DFI-150-0003 ALSTOM Flame indicator

According to the light characteristics of the flame, there are three kinds of flame detectors used: one is the ultraviolet detector sensitive to the short wavelength ultraviolet radiation in the flame; The other is the infrared detector sensitive to the longer wavelength infrared radiation in the flame; The third is a hybrid UV/IR detector that detects both the shorter wavelength UV and the longer wavelength infrared in the flame.
Specific according to the detection band can be divided into: single ultraviolet, single infrared, double infrared, triple infrared, infrared/ultraviolet, additional video and other flame detectors.
According to the explosion-proof type can be divided into: flameproof type, intrinsic safety type.

For 0.185~0.260 micron wavelength UV produced in flame combustion, a solid substance can be used as a sensor, such as silicon carbide or aluminum nitrate, or an inflatable tube can be used as a sensor, such as a Geiger – maitreer tube.
For infrared ray with wavelength of 2.5~3 microns generated in flame, sensor made of aluminum sulfide material can be used, and for infrared ray with wavelength of 4.4~4.6 microns generated by flame, sensor made of lead selenide material or aluminum tantalate material can be used. Different sensors can be selected according to different fuel emission spectra. Triple infrared (IR3) is widely used.