A few of these have started to appear near me. They've replaced the old
low pressure sodium street lights with compact fluorescent - have these
got massively more efficient in recent years? Last thing I knew compact
fluorescent was still a long way behind low pressure sodium.

Ben formulated the question :
A few of these have started to appear near me. They've replaced the old low
pressure sodium street lights with compact fluorescent - have these got
massively more efficient in recent years? Last thing I knew compact
fluorescent was still a long way behind low pressure sodium.

Are you sure they are compact flourescents? More likely they will be
high pressure sodium which is much less yellow than the low pressure.

--

Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

Harry Bloomfield wrote:
Are you sure they are compact flourescents? More likely they will be
high pressure sodium which is much less yellow than the low pressure.

In daylight when they are switched off its clear to see that they are
fluorescent, the fairly long stick type like the household ones were a
number of years ago before they made them shorter. At todays lengths I'd
estimate they are about 50W.

In article ,
Ben writes:
Harry Bloomfield wrote:
Are you sure they are compact flourescents? More likely they will be
high pressure sodium which is much less yellow than the low pressure.

In daylight when they are switched off its clear to see that they are
fluorescent, the fairly long stick type like the household ones were a
number of years ago before they made them shorter. At todays lengths I'd
estimate they are about 50W.

It's possibly a 55W folded compact fluorescent. They're probably
around 550mm long (designed to fit in 600mm module ceiling units).
Control gear is separate.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

Andrew Gabriel wrote:
In article ,
Ben writes:
Harry Bloomfield wrote:
Are you sure they are compact flourescents? More likely they will be
high pressure sodium which is much less yellow than the low pressure.
In daylight when they are switched off its clear to see that they are
fluorescent, the fairly long stick type like the household ones were a
number of years ago before they made them shorter. At todays lengths I'd
estimate they are about 50W.

It's possibly a 55W folded compact fluorescent. They're probably
around 550mm long (designed to fit in 600mm module ceiling units).
Control gear is separate.


It's certainly folded, but I don't think its as long as 55cm, more like
half that I'd say. I have the impression that they've got 2 folded
loops, just like the CFLs you buy in the shops to replace incandescents,
but I'll have another look to check that. The lamp posts on a whole
street have now been replaced with new ones, the heads look the same as
the few individual ones that I've seen near me, but I don't know if
they're wired up yet (the old posts are still there) and I haven't had a
look at the bulbs, if they've even fitted any yet.

In article ,
Ben writes:
A few of these have started to appear near me. They've replaced the old
low pressure sodium street lights with compact fluorescent - have these
got massively more efficient in recent years? Last thing I knew compact
fluorescent was still a long way behind low pressure sodium.

If efficiency was the only concern, low pressure sodium would
still be used everywhere. Generally however, it's being slowly
retired. The lower powered low pressure sodium lamps are not
as efficient as the larger ones in any case, and there probably
isn't a large difference between them and compact fluorescents.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On Sun, 26 Aug 2007 19:36:46 +0100 someone who may be Ben
wrote this:-

A few of these have started to appear near me.

How do you know they are compact fluorescent?

They've replaced the old
low pressure sodium street lights with compact fluorescent

Generally low pressure sodium street lights are being replaced by
high pressure sodium, which these days gives almost as white a light
as mercury lights (also called fluorescent lights).

The high pressure lamps are not as efficient as the low pressure
ones, but the light colour is a lot better.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

On Sun, 26 Aug 2007 20:17:06 +0100, David Hansen wrote:

On Sun, 26 Aug 2007 19:36:46 +0100 someone who may be Ben
wrote this:-

A few of these have started to appear near me.

How do you know they are compact fluorescent?

They've replaced the old
low pressure sodium street lights with compact fluorescent

Generally low pressure sodium street lights are being replaced by high
pressure sodium, which these days gives almost as white a light as mercury
lights (also called fluorescent lights).

The high pressure lamps are not as efficient as the low pressure ones, but
the light colour is a lot better.

==================================
A reflection on our changing world. The yellow sodium lights were
introduced (in part) because the yellow light was better able to
penetrate the smogs of the 1940s and 1950s.

