Beauty Tips For Body Care
I've got some interesting results for those wondering how much UV exposure they're getting inside. I measured diffuse UV levels from my window using a UV meter. The window is north facing with about 20% of the light being blocked by a tree. There is no direct sunlight, only diffuse light that passes through the window. The device is a NIST-traceable calibrated meter, measuring total UV in units µW/cm2. Solar irradiance at Earth’s surfaceOn a clear day at noon, The total amount of solar radiation that hits the earths surface is about 100,000 µW/cm2 . The UV portion of the total is 8%. So 8,000 µW/cm2 of total UV hits the earth. 95% of this total is UVA, 7600 µW/cm2. The remaining 5% being UVB, 400 µW/cm2.The UV results were measured at 12:30pm on a clear day today, in units µW/cm2 :At window: 2505 ft away: 10810ft: 2515ft: 12UV intensity decreased significantly the further away from the light source. This is due to the inverse square law.Here are the results as a percentage of total UV:At window: 250/8000, 3.125%5 ft: 108/8000, 1.35%10ft: 25/8000, 0.31%15ft: 12/8000, 0.15%Conclusion:These results are not universal and may change depending on location, time of year and time of day. However I think its safe to say that exposure from diffuse UV is minimal inside. If you want to be extra cautious, stand 5+ feet away from the window to bring your UV exposure near 0. Having obstructions like trees in your field of view help as well.
Girls Blog 2015
Submitted by messenger4u
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