From: SFPhysics@aol.com
Date: Tue Jan 28 2003 - 10:26:31 PST
From: SFPhysics@aol.com Message-ID: <4c.173e670b.2b682557@aol.com> Date: Tue, 28 Jan 2003 13:26:31 EST Subject: Sterilizing Cabinet details
<<
>Thanks for the details. Here are some additional questions:
>1. Is there a reason that you used a metal cabinet instead of wood?
>2. Where did you purchase the germicidal UV lamps?
>3. How many lamps did you use in the cabinet? One for each rack of goggles?
>4. Dumb question . . . What is an interlock? How did you wire it to the
timer?
>5. Does it matter how the goggles are oriented inside the case? IE,
>will the UV kill germs at any angle in relation to the goggles?
>Thanks a lot!
> Geoff
>>
Greetings again Geoff:
1) A metal cabinet can take the UV and reflect the UV around inside better
than a wood cabinet, even one that is painted. Now you could put aluminum
foil glued inside the wood cabinet and that would help. As it was I choose
the metal for ease of mounting components and because most of the wood
cabinets are cheaply made.
2) I purchased the UV germicidal lamps from a medical supply store but they
are standard lamps and can be found in food industry/restaurant supply
stores. These are the same ones used in most meat markets to attract flies
to a killing grid and to kill bacteria on working surfaces.
3) I used two 16" lamps vertically mounted on the sides towards the front of
the cabinet. The lamp mounts were purchased at Home Depot since the UV lamps
are the same electrically as the normal fluorescent tubes (in fact UV
germicidal lamps are simply regular lamps without the fluorescent coating).
The shelves were removed and the goggles were placed on pegs. This way the
UV was distributed evenly over the goggles surfaces.
4) No such thing as a dumb question, only dumb answers! The interlock is
simply a series switch that won't let the lamps light when a door is open or
slightly ajar. It is wired in series with the timer so that if any door is
not 100% closed then no UV will be generated It is a safety feature to
prevent accidental UV exposure from the mercury vapor/argon lamps which can
damage human eyes.
5) The idea is to have the UV bouncing all around the inside of the cabinet
so there are no shadow zones. The surfaces are all internally reflective so
the UV levels are high enough to do the germicidal work in just a few minutes
between classes. Thus, viral and bacterial infections are not passed along
to the next goggle user! I also cleaned the goggles periodically with ethyl
alcohol to remove human contaminants.
Hope this helps,
Al
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