Cic.

--
===================================
Using Ubuntu Linux
Windows shown the door
===================================

"Cicero" wrote in message
news
==================================
A reflection on our changing world. The yellow sodium lights were
introduced (in part) because the yellow light was better able to
penetrate the smogs of the 1940s and 1950s.

I think you will find that's a myth.. there is little evidence that yellow
light penetrates fog any better than white light does.
If different coloured light did penetrate fog better then all lights would
appear to be colored in fog.. which they do not.

On Sun, 26 Aug 2007 21:08:14 +0100, dennis@home wrote:


"Cicero" wrote in message
news
==================================
A reflection on our changing world. The yellow sodium lights were
introduced (in part) because the yellow light was better able to
penetrate the smogs of the 1940s and 1950s.

I think you will find that's a myth.. there is little evidence that
yellow light penetrates fog any better than white light does. If
different coloured light did penetrate fog better then all lights would
appear to be colored in fog.. which they do not.

==================================
Smog - not fog.

Smog was the name invented for the combination of heavy air pollution
(from coal fires etc.) and fog. Any one who lived through the great smogs
of the mid 20th century will remember road junctions marked by flaming oil
lamps because the white lights of the time were totally ineffective. Myth
or not, sodium lamps were considered to be the answer at the time. Fog is
basically white - smog was dirty yellow / brown and almost opaque.

Cic.

--
===================================
Using Ubuntu Linux
Windows shown the door
===================================

==================================
Smog - not fog.

Smog was the name invented for the combination of heavy air pollution
(from coal fires etc.) and fog. Any one who lived through the great
smogs
of the mid 20th century will remember road junctions marked by flaming
oil
lamps because the white lights of the time were totally ineffective.
Myth
or not, sodium lamps were considered to be the answer at the time. Fog
is
basically white - smog was dirty yellow / brown and almost opaque.

ISTR learning that sodium street lights were first used commercially in
the Netherlands where Philips developed them; and then in the UK on the
Purley Way near Croydon Aerodrome in the early 1930s. That wd be an
exceedingly odd place if their purpose was to counter the effects of
smog. Also the output from gas lamps of the kind common in London was,
according to my quondam tutor, often pretty much yellow (with the
mantles in use at the time) in any event. OTOH I can well believe that
their introduction was spun with any argument against those who hated
their colour.

--
Robin

On Sun, 26 Aug 2007 19:35:43 GMT, Cicero
wrote:

On Sun, 26 Aug 2007 20:17:06 +0100, David Hansen wrote:

On Sun, 26 Aug 2007 19:36:46 +0100 someone who may be Ben
wrote this:-

A few of these have started to appear near me.

How do you know they are compact fluorescent?

They've replaced the old
low pressure sodium street lights with compact fluorescent

Generally low pressure sodium street lights are being replaced by high
pressure sodium, which these days gives almost as white a light as mercury
lights (also called fluorescent lights).

The high pressure lamps are not as efficient as the low pressure ones, but
the light colour is a lot better.

==================================
A reflection on our changing world. The yellow sodium lights were
introduced (in part) because the yellow light was better able to
penetrate the smogs of the 1940s and 1950s.

An advantage of sodium is that it has an (almost) single chromatic
line, thereby reducing chromatic aberration, benefitting some people.

--
Frank Erskine

In article ,
Cicero wrote:
A reflection on our changing world. The yellow sodium lights were
introduced (in part) because the yellow light was better able to
penetrate the smogs of the 1940s and 1950s.

Bit of a myth. At one time car fog lights were yellow too. But that's gone
out of fashion.

Sodium street lights were 'yellow' because that was the extent of the
technology in those days for high efficiency lamps. They are diabolical
devices which make it impossible to tell the colour of a car or road sign
etc so were rightly superseded as soon as better technology became
available.

One interesting point is they prove we don't see colours as the same
within our brain. They are a narrow spectrum light and if an individual
matches what they see with wide spectrum light - ie a mixture of red green
and blue, they will get a totally different result from another. It's fun
to try. ;-) You can do it with a computer monitor.

