Homebrew PCBs

----- Original Message ----- 
From: "Andrew" <andrewm1973@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Friday, September 15, 2006 10:03 AM
Subject: [Homebrew_PCBs] Re: UV exposure boxes


>> >> Me wrote:
>> >> BTW - the GT tubes are no good for PCB
>> >> exposure either.  They are too short a
>> >> wavelength. They are only good for
>> >> EPROMS, killing bacteria, making ozone
>> >> and going blind.
>> >>
>> >> BL and BB tubes can obviously be looked
>> >> at with no ill effects apart from those
>> >> you would get from drinking to much while
>> >> sitting on the patio or at the disco.
>
>> > Leon wrote:
>> > The germicidal tubes work fine for me.
>
>> Then Leon wrote:
>> Sorry, they are not GT (I used to use them
>> for EPROMs) - they look like white
>> fluorescent tubes.
>
> The ones that look white when they are turned
> off are the BL (Black Light).
>
> The ones that look purple when they are off
> are BB (Black Light Blue).
>
> The GT ones are clear when they are off.  I
> think that the GTs are also not made from
> normal glass as it blocks too much short UV.

I think that is the case. That's why ordinary glass is OK for UV exposure 
boxes, it doesn't absorb the longer wavelength UV. I used Perspex at first, 
thinking it mattered.

Leon