So, what gas ionises with an intense and very 'clean' blue light ? A few of
these lamps have sprung up around my town. A couple light up some pieces of
art school stainles steel 'sculpture' in a local park. I hadn't taken too
much notice of them, until another example appeared on the top of a tall
pole, illuminating the vehicle compound of a premises on the same business
park as my wife's place is.

The lamp itself looks like a typical high pressure sodium type - basically
tubular with a bulge in the middle. But the light it gives off is an
extremely intense blue. What's in there, and what is the rationale behind
illuminating a compound with this colour ? Seems to chase off the shadows
pretty good, but I wouldn't have thought that it suited CCTV very well ?

Arfa

"Arfa Daily" wrote in
:

So, what gas ionises with an intense and very 'clean' blue light ? A
few of these lamps have sprung up around my town. A couple light up
some pieces of art school stainles steel 'sculpture' in a local park.
I hadn't taken too much notice of them, until another example appeared
on the top of a tall pole, illuminating the vehicle compound of a
premises on the same business park as my wife's place is.

The lamp itself looks like a typical high pressure sodium type -
basically tubular with a bulge in the middle. But the light it gives
off is an extremely intense blue. What's in there, and what is the
rationale behind illuminating a compound with this colour ? Seems to
chase off the shadows pretty good, but I wouldn't have thought that it
suited CCTV very well ?

Arfa




xenon? the xenon lamps for autos have a bluish tint.
and the extra UV might make a difference for the CCTV.

--
Jim Yanik
jyanik
at
localnet
dot com

On Sat, 10 Apr 2010 01:20:41 +0100, "Arfa Daily"
wrote:

The lamp itself looks like a typical high pressure sodium type - basically
tubular with a bulge in the middle. But the light it gives off is an
extremely intense blue. What's in there, and what is the rationale behind
illuminating a compound with this colour ?

It's suppose to prevent suicides and crime:
http://psychcentral.com/blog/archives/2008/12/13/can-blue-colored-light-prevent-suicide/
Maybe that's why I never committed any crimes while under a black
light. Or, maybe I was too stoned to do anything. Dunno.

Unfortunately, I can't determine what type of lighting is used. I
don't think it's LED or CFL but it's possible. It might also be a
mercury vapor arc lamp which belches lots of blue and UV. Google and
Bing won't tell me.

If you're into blue, here's a mess of nature photos in blue that are
suppose to be relaxing:
http://www.lifeinthefastlane.ca/natures-amazing-colors-what-blue-means/weird-science

It was Kmart that had a highly irritating "blue light special" and
BlueLight internet dialup service. Yech:
http://en.wikipedia.org/wiki/Kmart#Blue_Light_Special_and_1994_closures
Maybe it's Kmart coming back from the near dead?

--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831-336-2558
# http://802.11junk.com
# http://www.LearnByDestroying.com AE6KS

Arfa Daily wrote in message
...
So, what gas ionises with an intense and very 'clean' blue light ? A few
of
these lamps have sprung up around my town. A couple light up some pieces
of
art school stainles steel 'sculpture' in a local park. I hadn't taken too
much notice of them, until another example appeared on the top of a tall
pole, illuminating the vehicle compound of a premises on the same business
park as my wife's place is.

The lamp itself looks like a typical high pressure sodium type - basically
tubular with a bulge in the middle. But the light it gives off is an
extremely intense blue. What's in there, and what is the rationale behind
illuminating a compound with this colour ? Seems to chase off the shadows
pretty good, but I wouldn't have thought that it suited CCTV very well ?

Arfa



According to Brighton couincil , blue light in bogs stops junkies jacking
up, they can't find a vein.

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://diverse.4mg.com/index.htm

http://www.venturelighting.com/TechC...TechIntro.html

"[SMF]" wrote in message
...
http://www.venturelighting.com/TechC...TechIntro.html

This one is a possibility, but all other suggestions / guesses are basically
a "no". The lamp is definitely the sort of shape shown on this website, and
looking at their colour chart, I would estimate the colour temp of the lamps
in question to be around 6000k. Which is interesting, because this seems to
put them into the 'custom' bracket, normal stockers running out at the
blue-y end of white, which is the range of colour temps that we tend to see
these lamps in, in warehouses and suchlike.

