RE: [at-l] UV pen

["McBride, James" <mcbride_j@lxe.com>]

David,

Thanks for the response and keep on researching.

One of the main reasons I'm skeptical is the seemingly misleading way in
which they presented the specs for the unit. And by the way I have not read
them myself - I'm going by what you said. The energy required to purify
water is given as between 16 and 40 mw/cm^2. The pen is then listed as
having a 5w light source. The obvious inference to be made is that the light
on the pen is putting out hundreds of times more energy than necessary.
Sounds great, right? But the problem is that we don't know how much of the
5w output is in the appropriate uv wavelength range for purification. Also
we have no idea about how the optics in the pen spreads the light out. So
what we have is 5w of which we have no idea how much is in the uv range and
we have no idea of the area this light is spread out over.

This appears to me to be purposefully misleading advertising. Why not
specify it as follows:

The steri-pen puts out 100mw/cm^2 when held approximately 10cm from a water
source.
Or something similar to this.

What they did reminds me of the way they used to advertise ultra-cheap power
amps for car radios. They would specify a tiny unit at 100w and it was
obvious to anyone that it couldn't put out 100w of power. They were adding
the input AND output powers together and saying the amplifier was so many
watts TOTAL power.

By the way I'm not a physicist. I only have a BS in Physics. You have to
have a Phd to be a real physicist. I have crossed over to the world of
engineering whree you can actually get a job and make money :-)

Jim McBride





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