black light

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I saw a pocket flashlight in a hardware store yesterday,  
it shines UV.  Such a package is new to me.

What is it good for?  What's inside?

And whence the origin of the term 'black light'?  
I recall days gone by, the wall posters were popular, is  
that still in fashion?

--
Rich

Re: black light
On 11-2-2019 23:53, snipped-for-privacy@gmail.com wrote:
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Checking bills for forgery.
Checking minerals for fluorescence.
Checking bedsheets for eh. you know eh...

   What's inside?
Either a LED or a small fluorescent tube(got one with that).
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You cannot see UV light, so they called it blacklight.
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?????
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Re: black light
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currency checking.
reading UV security marks.
curing UV-cure resin.
erasing EPROMs.
searching for lost flourescent items.
making candy glow wierd colours.
etc...

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a UV light emitting diode.

--  
  When I tried casting out nines I made a hash of it.

Re: black light
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One would hope not.  The UV band is generally split into three, UV
A, B and C.  To erase EPROMS you need the UVC, most blacklights,
most blacklights, especially the commodity devices for banknote
checking, UV curing etc are UVA.  UVA is what those insect killing
lamps you see put out, albeit generally in white rather than
blacklight form.  UVC is much shorter wavelength and a massive risk
to your eyes if exposed to it.  Think the kind of masks used for
arc welding.  There is a reason EPROM erasers invariably have safety
lock that cut out if you open the drawer when it is operating.

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Could be.  Could be a small fluorescent or a filament bulb.

--  
Andrew Smallshaw
snipped-for-privacy@sdf.org

Re: black light
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ok. not EPROMs then.

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I have a LED one here. It's I0 cm long so definately pocket sized.

https://www.aliexpress.com/item/UV-Flashlight/32831334716.html

--  
  When I tried casting out nines I made a hash of it.

Re: black light
On 2/11/19 5:53 PM, snipped-for-privacy@gmail.com wrote:
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Hello, and not knowing the footprint of what you saw, I've got small,  
handheld a 25 year old flashlight that incorporates both a miniature  
incandescent bulb (like the #222 but rated at 4.8 volts) and 4" F4T5  
white fluorescent tube and uses 4 penlight batteries.  A 4" UV tube,  
F4T5/BLB can be substituted and then you have a small, portable UV  
source that also doubles as flashlight.  Don't know if what I have can  
still be purchased (NOS perhaps).  Sincerely ,

--  
J. B. Wood                e-mail: arl snipped-for-privacy@hotmail.com

Re: black light
On 11/02/19 22:53, snipped-for-privacy@gmail.com wrote:
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Well over 50 years ago I bought an ex-WW2 aircraft "blacklight",  
possibly from a Lancaster. It was on flying leads, with a black-painted  
metal body about a couple of inches in diameter and long. Inside was a  
small filament bulb (I can't remember the voltage - possibly 12?). The  
front was a domed, very dark violet glass. When the bulb was on, you  
could just about see the filament in a dark room. I also had a couple of  
instruments from a WW2 plane. Both had paint which glowed well in the  
dark under that blacklight.

See here <https://en.wikipedia.org/wiki/Blacklight#Uses about 3/4 of  
the way through.

--  

Jeff

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