How Is UV Wavelength Determined?

Ultraviolet is a general term for radiation with a wavelength of 10 to 400 nanometers in the electromagnetic spectrum, which cannot cause people's vision. In 1801, German physicists discovered that the outer part of the purple end of the sunlight spectrum can sensitize the photographic film containing silver bromide, and found the existence of ultraviolet rays. Ultraviolet rays can be used for sterilization, but too much UV rays can cause skin cancer in the body.

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Ultraviolet rays can be divided into near-ultraviolet UVA, far-ultraviolet UVB and ultra-short ultraviolet UVC according to the wave.

UV curing technology uses UV light (main wavelength: 365nm, special occasions: 254nm) to irradiate UV-curing resins containing coatings, adhesives, or inks that contain photorecombinable prepolymers, photorecombinable monomers, and photoinitiators. The unit's rapid hardening and drying technology. However, the drying of the resin usually requires several minutes to several hours by the common thermal drying method and the superposition reaction method in the two-liquid mixing method.

UV surface sterilization devices are widely used in food, electronics, semiconductors,

Another application of UV biological effects is biomutation breeding. The substance that determines the biological lineage is DNA. The DNA absorption spectrum of microorganisms is between 200 and 300 nm. When the DNA of microorganisms absorbs ultraviolet rays, the structure will change greatly, which will cause hereditary changes in microorganisms. In this way, the characteristics of microorganisms can be greatly changed in a short period of time.

When ultraviolet rays are irradiated, the degree of eye injury is proportional to the time, inversely proportional to the square of the distance of the irradiation source, and related to the angle of light projection.

When the ultraviolet rays strongly affect the skin, photodermatitis can occur, and erythema, itching, blistering, edema, eye pain, tearing, etc. appear on the skin; serious can also cause skin cancer.

Ultraviolet rays act on the central nervous system and can cause headaches, dizziness, and elevated body temperature. Acts on the eyes and can cause

UV instrument testing

When ultraviolet rays of a certain intensity and wavelength are irradiated to the substance (some substances need to be added with fluorescent dyes), the substance elements will emit fluorescence (photoluminescence). The content of the element can be determined based on the color of the fluorescence. Such as lead, mercury and other heavy metals, pesticide residues can be detected by this method. Fluorescent lamps use this principle.

UV black light

The compound eyes of most insects are particularly sensitive to 365nm ultraviolet light. At night, turning on a UV lamp is like a bright world for insects.

UV human health exposure

Ultraviolet rays of 280 to 320 nm are called health ultraviolet rays. After the skin is irradiated, the 7-dehydroergot cholesterol in the skin is converted into vitamin D ₃ and D ₂ to prevent rickets and occupational diseases (miners, etc.).

There are already health-care UV lamps on the market.