Testing UV absorption eyewear and sunscreen with a deuterium light source

I use a deuterium light source to determine the absorption effectiveness of UV safety glasses and sunscreen, as well as common transparent materials.

Another interesting application of sunscreen, UV, and visual indicators:

References for CIE erythema action spectrum:

[AZREDFERN]

You should test a contact lens. A lot claim UV protection, especially the Acuvue Oasis’s I use.

[simonfitch]

You sure keep it interesting - I'm amazed how diverse your topics are, and every video is captivating. Thank you so much!

[Muonium]

One of the most fascinating realizations I've ever had in the lab was working with a deuterium lamp checking some antireflection coatings. I didn't understand why the output of such a lamp was continuous and wasn't just the Balmer or Lyman series of discrete lines. This was pre wiki days and the information wasn't readily available. Then using it one day suddenly I thought the light must not be coming from individual atoms, it must be coming from exited D2 MOLECULES! This led me to the whole new world of rovibrational excited state coupling, bremsstrahlung processes, etc. It still totally amazes me how such rich, tremendous complexity can arise from such an incredibly simple system.

[FirstLast-kviq]

This is the kinda content I subscribed for!!!

[saeedghanbari]

I have a PhD degree in Chemical engineering and I honestly say that you are way more knowledgable than all professors I met in universities and conferences. Academic research at university is 99% ego- driven and BS, just to get a paper published. Bravo man!

[prostosergik]

Expected to see water as the experiment subject. How transparent water is for UV? Can you get skin being submerged into water?

[edgeeffect]

I'm going to be working with UV soon... so this is very useful to know...
The deuterium lamp.... you always have the very best toys!!!

[techninja]

Absolutely love this! Some things I'd love to see: transitions lenses that activate from UV and their change in spectrum transmission over time, also how long thin film sunblock lasts before the UV blocking wears off or breaks down.

[conradinkranz]

this channel is one of my few channels that deserves the notifications on button.

[DyslexicMitochondria]

Yet another amazing video .Really love your channel. As a content creator myself, I highly admire your videos. Keep up the great work.

[S]

makes sense why EPROMs have a quartz window.

[Gymnos]

I think the reason the vellum showed such an odd spectrum is because all the other measurements were taken with background noise zeroed out, but by putting the sample directly against the sensor, it no longer had direct line of sight with the overhead fluorescent lighting. Anyway, very interesting experiments! Thanks again for the great content.

[everythingexplained]

always a pleasure to see you post. high quality content as always.

[tcpipme]

I wish you had tested uv blocking sunglasses, as well as front windshield glass (supposedly uv light blocking). Every video from you is a delight. Thank you for sharing so much of your wisdom.

[slarson]

Great video and a good explanation of some basic spectroscopy. I think the reason why your trick of increasing the exposure time did not work as well as you wished was that you are ignoring the loss/absorption in the fiberoptic cable. If you take your baseline again after increasing the exposure time you should get an accurate reading, assuming that it does not max out the detector.

[realcygnus]

Great info AND gadgetry as of the best yt channels going, always was.

[IbrahimHany]

Amazing as usual. Another interesting tests using this set-up is calculating the optical band gap of any transparent semiconductor, it would simply be blind to all wavelength till it comes to its own band gap, you will see a sharp absorbance, which may change by changing dopants. Not only that, some of them exhibits anisotropy, so you might see different absorbance edges by simply rotating your material (assuming it's a single crystal). What you did in this video with different glasses, is actually a routine test that is done when you use optical filters in laser and florescence experiments to verify the transparency of the filters also. Thanks for such unique work.

[gigglysamentz]

12:57 That's why we used quartz cuvettes to measure the UV absorption of a solution!
For example to see the conversion of NAD+ (no 340 nm absoption) to NADH (absorbs at 340 nm)

[spectroscopy]

I love this because there are millions of people with access to a spectrometer that could do these experiments in 2 minutes. But nobody can make a video about it that is actually interesting to watch, great job!. Although I have to say that some of those spectra are saturated and the lack of collimation optics makes it a little painful to watch at times.

[Voyajer.]

It'd be nice to see you test some welding glass and polarized sunglasses.