Methane CNG Gas Sensor - MQ-4

This is a simple-to-use compressed natural gas (CNG) sensor, suitable for measuring natural gas (mostly methane [CH4]) concentrations in the air. The MQ-4 can detect natural gas concentrations ranging from 200 to 10000 ppm. This sensor has a high sensitivity and fast response time. The sensor's output is an analog resistance. The drive circuit is very simple: power the heater coil with 5V, add a load resistor, and connect the output to an ADC. This sensor comes in a package similar to our MQ-3 alcohol sensor, and can be used with the breakout board below.