Real UV flashlight

[Atomicrox]

That's why I never actually bought it.. I got intrigued with the short wave minerals, though. If they do light up with regular blacklight the LED flashlight Cyparagon suggested should work.

 

[AUS]

I bought a 365nm "1 watt" ultrafire off eBay. It was a bit dull with a single 18650 (which was probably normal according to cyparagon's post) so i put two 3V CR123's which made it warm up fast and killed it. I bought another LED and found the LED was fine, driver had died. I took the driver out of a green LED Drop in (they were identical drivers & components). I now have a spare LED.

I have an orange pencil I found at work that flouresces like a beacon its almost too bright to look at. The standard Australian power outlets have a red dot to indicate 'on' they glow like crazy in either UV or with a 405nm laser. Laundry detergent glows well and I can see marks on my carpet and kitchen walls too.

The 365nm ones are harder to find and more expensive than the 385-395nm ones.

 

[Seoul_lasers]

Those professional Shortwave lamps use the same germicidal bulbs, just that the window
is woods glass. The glass does filter out some of the 400nm range as well as the lower 200nm range. 280 – 100 nm is UVC, indeed right.
Woods glass clips pretty much 200nm and below. The MUV is what we need for shortwave viewing. That was my mistake.

 

[AUS]

Interesting.
I have a yellow envelope that my 365nm torch flouresces but a 405nm laser won't.

 

[scopeguy20]

DIY are the best!

 

[Bionic-Badger]

Yeah, if you want to DIY, you can get those 365nm LEDs from Mouser.com. I'd personally just go with a fluorescent lamp though, as they put out a ton of light for far cheaper. I think UV output for those LEDs is like 3-5% efficient or something.

 

[Cyparagon]

The efficiency is about the same for fluorescents though. They have higher output, but they're also much higher power. A standard tube is 15W. Another disadvantage is the inability to put the light in any sort of "beam," which may ultimately lead to a lower power density.

 

[LarryDFW]

I build UV flashlights commercially.

This is the current model that I produce:

I produce it with both 365nm and 395nm UV LED's.

Heatsinking is the biggest challenge with high power.

In most applications the 395nm version performs the best.

It has far more power than the "toy lights" offered by DX.

LarryDFW

P.S. As Cyparagon mentioned, beam power density is the key parameter.

 

[Atomicrox]

I already ordered the other one from KD but out of curiosity how much would cost a 365nm one?

 

[LarryDFW]

I already ordered the other one from KD but out of curiosity how much would cost a 365nm one?

The 365nm light with 2800mah Samsung cell is $199.

The 395nm light with 2800mah Samsung cell is $189.

The 365nm LED has ~ eight times the actual 365nm UV output of the "1 watt" Ultrafire 501 series lights.

It also has much better reflector system,

resulting in better-focused beam characteristics.

LarryDFW

 

[Atomicrox]

Cool, thanks.

 

[Atomicrox]

My flashlight arrived today!
The host is very nice and sturdy. It's very well finished for the price
It's brighter than I expected and certainly not 405nm.
Eats those 16340's faster than my 445nm 1.1W laser. Damn!

Some things fluoresce more with it than with my blu ray laser and some fluoresce less.. Plants don't have the red fluorescence that they have with the laser. Bill markings are way clearer with the flashlight!
Some things fluoresce slightly different colors as well!

I didn't take a picture but the "dot" from mine looks very different than the pics from piferal and Cyparagon. Mine looks a white-yellowish color when I target most non-fluorescent things.
I'm not sure if that's the LED's visible light "tail" or a weak fluorescence. Any ideas?

 

[Cyparagon]

Unless it drains batteries faster simply because you have it on longer, something might be wrong. It should be drawing about a tenth what your 445nm laser is drawing.

The yellow will be some of both. Does it appear yellow when you look into it?

 

[Atomicrox]

Measured and with 2x16340 it pulls 680mA, which isn't much lower than the 870mA the laser gets. With 1x18650 it's barely visible and draws 40mA. I've attached a "dot" shot at a white wall (looks less greenish IRL) and a shot of the LED running under one 18650.

It does look yellowish when I look into it. I've determined the yellow is indeed visible light, since placing yellow goggles in front of it will let most of the yellow pass but cuts the fluorescence totally.

I've also compared it to a money detector tube and both seem to fluoresce the same things, while the 405nm laser fluoresces some things differently. The flashlight is actually brighter than the tube but also seems leak a lot more visible light.

 

[Cyparagon]

Sounds like the driver is dying. LEDs can turn funny colors when you over-drive them.

 

[Atomicrox]

Damn, the site says 2x16340 are fine. Anything I can do about it?