Homebrew PCBs

--- In Homebrew_PCBs@yahoogroups.com, "John Myszkowski"
<myszka_us2000@y...> wrote:
> I can shed some light on the bulb wavelength...
> 
> All regular incadescent bulbs have very little UV generating ability. 
> [edited for brevity]
> 
> Incadescent, Halogen bulbs do produce a high level of UV light. 
> [again edited for brevity]
> 
> Fuorescent bulbs. These bulbs, when totally uncoated generate only 
> (Mostly) UV. Extremely little visible light is generated by the 
> fluorescent tube (when uncoated). The visible portion of light coming 
> from the fluorescent tube is generated by the fluorescence of the 
> various powders that coat the inner surface of the tube.
> The wavelength generated by the tube (other than UV) is determined by 
> the composition of that powder.
> ALL fluorescent bulbs generate UV, but the everyday bulbs sold for 
> home use have  a powder coating that both blocks the UV as well as 
> generates only visible "white" light.
> The power of these tubes is determined by the length and diameter of 
> the tube (plasma guide). Therefore, if the tube is the same length 
> and diameter as a normal 40Watt tube, then it is a 40Watt tube.
> 
> 
> John M...

John, 

Thanks for enlightening me! I find it almost amazing with such a clear
disparity
between the possible sources that I really haven't seen such a clear
explanation until now.

So my original question has a definitive answer: Get a fluorescent
black light bulb. Period. End of discussion. It's easy to extrapolate
from your discussion
above that a  BL or BLB fluorescent bulb is coated to filter the
visible light and allow the UV-A through.

I've found an interesting site in my continuing search for info. Of
all places it's a Halloween haunted house type site. It talks about
Black Light sources and has a pointer to what I would now consider the
Holy Grail: compact fluorescent black lights. You can find it here:

http://wolfstone.halloweenhost.com/TechBase/bltgen_BlacklightGeneration.html

So unless someone has compelling evidence to the contrary, I plan to
build my light box using a pair of 12 in BLB fluorescents which are
easily found at the Home Depot or WalMart.

Thanks for the help,

BAJ
> ================