The concepts of violet light, ultraviolet light, and ultraviolet light are often confused. Violet light refers to electromagnetic waves with wavelengths between 400-450 nm and is the shortest wavelength in visible light. Ultraviolet light and ultraviolet light are different versions of the same electromagnetic wave, which are lightly invisible to human eyes. Ultraviolet and ultraviolet lights refer to electromagnetic waves between the violet light of visible light and X-rays, and the wavelength range of electromagnetic waves is between 200-400 nm.
UV LED Application
UV LED (ultraviolet LED)
(1) Low UV: 250nm-265nm-285nm-365nm, now 250nm-410nm can be achieved. These are all InGaN/GaN material carbides. These UVs kill all bacteria in water up to 98%, especially at 285 nm.
(2) Medium-ultraviolet light: 365 nm -370 nm lights is used internationally. Ultraviolet light has deadly power. Generally, doctors are required to ensure that there are no bacteria during surgery. 365nm-390nm generally use this ultraviolet to fill dentists. They are characterized by: strong function and short time. At the same time, we use the wavelength of 365nm-370nm internationally to identify the authenticity of banknotes.
(3) High UV light: 405 nm -410 nm, the maximum chip size is no more than 2 inches (also called UV chip). From 345-410nm can be used to cultivate plant seeds.405nm-410nm can distinguish the authenticity of RMB banknotes.
Use of special bands
(1) 250 nm-300 nm (0.1MW), 350 nm-360 nm (1MW), 380 nm-400 nm (5MW, 20MA). The product is excited by light in the 320nm~400nm band, which can effectively remove formaldehyde, benzene, and xylene in the air in the office and viruses, bacteria, and odours in the daily office air, prevent virus infection and reduce the spread of diseases. At the same time, it can promote metabolism in the body, enhance immunity, make us energetic, and keep our family healthy.
(2) The wavelength of 570-580 nanometers causes the mosquito retina to blur and let it escape automatically.
(3) 320 nm~380 nm UV can promote skin metabolism, promote strong skin growth, thicken skin, and treat psoriasis and vitiligo.
When used for lighting, the fluorescence effect of the illuminated object can be strong, and we can use it for industrial radiation detection, chemical phase formation, banknote detection, and so on.
(4) 275nm~320 nm ultraviolet rays; sunbathing has a powerful physiological effect on the human body.
It can cause photochemical and spot processes in the skin, making the skin produce many active substances. These substances can act on the viscera, mental and endocrine systems, and circulatory systems of the human body.
Good effect; when people expose to sunbathing, it causes skin redness and produces an erythema effect. On the other hand, it converts 7-dehydroergot cholesterol in the skin into vitamin D3 or D2 and promotes the normal calcium and phosphorus circulation of humans. It is very important for pregnant women and young children.
(5) The use of insects’ vision has the characteristics of maximum sensitivity in the ultraviolet region near 360nm; it can lure insects together and kill them.
(6) The particular wavelength of 315nm, the ultraviolet B bands have a strong physiological effect on animals. And they can play a positive role in the general work of the internal organs, nervous system, endocrine system, and circulatory system of animals and promote the synthesis of protein and vitamin D3.
LED ultraviolet sterilization as a disinfection method is not a recent new technology. Because ultraviolet disinfection cannot be seen or touched, it is understandable for consumers to feel that there is no effect psychologically. But after understanding the principle of LED UV disinfection, there will be no such worries.
Let us start with a simple science: we divided ultraviolet rays into UVA (320-400nm), UVB (280-320nm), and UVC (100-280nm) according to different wavelengths. Among them, UVC LEDs outside the wavelength can destroy the DNA or RNA molecular structure of microbial cells by emitting ultraviolet lights so that bacteria or viruses can die and achieve the effect of sterilization and disinfection.
According to research, UVC ultraviolet light with a wavelength of about 250-260nm has the most potent bactericidal effect. Therefore, the ultraviolet sterilization we are talking about is mainly UVC deep ultraviolet sterilization.
However, due to the relationship between wavelength and energy efficiency, the UV light source currently used for medical sterilization mainly comes from UV mercury LEDs. The mercury LED adds mercury (mercury) into the vacuum quartz LED tube, discharges through the voltage difference between the two ends of the electric shock, excites the ultraviolet radiation wave, and then changes the wavelength through the fluorescent paint inside the LED tube.
However, the ultraviolet mercury LED is seriously polluting the environment because it contains mercury.
Therefore, LED ultraviolet disinfection products must be mainstream in the future.
What is the principle of UV sterilization?
Ultraviolet rays act on the genetic material of biological cells, namely DNA, and destroy DNA, resulting in the death of bacteria.
