The UV spectrum lies between 200 nm and 400 nm and is commonly divided into three regions:UV-A: 320-400 nm; UV-B: 280-320 nm ; UV-C: 200-280 nm .The highest energy region, UV-C is absorbed completely by ozone in the stratosphere. Of the solar UV radiation reaching the earth’s surface, 6% is in the UV-B region and 94% in the UV-A.The potential of UV radiation to cause skin damage rises exponentially with decreasing wavelength. UV light at 280 nm is 1000 times more damaging than light at 340 nm so a fabric’s ability to block UV-B is the most important factor in preventing the negative side affects of sun exposure. UV Transmittance / Sunscreen Protection Factor Analyzer is an integrated UV spectrophotometer, designed and optimized for the determination of SPF values on a variety of sunscreen and cosmetic products, as well as materials testing. This self-contained, attractive desktop unit reduces the need and ass...