--
*If a mute swears, does his mother wash his hands with soap?

Dave Plowman London SW
To e-mail, change noise into sound.

On Mon, 27 Aug 2007 10:33:15 +0100, Dave Plowman (News) wrote:

In article ,
Cicero wrote:
A reflection on our changing world. The yellow sodium lights were
introduced (in part) because the yellow light was better able to
penetrate the smogs of the 1940s and 1950s.

Bit of a myth. At one time car fog lights were yellow too. But that's gone
out of fashion.

Sodium street lights were 'yellow' because that was the extent of the
technology in those days for high efficiency lamps. They are diabolical
devices which make it impossible to tell the colour of a car or road sign
etc so were rightly superseded as soon as better technology became
available.

One interesting point is they prove we don't see colours as the same
within our brain. They are a narrow spectrum light and if an individual
matches what they see with wide spectrum light - ie a mixture of red green
and blue, they will get a totally different result from another. It's fun
to try. ;-) You can do it with a computer monitor.

==================================
Not entirely myth because it was the informed opinion at the time. All
those gadgets for car headlights (clip-on amber headlight lenses, amber
colour wash, etc.) really proved that there was very little
practical advantage in amber light over white light especially as you had
to remove them as soon as the fog / smog disappeared.

Colour perception is always a bit subjective, particularly in artificial
light. I believe it's a common shoplifter's defence -"I only wanted to
see how the diamond ring looked in daylight, Your Honour".

Cic.

--
===================================
Using Ubuntu Linux
Windows shown the door
===================================

Cicero wrote:
A reflection on our changing world. The yellow sodium lights were
introduced (in part) because the yellow light was better able to
penetrate the smogs of the 1940s and 1950s.

For years I've seen low pressure sodium lights defended on the grounds
that the human eye is more sensitive to that colour. All of a sudden,
light manufacturers are quoting new research that says it was all a big
mistake. The eye is only sensitive to that colour at bright light
levels, at low levels we are more sensitive to a bluish colour. It makes
sense, as light does go bluer at dusk so you'd expect our visual system
to be adapted to that. It does all rather give the impression though, to
me at least, of coming up with research to support whatever product you
want to flog at the time.

On Mon, 27 Aug 2007 12:04:09 +0100, Ben wrote:

Cicero wrote:
A reflection on our changing world. The yellow sodium lights were
introduced (in part) because the yellow light was better able to
penetrate the smogs of the 1940s and 1950s.
---------------------------------------------

For years I've seen low pressure sodium lights defended on the grounds
that the human eye is more sensitive to that colour. All of a sudden,
light manufacturers are quoting new research that says it was all a big
mistake. The eye is only sensitive to that colour at bright light
levels, at low levels we are more sensitive to a bluish colour. It makes
sense, as light does go bluer at dusk so you'd expect our visual system
to be adapted to that. It does all rather give the impression though, to
me at least, of coming up with research to support whatever product you
want to flog at the time.

==================================
I think I'll modify my original comment to,

"........the yellow light was *allegedly* better able to penetrate the
smogs of the 1940s and 1950s".

The truth is that we got much better street lighting after the war
(compared with pre-war lighting, rather than war time) so nobody was
too concerned about the details. The only real loss from the improvement
was that the old gas street lamps slowly disappeared and left post-war
children with no wickets for their cricket.

Cic.

--
===================================
Using Ubuntu Linux
Windows shown the door
===================================

David Hansen wrote:
On Sun, 26 Aug 2007 19:36:46 +0100 someone who may be Ben
wrote this:-

A few of these have started to appear near me.

How do you know they are compact fluorescent?

They've replaced the old
low pressure sodium street lights with compact fluorescent

Generally low pressure sodium street lights are being replaced by
high pressure sodium, which these days gives almost as white a light
as mercury lights (also called fluorescent lights).

The high pressure lamps are not as efficient as the low pressure
ones, but the light colour is a lot better.

