What does everyone do with their UV LEDs?

A few purchases ago from on online merchant, I snatched up a couple key-chain "UV" led key fobs as an add on to my growing collection of regular LED lights. They were pretty cheap and bought them on a whim. I did a quick search of CPF and was alarmed to read (an older archived post started back in '01) that they might be harmful!!! If this is true, why are they being sold? Or are the ones I bought just a glorified black-light LED key chain light? The brand name on them is TITANIUM and they appear to be 5mm LEDs that are clear when off and a deep purple when on. Anyone else have one of these UV LEDs? And what do you use them for? I've found that there are invisible markings on the back of my DrLic and my visa card. A novilety at best.

I used to work for a company that built stainless steel silos. We would TIG weld a thermal dimple jacket on it and then pressure test it with a liquid that glows under UV light. We would come back in 4 hrs and look for little spots.

So.................that would be one way to use a UV LED.

Most of the generic UV lights are fairly harmless. They are long wavelength UV along with a good dose of "purpleish". UV LED's that have a very short wavelength can be harmful, but they are usually very expensive, and such lights that use them are well marked with warning labels.

I need to amend my post....I wasn't thinking, a true UV led would not be visible to the human eye, DOH!!! Ryanrpm, your use for a UV LED is useful. Thanks for your reply. EDIT **Your reply is helpful too, Marduke, thanks.

There are lots of use for UV. They will fluoresce certain insects, minerals, ink, logos, bodily fluids, etc.


In industry and professional use, they can be used for crack inspection (non-destructive evaluation), leak inspection (see above), cure UV sensitive adhesives and paints, disinfect water or equipment from microbes, etc.

Next time you stay in a hotel or motel take a UV flashlight in the room with you. You might be surprised at what you see.

Ala CSI style? D@mn! Now I need a bigger UV led than what I have now. There goes some more $$, LOL.

To tag on to what Marduke was saying about shorter wavelengths being harmful, here is a short thread concerning some info on it.

http://www.powerledlighting.com/bbs/viewtopic.php?f=9&t=9

Marduke said:

In industry and professional use, they can be used for crack inspection (non-destructive evaluation), leak inspection (see above), cure UV sensitive adhesives and paints, disinfect water or equipment from microbes, etc.

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Can they reveal fingerprints on metal, plastics and shiny surfaces?

kramer5150 said:

Can they reveal fingerprints on metal, plastics and shiny surfaces?

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Not by themselves, you would need a reagent designed for it.

kramer5150 said:

Can they reveal fingerprints on metal, plastics and shiny surfaces?

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The common method is to use a dusting powered (regular old police style fingerprint dust) that has a dye added that fluoresces under UV to make prints stand out.

I use mine to charge the lume on my watch before going to bed...

As geocacher, I would need one for those rare caches, where the owner has written requested numbers for an unknown cache in the logbook, with a special ink that you can only see with UV.

Until I have one, there's another solution though : Ask somebody you know and who has an UV light and who was there already for the numbers! That's cheaper...

I use one to find stains in carpet, tile, etc. Walk around the house at night with a strong UV light and you can find all kinds of interesting things
Interesting note: After a recent visit from the grand babies I did a night time carpet check and found a new stain in my living room carpet. I decided to shampoo the carpet but I was out of regular shampooer soap so I used a little bit of laundry detergent. It worked fine, but I know laundry detergent has stuff added to it that makes clothes just slightly florescent so they seem brighter and I wondered if this would make my carpet look brighter under the UV light.
That night I checked the carpet with my UV light and the overall carpet was not florescent, but the stain was now much brighter than before and I even found a few more stains that I could not see before. The laundry soap enhanced the florescent properties of the stains.

Last week a TSA employee was using an Inova X5 UV to check people's IDs at the Baltimore airport. Hadn't seen that before...

I use one at work to check Michigan driver's licenses.

Hunting!
I use mine all the time, as a bow hunter I have found the light to be worth it's weight in gold to locate lost arrows, it will light up fluorescent fletching like a lighthouse! I also use it for walking in to a stand at night, using small chunks of fluorescent trail tape, at night in the woods, even a cheap UV light will make those things stand out among everything else.

http://www.youtube.com/watch?v=CqkG3CqPbQk

Funny clip with UV
Not work safe, Sorry for not posting that before.

Previous clip is not work safe...

Here is something else outrageous:

http://www.youtube.com/watch?v=BQe045Doytk&NR=1

jbviau said:

Last week a TSA employee was using an Inova X5 UV to check people's IDs at the Baltimore airport. Hadn't seen that before...

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They've been doing that for a while now at all the airports I've been to recently.