Question about UV

[**DONOTDELETE**]

Hello,

I just got my third Arc AAA, a UV model. I got it to check the UV security features on NYS driver's licenses. It doesn't, and I'm curious as to why.

It will illuminate the security strips on US currency, as well as the UV features on certain credit cards, so I know there was no mix up with the packaging (that is, it IS a UV.) -But on the licenses, nothing. I know the security features work, I've seen them. I even stopped in at one of those junk stores at the mall that sells halloween stuff, blacklights, etc. to show my wife what I was talking about and there was no problem seeing it there.

Anyone have any ideas what's up? I'm going to return it I suppose, but then the question becomes which small light will do what I want?

Ideas and/or experience needed. Thanks

 

[Roy]

My AAA UV does the same thing. It probably has to do with the frequency of the light and the fact that what we're trying to see in the DL is behind plastic, which is probably absorbing the UV from the AAA UV. A stronger source of uv is probably what is needed to check the DL.

 

[**DONOTDELETE**]

Any suggestions though, something "Arc-like" that could be carried unobtrusively?

 

[sunspot]

Photon has a UV model.

 

[**DONOTDELETE**]

I was thinking about that, but I'm pretty sure the Arc is much brighter. So, if it's a brightness problem, the Photon won't do it. However, I also think that they're slightly different wavelengths, so if that's the issue, the Photon may be the answer.

I'm hoping someone's tried both for my purpose.

 

[Tomas]

There are many slightly different wavelengths in the "UV" portion of the spectrum, and different materials respond to different wavelengths. The "blacklights" at the mall produce a much broader band of wavelengths than an LED will.

An LED produces a very narrow band of UV centered at one particular wavelength. If the material you are trying to get a response from does not respond in that narrow band, you will not see what you want to see.

I have an Arc AAA UV that works amazingly well on many materials and dyes. As expected, it does not work at all on some UV reactive dyes.

I also have two portable florescent "blacklights" with bulbs from different manufacturers. They cover a much broader bandwidth than any of the UV LEDs do, but even they have their limitations: They are each centered at a slightly different wavelength and some things will respond to one and not the other, and several things that respond strongly to the Arc AAA UV don't respond at all to one of them.

The output of the Arc AAA UV LED appears to be centered at about 390nM, as does one of the florescents. The other florescent appears to be centered at a somewhat shorter wavelength, and excites different UV reactive objects most strongly.

Hopefully, that made some sense . . . *sigh*

 

[**DONOTDELETE**]

bttt

 

[Darell]

I have a couple of different UV LEDs, but I don't know what I'm looking for on my license

I have a CA DL - anything exciting there to see?

I have some UV pens, and some don't show up at ALL under the Arc UV while the other pens work perfectly.

 

[vcal]

Originally posted by darell:
I have a couple of different UV LEDs, but I don't know what I'm looking for on my license

I have a CA DL - anything exciting there to see?

<font size="2" face="Verdana, Arial">Nothing but a measly hologram on ours, Dimmer....
(I've got lotsa UV illuminators
& could find nada on the CA DL)

 

[**DONOTDELETE**]

Hello,

For what its worth I have an AZ license and we have a UV picture of "the great seal of the state of Arizona" on the front which illuminates well.

I took a plastic bag (like a ziplok or glad) and folded it in half (4 layers) then tried to illuminate the license, it still works fine.

The plastic on your license is probably not soaking up the UV.

Thanks

 

[OrBy]

I wont go too far into this but the short of it is there are newer and older gen arc aaa uv's.
The olders ones used a weaker but lower nm led that lit some things up better. The newer one uses a more powerfull led but its also a higher nm uv.
(old was like 1-2mw 370nm nichida, new is like 12mw 390nm cree i think)
Doing some searches on the board with get you more info - as well the old arc site had this info right on it for a while.
If anyone remembers the solid numbers feel free to correct me/elaborate further.
The old one was darn invisable - the new one is a very nice violet color. (never look into these things directly without protection!!!!!!!!!!!!!!!)

