When I examined the tubes, I discovered (with some alarm) the following
label:
Philips F40UVB
[something to the effect of "not for skin tanning, only for
medical equipment"]
On the bottom end (of course) of the box containing the tubes, there
was a label from "Q-Panel Company" saying these were "QFS-40" tubes,
and that they were *not* to be mixed with UV-A bulbs. My best guess
is that they're for some sort of UV disinfection system; given their
power level and surface area, I imagine the UV they produce isn't
all that intense. I can't picture using them for EPROM erasers, for
example (although you could probably zap several hundred chips at a
time, given their size). None of us are showing any sunburn so far,
after a few minutes' exposure. :-)
Can anyone identify these bulbs, verify that they really are putting
out UV-B, provide any information about wavelengths and flux levels,
or let us know if we'll all be blind and cancerous in a year or two?
I've checked Philips' web site, and found some pictures of "full-body
solaria," but no information on tubes (and certainly no safety infor-
mation). These tubes are several years to several decades old; they
were left by people who spent decades scavenging cast-off items from
around the county.
Thanks in advance...
--
-jeffB (Jeff Brandenburg, Lancaster, PA)
> A friend of mine came across a box of what he thought to be standard
> 40W, 48" [standard in *this* country] flourescent tubes. When he tried
> them out (in a fixture designed for normal flouresents), they gave the
> characteristic lavender glow of a "blacklight" (UV) tube.
I cannot identify the markings, but if they are clear tubes with a
characteristic mercury vapor blue glow, you better take extreme care.
You don't want to find out the hard way with respect to blindness
and cancer. I would strongly recommend NOT operating them unprotected
until and if you find that the wavelengths are safe.
Medical applications of such lamps often involve something ending in
-ide which means killing which means harmful to living tissue.
--- sam
<snip>
>I cannot identify the markings, but if they are clear tubes with a
>characteristic mercury vapor blue glow, you better take extreme care.
They looked like conventional flourescents -- an opaque (okay,
translucent) white coating inside the tube. The glow wasn't like
mercury vapor (although I confess I haven't looked at an unshielded
mercury tube).
>You don't want to find out the hard way with respect to blindness
>and cancer. I would strongly recommend NOT operating them unprotected
>until and if you find that the wavelengths are safe.
Oh, don't worry, we won't. :-) It's hard for me to imagine any tube
labeled "UV-B" being "safe" in the sense of "go ahead, pop it into your
overhead fixture and gaze fondly." If they're putting out enough flux
to be interesting as, say, a chip eraser (chips 1 meter long?!?), I'd
put them in a *very* light-tight box.
For what it's worth, still no sunburn. We also didn't smell any ozone
while they were operating. As I said, I don't think they produce a
very intense flux -- but I also realize that UV-B is harmful long
before you smell the ozone. Or feel the burn. My eyes aren't the
sharpest, but they're the only pair I have, and I protect them.
>Medical applications of such lamps often involve something ending in
>-ide which means killing which means harmful to living tissue.
Yes, but is it harmful like "germicidal soap," or like a Therac? :-)
Thanks for the reminders, and if anybody else can help us ID these,
we'd sure appreciate it...
I dug through Westinghouse's spec sheets at a lamp supplier many years
ago. There are a couple of phosphors that emit UV. One of them peaks
at 350 nanometers and you can get it with or without the purple filter.
With the purple filter, they're what's used for dayglo ("neon" for
anyone under 35) posters. Without the filter, they're used for various
photochemistry things like exposing silk screen masks and curing UV
sensitive glue. There is also a phosphor that peaks at 300 nanometers
and is sold as sunlamps for tanning beds.
Back in my starving microhacker days at the dawn of the era, I used a
poster lamp to erase a 2716 EPROM. It took 3 1/2 days. I hear the
tanning lamps will do it in about 45 minutes. And a germicidal lamp (no
phosphor just a clear tube) does it in about 3 minutes. (Germicidal's
have a spectrum line at 258 nanometers).
