Combustible gas detector is a detector that responds to the concentration of single or multiple combustible gases. There are two types of combustible gas detector: catalytic type and infrared optical type. Catalytic combustible gas detector uses the resistance change of platinum wire after heating to measure the concentration of combustible gas. When combustible gas enters the detector, it causes oxidation reaction (flameless combustion) on the surface of platinum wire. The heat generated by it makes the temperature of platinum wire rise, and the resistivity of platinum wire changes. Infrared optical type uses infrared sensor to detect the hydrocarbon combustible gas in the field environment through the absorption principle of infrared light source.