How can the layperson test whether a UVC light sold as “germicidal” is a fake or probably the correct wavelength?

Are there simple ways to test whether a light is likely short wave / UV-C, or at least whether it is probably a fake?

Real Example: 2 lights are allegedly germicidal and supposedly emit germicidal 254nm radiation.

  • Light 1 darkens transition glasses and emits the smell of chlorine / ozone.
  • Light 2 does neither but appears much brighter than Light 1.

Does the ozone smell of Light 1 entail that it at least emits radiation within the UVC band?

Assuming the glasses do darken outdoors and do darken in response to Light 1, given that they do not darken with Light 2, is it safe to conclude Light 2 emits no UV at all?

You can do the banana test to identify if it is real or fake.

Get a green banana and cover parts of it with a sticker you now need to expose the banana with the uv light for about one hour,the green banana will get brown/yellow at the exposed part and stay green under the sticker if the uv-c light is genuine…

It is best to do this in a dark room and the banana can not be in a plastic bag or any covering as this might stop the uv-c light.

The uv source needs to be close to the banana for this to work.

If the color of the green banana stay the same after the test your uv-c light is fake.

Never look directly at the uv-c light and do not shine the light on your bare skin.