Description: This is a simple-to-use compressed natural gas (CNG) sensor, suitable for sensing natural gas (composed of mostly Methane [CH4]) concentrations in the air. The MQ-4 can detect natural gas concentrations anywhere from 200 to 10000ppm.
This sensor has a high sensitivity and fast response time. The sensor's output is an analog resistance. The drive circuit is very simple; all you need to do is power the heater coil with 5V, add a load resistance, and connect the output to an ADC.
This gas sensor can be used with the Gas Sensor Breakout, simplifying the interface from 6 to 3 pins-ground, power and analog voltage output-that are broken out with a 0.1" spacing. This board has two mounting holes and provides convenient pads for mounting the gas sensor's required sensitivity-setting resistor.