Re: UV water purifier

Bill Kingsbury ( kingsbry@gte.net )
Wed, 30 Dec 1998 21:05:58 -0500

At 05:44 PM 12-30-98 GMT, Alan wrote:
>
>UV emitting phosphors?????
>Correct me if I'm wrong, but afaik, the uv is generated by the
>mercury vapour in the fluoro tube. Normal, *visible* light
>fluoro's *require* phosphors to convert the uv to visible light.
>A uv fluoro on the other hand requires no phosphors, but *does*
>require a quartz glass tube as normal glass blocks the uv.

You may well be correct about the phosphors (or lack thereof).
Then, I wonder why the UV output slowly degrades while the lamp
remains functional ?

And, is there only mercury vapour in the tube, or some additional,
special mix of inert gasses involved ?

--Bill

-------- original message --------
><snip>
>
>>Pete,
>
>>The 'life' rating is for the fluorescent UV light tube.
>>The tube may 'light up' longer, but the UV-emitting phosphors
>>eventually degrade, and usually don't emit enough germicidal
>>UV-B and UV-C for more than 12 - 18 months of full-time use.
>
>