eli5: How does my UV flashlight have a higher uv index rating than the Sun

Question

When I measured the sun, it gave a UV index of 6. When I measured the uv flashlight, it gave a uv index of 196. Is the sun not more powerful in UV than the flashlight?

In: Physics

Answer 1

While the sun is immensely bright, it’s also far away. We can make artificial lights that, relative to the distance from the source to you, are brighter than the sun. Same concept with UV. Your UV flashlight may not be on the same order of magnitude of intensity as the sun, but it’s magnitudes closer, so more of the photons hit you and/or your sensor.