J.R. S. answered • 07/08/19
Ph.D. University Professor with 10+ years Tutoring Experience
Here is one possible way to test your if your film is blocking uv light.
Get a piece of black cardboard, a yellow magic marker/yellow highlighter and a uv flashlight. You can buy a uv flashlight for less than $10(US).
Write on the black cardboard with the yellow marker and then shine the uv light on it and you will see it "phosphoresce" or "light up". Then pass your film between the uv light and the cardboard, and if your film is blocking the uv light, you will not be able to read what you wrote. This entire experiment should cost less than $15 US.
Aditya Shankar M.
Also uvb light07/08/19
Aditya Shankar M.
But is that uv torch emitting light from wavelength 290 nm to 390 nm the entire range of uva light and can the ink light up to the whole spectrum of uva light. Otherwise there is no way to know if the film is actually impermissible to uva light's complete spectrum and not just partially.07/08/19