sensor