You've wandered directly into my wheelhouse in this discussion. I have worked
with very high power medium pressure mercury arcs literally every working day
for the last 25 years.. Early on, since I tend to be rather careless, I would
develop UV conjunctivitis, which feels like someone dumped a handful of sand
into your eyes. Over the years I have developed a resistance to this effect.
Perhaps it's a "corneal suntan". You can get special safety glasses to absorb
the damaging wavelengths, but they are not inexpensive. Most if the glasses
sold for this purpose really don't work. You have to interpose the lenses
between the light source and a fluorescent material to see if they are
effective. All of the inexpensive ones I have tested fail. This is just the
usual *** cheap crap that they will lie about to get you to buy it. It's
how we got to our present situation of debt and disease.
The problem with "about a million 254 nm UVGI systems" is that they are mercury
arcs. They are virtually all made in *. They are suspiciously inexpensive,
even for *** product. This makes me wonder if they are borosilicate tubes
rather than the fused quartz required to pass 254 nm. If that is the case, you
would be buying something that would have several of the irritating UV
wavelengths without the benefit of the virus killing 254 nm. *** sellers
will lie about practically anything to get you to buy. I don't have one of
these inexpensive UVGI devices to test, but I think I might buy one just for
that purpose.
Probably, all the 222 nm excimer lamps are made in * now. There are U.S.
companies making and selling products using such bulbs, but I think all the
tubes themselves are made in *. We really need to pull our heads out.
On Wednesday, April 22, 2020, 12:13:51 AM UTC, Terry Blanton
wrote:
On Tue, Apr 21, 2020 at 3:32 PM Michael Foster wrote:
Yes, 254 nm is an excellent virus killer. However, unlike 222 nm, long term
exposure to 254 nm can cause damage to the eyes and skin. As Jonathan Berry
points out 222 nm won't even penetrate the water film on your eyes.
Well, there's only about a million 254 nm UVGI systems out there and they are
quite inexpensive. But, if you feel compelled to stare at the photon source,
spring for these $10 safety glasses. They meet CSA Z94.3 standards.
https://smile.amazon.com/gp/product/B000USRG90/
Virus-free. www.avast.com
