Visible light wavelength range: 400-760nm.
Ultraviolet light wavelength range: below 400nm.
Visible light is the part of the electromagnetic spectrum that can be perceived by the human eye, and there is no precise range of the visible spectrum; the wavelengths of electromagnetic waves that can be perceived by the average human eye range from 400 to 760nm, but there are others who can perceive electromagnetic waves with wavelengths of about 380 to 780nm.
Ultraviolet light is a general term for radiation in the electromagnetic spectrum with wavelengths from 0.01 to 0.40 micrometers, which can't cause people's vision. Electromagnetic spectrum in the wavelength from 0.01 ~ 0.4 micron radiation, both visible light violet end to the radiation between X-rays. Has the function of sterilization.
Extended information:
Visible light is the part of the electromagnetic spectrum that can be perceived by the human eye, and there is no precise range of the visible spectrum; the general human eye can perceive the electromagnetic waves of wavelengths between 400 and 760 nm, but there are others who can perceive electromagnetic waves with wavelengths between about 380 and 780 nm.
The human eye with normal vision is most sensitive to electromagnetic waves with a wavelength of about 555nm, which is in the green light region of the optical spectrum. The range of light visible to the human eye is influenced by the atmosphere. The atmosphere is opaque to most electromagnetic radiation, with the exception of the visible light band and a few others such as the radio communication band.
Many other organisms can see light in a different range than humans, for example, some insects, including bees, can see in the ultraviolet range, which is useful for finding nectar. A recent study has found that visible light may also be able to "see through" the physical body.
Visible radiation generally refers to radiation in the 0.38 to 0.76 micron band of the solar radiation spectrum, which consists of seven colors of light: violet, blue, blue, green, green, yellow, orange and red. It is the necessary and effective solar radiation energy for photosynthesis in green plants. Visible radiation reaching the earth's surface varies with atmospheric turbidity, solar altitude, cloud cover and weather conditions. Visible radiation accounts for about 45 to 50% of the total radiation.
Ultraviolet light is electromagnetic radiation with a shorter wavelength than visible light, but longer than X-rays. Ultraviolet light in the electromagnetic spectrum in the range of wavelengths of 10-400 nm. This range begins in the short-wave limit of visible light, and overlap with the long-wave wavelengths of X-rays. Ultraviolet light is divided into A-rays, B-rays and C-rays (referred to as UVA, UVB and UVC), with wavelength ranges of 400-315 nm, 315-280 nm, and 280-190 nm, respectively.
Function 1 Germicidal
This is the most common function of ultraviolet rays, and since ultraviolet rays have a powerful killing power for living things, humans use it to deal with These difficult bacteria, viruses, we also often use sunlight to help us sterilize. It is important to note that these germicidal devices can harm the human body, so be careful when using them.
Function 2: Identification and Visualization
Because ultraviolet light is more penetrating than normal visible light, scientists often use ultraviolet light for visualization or identification work (like using X-rays for health checks). For example, ultraviolet light can be used to examine minute cracks in metals, the authenticity of drawings, food safety, and even in space exploration.
Function 3: Health and medicine
Excessive UV exposure can cause damage to the human body, but proper sunlight can help the body synthesize vitamin D.
Recently, medical science has found that exposure to the right amount of A or B light can also treat skin lesions such as tinea cruris, white spots, and other skin conditions, so that patients are no longer "itchy". "
Function 4: Showing the way for insects
Because every living thing receives a different range of light frequencies, some animals rely on ultraviolet light in order to find their way around or see things clearly. For example, bees need UV light to find nectar and pollinate flowers. In addition, ultraviolet light helps plants to photosynthesize.
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