The S600-ExIR1 point type infrared flame detector contains an infrared sensor and an optical filter. The detector has the highest sensitivity to the CO2 emission spectrum (4.4 μ m) produced by the combustion of hydrocarbons. Combined with the logical comprehensive judgment of the flame flicker frequency during a fire, it has a high immunity to false alarms caused by environmental infrared light sources. Due to the complexity of the daylight source and the fact that the detector only uses a single wavelength infrared sensor for flame detection, the product is suitable for indoor working environments. The detector is suitable for liquid and gas fires, open flames that produce smoke, and places where explosions occur.