So fire it up and try to erase an EPROM. If it doesn't do it in a
couple of hours, It's probably a 350 nanometer tube. Or call up
a specialty lamp distributor and see if they have the spec sheet.
I found the spec sheet that I got for the 350 nanometer lamp I have.
Since UV-B is supposed to be one of the ranges that will tan people,
and the output spectrum chart for this lamp also shows "erythemal
effectiveness" which has a peak at 300 nanometer and another at 250,
I suspect that you have 300 nanometer range lamps.
Mark Zenier mze...@eskimo.com mze...@netcom.com
>>On the bottom end (of course) of the box containing the tubes, there
>>was a label from "Q-Panel Company" saying these were "QFS-40" tubes,
>>and that they were *not* to be mixed with UV-A bulbs. My best guesse
>>
>>Can anyone identify these bulbs, verify that they really are putting
>>out UV-B, provide any information about wavelengths and flux levels,
Fluorescents putting out low levels of UVB are used as overheads for
iguanas and other pets which need 310 nanometer light for production
of vitamin D from cholesterol-type compounds in their skin. Judging
from the following post from George, this may not be the original
intent of the bulbs, but UVB bulbs are made by Durotest, Zoomed and
others in the reptile business. You may find something close in pet
stores under the name Vitalight (Duro) or IguanaLight or Reptisun
(both ZooMed).
-----------------------------------------------------------------------------
In <49lr0m$2mg...@com.infinet.com> gtb...@infinet.com (George Butts) writes:
>We used tubes of this type in common accelerated aging cabinets which
>...
>Q-Panel was/is a major supplier of test panels and other pieces/parts for
>this type of material testing.
My understanding is that manufacturers have a problem coaxing
sufficient levels of 310nm light out of a fluorescent, so I'd
like to find out if these bulbs have a substantially higher
level of UVB output.
Do you know how much UVB the Q-Panel bulbs put out?
Does anyone know a convenient way to measure UVB output?
Regards,
Mark Garvin
>So fire it up and try to erase an EPROM. If it doesn't do it in a
>couple of hours, It's probably a 350 nanometer tube. Or call up
>a specialty lamp distributor and see if they have the spec sheet.
Y'know, Mark, I've been trying to figure a good way to measure
UVB light output. Sounds like this should provide a clue, at least!
Now I know why I saved those 1024 byte EPROMS.
Any idea of the rated optimal wavelength for erasing an EPROM?
Here's another question: did you try leaving your eproms exposed to
sunlight? Wouldn't that have been effective?
People on newsgroups dealing with pet lizards (iguanas, especially)
have been debating UVB-output questions for MONTHS! Everyone is
trying to figure out relative merits of various brands of UVB bulbs
compared to natural sunlight.
This is because iguanas need UVB at around 310 nm to metabolize
sterols into vitamin D3. Lots of animals have been getting sick
due to lack of natural sunlight when in captivity.
Any info on the above would be great.
Mark Garvin
In Western Washington???????? What's sunlight?
(Actually, Intel sez that it would take 2 weeks, so I never tried.)
And the only spec I've seen in the databooks uses the 258 nanometer
mercury line. Might be worth asking in sci.engr.semiconductor.
Mark Zenier mze...@eskimo.com mze...@netcom.com
[re: UVB lights]
>They are used
>by the Russians in Siberia in the half-year nights to give their kids
>enough vitamin D in their skin, but even they wear protective goggles.
>Saw this on TLC or Discovery the other night. I'd think they should
>simply send cod-liver oils or vitamins, but the Russians think that
>light is "healthy".
In reptiles, there is some debate whether vit D will be effective
when ingested. Current 'speculation' has it that UVB exposure is
necessary. I don't think there is any final word on this yet.
Mark G.
--
-Steve Walz rst...@armory.com ftp.armory.com/pub/user/rstevew
also mirrored at: ieee.cas.uc.edu/pub/electronics/faq/ftp.armory.com
and in Europe at: ftp.cised.unina.it/pub/electronics/ftp.armory.com