Ultraviolet flame detector and infrared, visible flame detector
1, ultraviolet flame detector USES flame itself if there are special ultraviolet intensity to discriminate flame, the photoelectric device for ultraviolet light tube.
Adjacent to the burner flame have higher resolution, usually used as a single burner flame detector.
Ultraviolet flame detector is commonly used in fuel and gas boiler, but is not suitable for inert gas content larger fuel combustion conditions.
This kind of flame detector using the flame itself unique ultraviolet intensity to determine the presence of.
Ultraviolet wavelength range is relatively narrow, between 10 ~ 400 nm, probe using of visible light and infrared is not sensitive to uv photocell.
2, infrared flame detector.
There are a lot of visible light in a flame of fire, and 0.
More than 9 nm infrared, the wavelength of the light not easily absorbed by dust and water vapor and other products of combustion, thus suitable for detecting pulverized coal flame, heavy oil and larger fuel combustion conditions suitable for inert gas content.
Infrared flame detector through infrared detection of combustion flame radiation intensity and frequency of flame in flame exists, probe the lead sulfide photocell or silicon photodiode.
Due to the combustion chamber of a stove or furnace with fire flames flicker frequency is usually not more than 2 hz, so through the filter circuit, infrared flame detector can distinguish between flame burner flame and background.
3, visible flame detector detect flame flicker frequency and visible brightness at the same time, and by using the Boolean operations to detect the existence of the burning flame.
At the same time by flame average light intensity and pulse flicker frequency signal, can improve the reliability of detection.
However, visible light are easy to be oil mist, smoke and unburned pulverized coal block and absorption, and the infrared have certain ability to penetrate, so infrared detection is more ideal than visible light detection.