This Liquefied Petroleum Gas (LPG) sensor is suitable for sensing LPG (composed of mostly propane and butane) concentrations in the air. It can detect 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.