Re: [at-l] UV pen

["W F Thorneloe, MD" <thornel@ibm.net>]

At 03:10 PM 7/28/1999 -0400, David  F. Addleton wrote:
>.... I will select the stream from which I will drink untreated water. You 
>will drink only boiled or pur filtered water. If I get sick and you don't 
>you'll have sufficient empirical evidence to state that the pur filter works.

No, with an "N=2", there isn't enough population to avoid a number of 
variables including 1) where either of you drank 3 weeks ago, 2) a Pur 
filter that is in Liter 2005 of a 2000 liter lifespan; 3) other random events.

You make SunTea with tea in a jar, simply by heating the water in the 
enclosed jar, and consuming it before the funguses and nasties on the tea 
bags ever get a chance to get a good culture growing. UV has little to do 
with it, and is probably absorbed by the container. Your rule of thumb for 
safe water that is above treeline and remote from other animals and humans 
has little to do with UV exposure. UV is an effective non-chemical means of 
sanitation, but energy intensive, and possibly weight intensive. I suspect 
it may also be labor intensive for the need to expose as much of the water 
as possible to the flow of water.

In reviewing the websites yesterday, it appears that the UV in industrial 
and residential settings are from light tubes in a metal box through which 
the water must pass before consumption. The involved surface area is for 
the light source, not the water. I am more suspicious that the light pen is 
an ineffective means of water purification, unless some means of forcing 
each drop of water past the light can be arranged. I suspect a pump that 
uses the light source instead of a filter would work, but would that be 
lighter and more convenient that your Sweetwater or my PUR? I don't think so.

If these folks can provide proof and a competitive advantage to current 
filters and Iodine, I will be in line at REI for one for both of my known 
friends. Otherwise, they're stuck with another chintzy Photon light!

OrangeBug
Atlanta, GA
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