Natural Gas Sensor

This is an Arduino CH4 gas sensor.  It uses an MQ4 probe which is able to detect natural gas, CH4. It is less sensitive in detecting alcohol, cooking fumes, and cigarette smoke.

The sensitivity can be adjusted by the potentiometer. The output is proportional to the density of the gas. You can use analog reading to read the data from this sensor. 

To ease the difficulty of using this sensor,  a Gravity Interface is adapted to allow plug&play.  The Arduino IO expansion shield is the best match for this sensor connecting to your Arduino microcontroller.  

Improvement List

• Standard assembling structure (Times-of-5mm Center distance between two 3mm(0.12") mounting holes)
• Easily recognitive interfaces of sensors ("A" for analog and "D" for digital)
• Icons to simply illustrate sensor function 
• High-quality connector
• Immersion gold surface

• Power supply: 5V
• Interface type: Analog
• Pin Definition:  1-Output  2-GND  3-VCC
• High sensitivity to CH4, Natural gas
• Small sensitivity to alcohol, smoke
• Fast response
• Stable and long life
• Simple drive circuit
• Size: 40x20mm(1.57"x0.79") 

1 x Arduino CH4 Gas sensor (MQ4)

• Arduino Playground: MQ Gas Sensors Tutorial
• Datasheet 
• Schematic