What is the Ultraviolet index?
The [ultraviolet (UV) index] is an international standard measurement of the strength of sunburn-causing ultraviolet radiation at a particular place and time. The UV index is designed as an open-ended linear scale that is directly proportional to the intensity of ultraviolet radiation. This means that the UV index proportionately reflects the intensity of ultraviolet radiation and how quickly rapidly an exposed individual may expect to sunburn.
Why is the Ultraviolet index important?
The purpose of the UV index is chiefly for notifying the general public in weather reports to help them protect themselves. While UV radiation is beneficial in moderation, over-exposure has numerous detrimental effects such as sunburn, skin aging, DNA damage, skin cancer, immunosuppression and eye damage.
Using the UV index, one can understand the degree of when spending an extended amount of time outdoors, in direct sunlight. There are many ways to protect oneself from UV radiation, such as the regular application of sunscreen, wearing a wide-brimmed hat and sunglasses and staying in the shade when the UV index is highest (midday).
How is the Ultraviolet index calculated?
Calculating the ultraviolet index is quite complicated . Meteorological surveys and weather services use detailed computer models that take many different factors into account including, the thickness of the Ozone Layer, cloud cover, elevation etc.
As best described by the United States Environmental Protection Agency through this link, a series of weights is applied to the measured (or predicted) intensity of each wavelength of UV radiation across the ultraviolet spectrum, excluding the UVC ranges. These weightings account for the greater degree of damage done by the shorter wavelengths to the skin and for the absorption of these shorter wavelengths by stratospheric ozone.
In the case of ☒CHIPS the UV index displayed is calculated from the measurements made by the SL01 ☒CHIP with several additional calculations and correction and compensation factors included to account for the sensor being a broadband radiometer.