# Germicidal UV bulbs



## NewBie (Oct 8, 2006)

I'm looking for something like this product, does anyone know where to get them at a lower cost?

http://www.donsbulbs.com/cgi-bin/r/b.pl/gph|254mm|t5|vh|2pin~atlantic-ultraviolet.html


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## Handlobraesing (Oct 8, 2006)

NewBie said:


> I'm looking for something like this product, does anyone know where to get them at a lower cost?
> 
> http://www.donsbulbs.com/cgi-bin/r/b.pl/gph%7C254mm%7Ct5%7Cvh%7C2pin~atlantic-ultraviolet.html



Have you called Pacific Lamp Wholesale in Beaverton? By similar, I'm not sure if you need the size and type in the example or a germicidal lamp in general. 
G15T8 in standard 15W T8 shouldn't cost more than $40.


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## Ken_McE (Oct 8, 2006)

I don't see the part where he specifies output in Nanometers.


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## NewBie (Oct 8, 2006)

The wavelength is short enough that it produces ozone as I understand it, and it uses a quartz envelope to allow the "short" UV thru, which normal glass blocks.

Going by memory, I believe it was 265mn or 290nm, but I don't recall now.


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## PhotonWrangler (Oct 8, 2006)

The newer germicidal envelopes claim to filter out most of the ozone-producing wavelength while allowing other germicidal wavelengths to escape. I believe the older quartz bulb envelopes produce more ozone.

BTW I agree with Handlobraesing; you shouldn't pay more than $40 for one of those lamps. The last time I purchased something like that from bulbs.com it cost me around $35.


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## Handlobraesing (Oct 8, 2006)

NewBie said:


> The wavelength is short enough that it produces ozone as I understand it, and it uses a quartz envelope to allow the "short" UV thru, which normal glass blocks.
> 
> Going by memory, I believe it was 265mn or 290nm, but I don't recall now.



The usual germicidal bulb is ~250nm, but if you're using it to make ozone, you need something made with glass that passes ~185nm. 

Most germicidal lamps are designed to not let 185nm out to avoid ozone.


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## NewBie (Oct 8, 2006)

No Duh.

Thats why i was talking about quartz.

However, there are some special glasses better suited, but highly expensive. I really don't need you to explain this stuff to me.

Since you appear to be knowledgeable about bulbs, could you actually point to a 14W bulb that is lower cost, that will pass wavelengths which produce ozone?

So far your examples have been useless to me.

Typically low pressure argon is used to stimulate the mercury vapour. It is this process which generates ultra violet radiation mainly at 253.7nm (germicidal) and shorter wavelengths (such as 185nm- ozone producing). Atypically quartz is used, as it passes the UV light better than other similar cost glasses. The choice will vary depending on which wavelengths you really want.

Often with these sorts of lamps, they are mis-represented as hard quartz, and one can see the soft quartz that was used, turning black itself, not from deposits inside.

"Fused Silica" aka quartz, comes in several grades. One that would pass 185nm well is known as *Full Spectrum Grade Synthetic Fused Silica (KI*), a plot is shown here:
http://www.sciner.com/Opticsland/FS.htm


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## Handlobraesing (Oct 9, 2006)

NewBie said:


> No Duh.
> 
> Thats why i was talking about quartz.
> 
> ...



What about this one? $35
http://www.1000bulbs.com/product.php?product=3997


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## NewBie (Oct 9, 2006)

That works, thanks.


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