In addition, ultraviolet rays at specific bands can interact with foreign air in the air to produce the ozone layer， which has a strong oxidizing effect, thus killing bacteria.
What kind of UV light can we use for sterilization?
Studies have shown that the UVC band (200-280nm) is the most germicidal part of ultraviolet light.
For different microorganisms, the sterilization effects of different wavelengths are different. Ultraviolet rays have a better bactericidal effect on major infectious diseases. Such as dysentery, cholera, and enteritis.
According to the technical standards of disinfection and sterilization, each microorganism has its specific UVC sterilization dose (irradiation intensity • time)criterion.
How long does it take to disinfect with a UV LED?
When using ultraviolet LEDs for disinfection, we need to determine the length of disinfection time according to the temperatures and humidity of the room.
Generally speaking, the disinfection time is generally not less than 30 minutes, especially when the temperatures are lower than 20 ℃ or higher than 40 ℃, and the relative humidity is greater than 60%. We should extend the disinfection times.
What are the reasons that affect the disinfection effect of UV LEDs?
① Ultraviolet wave band;
② The type of UV LED and the presence or absence of a reflector;
③ The cleanliness of the UV LED;
④ Irradiation intensity, irradiation distance, and irradiation time;
⑤ Temperatures and humidity;
Can UV light kill the coronavirus?
Coronaviruses are protein-wrapped single-stranded positive-stranded RNA viruses. In addition to the new coronavirus (2019-Nov) discovered this time, the most well-known ones are SARS and MERS coronaviruses.
During the SARS period, Scientists found that the SARS virus was sensitive to thermal radiation and UVC, with an intensity greater than 90 MW/cm2
half an hour of UVC irradiation can kill the SARS virus.
The researchers also simulated sunlight under natural conditions in the laboratory. And found that under the clear weather in the background area at 10 am in May， with an ultraviolet intensity of 4μW-5μW/cm2, 3 hours can kill the coronavirus in vitro. Virus.
How to deal with accidental UV damage?
① The skin is burned
Symptoms: skin redness, pain, obviously tenderness, oozing, oedema, etc.
Treatment: Mild burns require an immediate cold compress, which can usually be relieved within 24 hours. Severe burns should rush to the hospital for anti-inflammatory and anti-allergic treatment.
② Electro-optic ophthalmia
Symptoms: foreign body sensation in the eyes aggravated burning sensation, severe pain, photophobia, lacrimation, blepharospasm, conjunctival hyperemia, and conjunctival oedema.
Treatment: Go to the hospital for treatment.
What are the precautions for UV LED disinfection?
① The ultraviolet light source cannot irradiate people
② Be sure to standardize the installation
③ Keep the surface of the UV LED clean. If you find dust and grease on the surface of the LED tube, wipe it at any time.
④ When disinfecting indoor air with ultraviolet LEDs, we should keep the room clean and dry to reduce dust and water mist, the temperature should be lower than 20 ℃ or higher than 40 ℃, and we should extend the irradiation time appropriately when the relative humidity is greater than 60%.
⑤ The UV intensity meter should be calibrated at least once a year
⑥ Zone will be generated during the UV disinfection process. Open the windows for ventilation immediately after disinfection.
Everyone knows that everything has two sides. Ultraviolet rays play an important role in sterilization and disinfection. At the same time, it does not hurt human skin. The following is about the damage of ultraviolet rays to human skin.
1 Under UVA ultraviolet rays, with a wavelength of 320-400nm, it has strong penetrating power on the skin. And can reach the dermis layer of the skin, destroying elastic fibres and collagen fibres and tanning the skin.
UVC is very harmful to the human body. Short-term exposure can burn the skin. Long-term or high-intensity exposure can also cause skin cancer.
2 Under UVB ultraviolet rays, that is, with a wavelength of 290-320nm, it has moderate penetration and can penetrate the epidermis to the dermis surface, which can cause erythema, inflammation, and other light damage to the skin, which is the root cause of skin sunburn.
UVB has a rapid effect on the skin and can cause a photosensitivity reaction in the skin. It is the main band to prevent UV sunburn.
3 Under UVC ultraviolet rays, that is, when the wavelength is 200-290nm, the penetrating ability is the weakest, only reaching the stratum corneum of the skin, and most of it is blocked by the atmosphere, so it will not cause harm to human skin.
UVA has a slow and long-lasting effect and generally does not cause acute inflammation of the skin, but its effect on the skin is an irreversible accumulation effect.
So how much do you know about LED UV light? Feel free to leave us a message in the comment area at any time, or you can learn more about LED UV light in the following ways.
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