So I wonder why they would be using a 'custom' (read expensive ?) lamp like
this for illuminating a vehicle compound ? I can understand the ones
lighting the stainless steel sculptures, as I guess this is what the artist
wanted.

Just so that everyone understands the sort of colour intensity we're talking
here, the light is not white tending towards blue - like the HID headlamp
suggestions made. Nor is it wishy washy blue-filtered white like you used to
see on emergency vehicles when they had blue plastic domes over white xenon
flash tubes. It's not the sort of intense blue that your eyes sometimes have
difficulty focusing on (we had a factory in our town that had its name on
the roof using internally lit blue plastic letters, and it was almost
unreadable). This light is of the same sort of general hue and intensity, as
the high visibility blue LEDs that they are now using on emergency vehicles.
But it is definitely not LED based - you can clearly see the dischage tube.
It is very 'clean' light, easy to look at. If you imagine the sort of light
that you get from the pale lemon high pressure sodium discharge lamps, and
then think blue instead, that's about as close a description as I can do.

Arfa

On Sat, 10 Apr 2010 12:32:42 -0400, Meat Plow wrote:

http://en.wikipedia.org/wiki/Metal_halide_lamp

Seems there are all sorts of different Halide combinations that affect
color.

I blundered onto this page of such lights:
http://www.lamptech.co.uk/MBI%20Quartz.htm
Each includes a color spectra graphs. Most are made to belch multiple
colors trying to simulate white daylight. However, this one:
http://www.lamptech.co.uk/Spec%20Sheets/Narva%20NC400-04.htm
shows a very blue/UV spectra. The bulb is for medical purposes, not
street lighting. However, it's the closest I could find to blue:

It is based on the NC400-64 blue coloured indium lamp, but
the dose chemistry has been modified to include the halides
of gallium and lithium. Gallium in particular adds a
strong blue and several UV peaks in the spectrum.



--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

"Jeff Liebermann" wrote in message
...
On Sat, 10 Apr 2010 12:32:42 -0400, Meat Plow wrote:

http://en.wikipedia.org/wiki/Metal_halide_lamp

Seems there are all sorts of different Halide combinations that affect
color.

I blundered onto this page of such lights:
http://www.lamptech.co.uk/MBI%20Quartz.htm
Each includes a color spectra graphs. Most are made to belch multiple
colors trying to simulate white daylight. However, this one:
http://www.lamptech.co.uk/Spec%20Sheets/Narva%20NC400-04.htm
shows a very blue/UV spectra. The bulb is for medical purposes, not
street lighting. However, it's the closest I could find to blue:

It is based on the NC400-64 blue coloured indium lamp, but
the dose chemistry has been modified to include the halides
of gallium and lithium. Gallium in particular adds a
strong blue and several UV peaks in the spectrum.



--
Jeff Liebermann


Good links, and also Meat's Wiki one. It's a far more interesting subject
than I had given it credit for ...

Arfa

In article ,
says...

So, what gas ionises with an intense and very 'clean' blue light ? A few of
these lamps have sprung up around my town. A couple light up some pieces of
art school stainles steel 'sculpture' in a local park. I hadn't taken too
much notice of them, until another example appeared on the top of a tall
pole, illuminating the vehicle compound of a premises on the same business
park as my wife's place is.

The lamp itself looks like a typical high pressure sodium type - basically
tubular with a bulge in the middle. But the light it gives off is an
extremely intense blue. What's in there, and what is the rationale behind
illuminating a compound with this colour ? Seems to chase off the shadows
pretty good, but I wouldn't have thought that it suited CCTV very well ?

If it's in a public park, why not check with your local park district or
whoever is in charge? They should know just what type of lights they
are, or at least who to ask.

--
If there is a no_junk in my address, please REMOVE it before replying!
All junk mail senders will be prosecuted to the fullest extent of the
law!!
http://home.comcast.net/~andyross