dnelson@mthvax.cs.miami.edu (Dru Nelson) (04/08/90)
Hello,
I purchased an eprom eraser kit at a hamfest a couple years back.
It had the socket assembly, cord, and light. Well, I cut out a section
of a box for copier paper to allow the bulb and it's socket in. I then
put a shoebox inside the box to raise the eproms to the bulb.
It didn't work. After recent postings of bulb types I pulled it
out to check the bulb. It is a F4T5-BL bulb.
Is this the right bulb or is the UV output too low?
Does the surface the eproms sit on have to be conductive?
--
%% Dru Nelson %% Miami, FL %% Internet: dnelson@mthvax.cs.miami.edu %%markz@ssc.UUCP (Mark Zenier) (04/09/90)
In article <1990Apr7.202331.15694@mthvax.cs.miami.edu>, dnelson@mthvax.cs.miami.edu (Dru Nelson) writes: > I purchased an eprom eraser kit at a hamfest a couple years back. > It didn't work. After recent postings of bulb types I pulled it > out to check the bulb. It is a F4T5-BL bulb. > > Is this the right bulb or is the UV output too low? I've seen this published too, which means a lot of people are very patient or authors of magazine articles lie. About 8 years ago, I ran a search for a cheap eprom eraser and and found that there are (at least) 3 types of bulbs that fit into flourescent fixtures. BL or BLB phosphors. This peaks at 350 nanometers and is used for psychedelic posters (the BLB suffix with a dark purple filter) or curing UV sensitive glue or other photochemical stuff. I erased an eprom on a poster light once, but it took 3.5 Days. Sunlamp phosphors. (Suffix unknown). These peak at 300 nanometers. Another posting said that eprom erasure time is about 1 hour. Germicidal bulbs. Not really a flourescent at all, because there isn't a phosphor. A naked mercury arc in a quartz glass tube at 258.? nanometers. I use a G15T8 to erase eproms in 6 minutes. Get a G4T5 for probably $25. markz@ssc.uucp
phil@ingr.com (Phil Johnson) (04/09/90)
In article <1615@serene.UUCP> gbell@pnet12.cts.com (Greg Bell) writes: >jac@paul.rutgers.edu (Jonathan A. Chandross) writes: >>I hate to sound like somebody's mother, but people planning to do this >>ought to be aware of the risks. >> >>EPROM erasers have safety interlocks and leak-proof cases for a very good >>reason -- exposure to UV can damage your eyes. In addition to the UV hazard, >Greg, >Actually, the hazards of low intensity UV lamps are grossly over-estimated >by most laymen. As a health-physicist, I'm aware of the health effects >of many types of radiation and I can assure you that one would have to >work to cause any damage with one of these bulbs. To put this issue in As a health-physicist you SHOULD BE AWARE that UV sources come in two flavors (1) Short wave length - such as germicidal lamps These are fairly safe to view without a filter, such as eyeglasses. (2) Long wave length - such as EPROM erasers These can cause severe damage to eyes if view directly without a filter. This is one of the first safety lessons taught when dealing with UV-based analytical instruments, such as UV spectrophotometers. -- Philip E. Johnson UUCP: usenet!ingr!phil MY words, VOICE: (205) 730-8112 MY opinion!
jac@paul.rutgers.edu (Jonathan A. Chandross) (04/10/90)
phil@ingr.com (Phil Johnson) > As a health-physicist you SHOULD BE AWARE that UV sources come in two flavors > (1) Short wave length - such as germicidal lamps > These are fairly safe to view without a filter, such as eyeglasses. > (2) Long wave length - such as EPROM erasers > These can cause severe damage to eyes if view directly without a filter. WRONG! This is BACKWARDS. Germicidal lamps are EXCEEDINGLY DANGEROUS. They are GERMICIDAL because they DESTROY CELLS. Got it? Repeat after me: If germicidal lamps did not destroy cells they would be useless. If germicidal lamps did not destroy cells they would be useless. If germicidal lamps did not destroy cells they would be useless. Someone said "but I have seen germicidal lamps in barbershops." Germicidal lamps are often placed behind a glass panel. Glass filters out short wave uv, passing the long wave. The blue you see is the long wave radiation passing through the glass. This is not overly harmful provided you don't get too much exposure. Eprom erasers use short wave UV and thus REQUIRE filters. Be very careful -- the cells you save may be your own. Jonathan A. Chandross Internet: jac@paul.rutgers.edu UUCP: rutgers!paul.rutgers.edu!jac
phil@ingr.com (Phil Johnson) (04/13/90)
>(1) Short wave length - such as germicidal lamps > These are fairly safe to view without a filter, such as eyeglasses. >(2) Long wave length - such as EPROM erasers > These can cause severe damage to eyes if view directly without a filter. >This is one of the first safety lessons taught when dealing with UV-based >analytical instruments, such as UV spectrophotometers. I should have had that second cup of coffee before posting this. It is re- versed. Long wave length (near) UV is on the visible light side of the UV spectrum and therefore has a lower energy potential (photon energy~= 4-8 ev at ~120- 700 nanometers). Shot wave length (vacuum) UV is on the X-ray side of the UV spectrum and has a higher and more harmful energy potential (photon energy ~=8-120 ev at ~= 8-120 nanometers). PLEASE NOTE: these values are approximate, so don't flame them. -- Philip E. Johnson UUCP: usenet!ingr!phil MY words, VOICE: (205) 730-8112 MY opinion!