Deep ultraviolet sterilization small science
发布时间：2021-05-19 16:17
来源：萤光创新
With the development of the Novel coronavirus (COVID-19) outbreak, health risks lurk all over the world, from our families to society. And we have to respond in various ways to the sources of risk, the water, the objects, the air, everything that we come into contact with.
UVC is what?
Ultraviolet light is invisible light with a wavelength of 100 ~ 400nm.
Ultraviolet light in the wavelength range of 100 to 280nm is called uv-c (deep ultraviolet) and has functions such as sterilization, organic decomposition, photopolymerization and sensing.
Sunlight also contains UVC, but because of the ozone layer in the atmosphere, most of the ultraviolet rays from sunlight are absorbed by the ozone layer and do not reach the earth's surface before they reach the surface. Deep ULTRAVIOLET LED sterilization is the use of deep ultraviolet light-emitting diode, artificial deep ultraviolet and its application in the field of sterilization.
Ultraviolet sterilization characteristics
There are many ways to kill bacteria in the world, such as heat and chemicals, and ultraviolet sterilization is the use of ultraviolet light to kill bacteria. It has characteristics that no other bactericidal method has and is used for many different purposes.
| advantages | disadvantages |
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· Since no chemicals are used, there is no need to wipe or remove after use.
· Chlorine-resistant microorganisms that are ineffective for chlorine sterilization are also available
· No resistance to ultraviolet sterilization
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· Human and biological health hazards (acute/chronic UV damage)
· Damage to organic materials such as resins
· Do not sterilize where there is no light or shadow
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※That is to say, the so-called solar disinfection (sun exposure) does not contain the bactericidal effect of UVC.
The sterilization in this case is mostly due to drying and heat.
UVC is harmful to the human body. Do not look directly at or illuminate the skin.
In addition, when using, please pay attention to ultraviolet light leakage and reflected light.
The sterilization effect of external sterilization depends on
Intensity of light (illuminance) * the cumulative duration of light exposure.
The longer the exposure, the more light accumulated, the better the bactericidal effect.
On the other hand, the shorter the illumination time, the less the amount of accumulated light, sterilization effect is poor.
So, to kill bacteria in a short period of time, you need very strong ULTRAVIOLET light
The concept of luminous flux
Example: when A dose of 40mJ/cm2 is required for 99.99% sterilization of bacteria A
Since illumination * irradiation time = luminous flux, the illumination and time required are:
2mW/ square centimeter *20s=40MJ/ square centimeter
Or 1mW/ square centimeter *40s=40MJ/ square centimeter