 

[Graham]

I have one of the older Arc AAA UVs, and really like it - I prefer it to some of my other UV LED lights which use the more powerful, more violet LED.

The older one has almost no visible light output, and is barely noticeable when on and looked at from the side. But it has a nice beam, and lights things up really well. It is a great 'stealth' light, in that you can use it to look around in the dark (at things that fluoresce, anyway), with no peripheral light to disturb others.

Graham

 

[fluorescent]

how can you tell if you have one of the older models? I just received my UV and picked it up because on the web site it said they were using a new brighter (was 1mW, now 12+mW), wider angle (was 10 degree, now 30 degree) LED as of 2/1/02!
stronger, more powerful LED in them. Do the newer models have the gold coating on the inside? The reason I ask is because the output seems rather weak. BTW the package that the light came in says 10 year warranty, the web site says 1 year...

 

[INRETECH]

If you would like to experiment more with UV inks/dyes, my friend Leo designs all sorts of neat stuff

He just released a waterbased waterproof dye that is invisible, until you hit it with UV and then it shines Milky-Blue

He is really great to work with, you simply tell him what type of ink/dye you are looking for with what properties you want, and he will custom design it for you

http://www.paintspecialtieslaboratory.com/

 

[James S]

I picked up a couple of UV led's recently that claim to emit at 400nm, they are quite visible and I've been careful not to shine them at my face while they are sticking out of the breadboard.

Last week I also placed an order for a couple of samples of the new glow powder. I'm really excited to get these 2 things together! I can't find any specific info on the glow powder as to the ideal UV frequency to charge it with, so I'll just try these and see what happens.

I'm also interested in what kind of protection is necessary. If you can just get these LEd's in a regular flashlight then they can't be very dangerous to your eyes? If I were to build something out of them what should I use to stop the UV from getting out where it could hurt people? Is there some kind of coating or plastic sheeting that could be used to stop it without reducing the light from the glow powder too much?

Thanks,
James

 

[Graham]

Originally posted by fluorescent:
how can you tell if you have one of the older models? I just received my UV and picked it up because on the web site it said they were using a new brighter (was 1mW, now 12+mW), wider angle (was 10 degree, now 30 degree) LED as of 2/1/02!
stronger, more powerful LED in them. Do the newer models have the gold coating on the inside? The reason I ask is because the output seems rather weak. BTW the package that the light came in says 10 year warranty, the web site says 1 year...

<font size="2" face="Verdana, Arial">See this thread for some extra info.

I understand that the 1 year warranty is due to the shorter useable life of UV LEDs.
If you got your UV Arc AAA recently, then it should be the newer type - Arc stopped producing the old one several months ago.
Quite simply, if you shine your UV arc on something and see a lot of purple/violet light, you have a newer one. If you see hardly anything (except glow from fluorescent colours) then you have the old one.

Graham

 

[**DONOTDELETE**]

My AAA was extremely bright (relatively speaking, of course) as far as visible light goes. I had wondered about that too, having searched here and read over and over how little visible output there would be. This thing could easily have served as a regular small flashlight.

 

[sunspot]

James S. Glow powder is best charged up by florescent light.
May I asked where you got your powder?

 

[James S]

I don't think that embedding a fluorescent in it is an option, but I'll try that too.

I ordered it from http://www.readysetglo.com/ (don't add the "w" to the glow or you get the "Girls Leading Our World" website and an opportunity to "Win The Ultimate Sleepover!" which is great, but doesn't glow.)

I ordered it several days ago. I did get a receipt email, but so far no notice of shipping and nothing has shown up at my door. However given standard UPS shipping I think the earliest it could arrive is this coming monday. I ordered some of the aqua and the red and will certainly post about it once I've had a chance to play with it;)

Thanks,
James

 

[sunspot]

Ooops. I was thinking only charge up, not having the charge source with the GID. In that case, the UV is the best choice.
Now that I finished my dual LS, stained glass lantern, I am starting on a light box that uses UV LED's and mount Uranium marbles on top.