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UV classifications include UVA (320-400 nm), UVB (290-320 nm) and UVC (200-280 nm). UV-absorbing compounds are used not only in sunscreen, but also in other personal care products, such as lipstick, shampoo, hair spray, body wash, toilet soap, and insect repellent. [ 2 ]
UVA 315–400 Ultraviolet B 3.94–4.43 0.631–0.710 Medium-wave UV, mostly absorbed by the ozone layer: intermediate UV; Dorno radiation. UVB 280–315 Ultraviolet C 4.43–12.4 0.710–1.987 Short-wave UV, germicidal UV, ionizing radiation at shorter wavelengths, completely absorbed by the ozone layer and atmosphere: hard UV. UVC 100–280
Next in frequency comes ultraviolet (UV). In frequency (and thus energy), UV rays sit between the violet end of the visible spectrum and the X-ray range. The UV wavelength spectrum ranges from 399 nm to 10 nm and is divided into 3 sections: UVA, UVB, and UVC.
There are four UVB types of lamps: Fluorescnt Broad-Band UVB that emit 280-330 nanometer, Fluorescent Narrow-Band that emit 312 nanometer, Excimer that emit 308 nanometer and LED that emit 290-300 nanometer. PUVA means UVA + psoralen. It consists of irradiation of the skin with the UVA ultraviolet light, from a fluorescent bulb or LED lamps.
As ozone does exist in the atmosphere, the Dobson Spectrometer can use the ratio between UVA and UVB radiation on the ground to determine how much ozone is present in the upper atmosphere to absorb the UVC radiation. The ratio is determined by turning the R-dial, which can be rotated a full 300°, on the instrument.
Because UVC can be deadly, a special dichroic filter glass (usually purple) is required that will filter out the UVC and UVB. The goal with high-pressure tanning bulbs is to produce a high amount of UVA only. Unfiltered light from a high-pressure lamp is rich in UVC used in germicidal lamps, for water purification, but it damages human skin.
An ultraviolet detector (also known as UV detector or UV-Vis detector) [1] [2] is a type of non-destructive chromatography detector which measures the amount of ultraviolet or visible light absorbed by components of the mixture being eluted off the chromatography column.
In contrast, fluorescent UVB lamps come in two types: broadband (or wideband) and narrowband. Broadband UVB lamps have a peak wavelength of 306 nanometers. Since only a small portion of their spectrum falls near the optimal 297 nanometers, these lamps require a higher dose of 0.5 joules per square centimeter.