I'm familiar with the difference in colour (and bulb appearance) between
low pressure and high pressure sodium. When switched off its clear to
see that these are fluorescent.

On Mon, 27 Aug 2007 11:59:54 +0100, Ben mused:

David Hansen wrote:
On Sun, 26 Aug 2007 19:36:46 +0100 someone who may be Ben
wrote this:-

A few of these have started to appear near me.

How do you know they are compact fluorescent?

They've replaced the old
low pressure sodium street lights with compact fluorescent

Generally low pressure sodium street lights are being replaced by
high pressure sodium, which these days gives almost as white a light
as mercury lights (also called fluorescent lights).

The high pressure lamps are not as efficient as the low pressure
ones, but the light colour is a lot better.

I'm familiar with the difference in colour (and bulb appearance) between
low pressure and high pressure sodium. When switched off its clear to
see that these are fluorescent.

I'm not convinced.
--
Regards,
Stuart.

Lurch wrote:
On Mon, 27 Aug 2007 11:59:54 +0100, Ben mused:

David Hansen wrote:
On Sun, 26 Aug 2007 19:36:46 +0100 someone who may be Ben
wrote this:-

A few of these have started to appear near me.
How do you know they are compact fluorescent?

They've replaced the old
low pressure sodium street lights with compact fluorescent
Generally low pressure sodium street lights are being replaced by
high pressure sodium, which these days gives almost as white a light
as mercury lights (also called fluorescent lights).

The high pressure lamps are not as efficient as the low pressure
ones, but the light colour is a lot better.
I'm familiar with the difference in colour (and bulb appearance) between
low pressure and high pressure sodium. When switched off its clear to
see that these are fluorescent.

I'm not convinced.

But high pressure sodium lights (I'm talking about the bulb appearance
when switched off) look nothing like compact fluorescents. If you have a
photo, perhaps from a manufacturer's or supplier's website then please
post a link. I'd prefer to be proved wrong sooner rather than later ;-)

On Mon, 27 Aug 2007 12:09:40 +0100, Ben mused:

Lurch wrote:
On Mon, 27 Aug 2007 11:59:54 +0100, Ben mused:

David Hansen wrote:
On Sun, 26 Aug 2007 19:36:46 +0100 someone who may be Ben
wrote this:-

A few of these have started to appear near me.
How do you know they are compact fluorescent?

They've replaced the old
low pressure sodium street lights with compact fluorescent
Generally low pressure sodium street lights are being replaced by
high pressure sodium, which these days gives almost as white a light
as mercury lights (also called fluorescent lights).

The high pressure lamps are not as efficient as the low pressure
ones, but the light colour is a lot better.
I'm familiar with the difference in colour (and bulb appearance) between
low pressure and high pressure sodium. When switched off its clear to
see that these are fluorescent.

I'm not convinced.

But high pressure sodium lights (I'm talking about the bulb appearance
when switched off) look nothing like compact fluorescents. If you have a
photo, perhaps from a manufacturer's or supplier's website then please
post a link. I'd prefer to be proved wrong sooner rather than later ;-)

A glass tube is a glass tube. You can't necessarily tell what the
actual lamp type is unless you can get a look at the control gear.
--
Regards,
Stuart.

On Mon, 27 Aug 2007 11:59:54 +0100 someone who may be Ben
wrote this:-

I'm familiar with the difference in colour (and bulb appearance) between
low pressure and high pressure sodium. When switched off its clear to
see that these are fluorescent.

I have seen plenty of fluorescent lamps in street lights. There was
once a fashion for linear tubes. More recently compact fluorescent
lamps have been used in the smaller road signs.

However there would be little if any advantage in using compact
fluorescent lamps in a street light compared to other forms of lamp.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

Ben wrote:

A few of these have started to appear near me. They've replaced the old
low pressure sodium street lights with compact fluorescent - have these
got massively more efficient in recent years? Last thing I knew compact
fluorescent was still a long way behind low pressure sodium.

There are white sodiums now.


NT

wrote:
Ben wrote:

A few of these have started to appear near me. They've replaced the old
low pressure sodium street lights with compact fluorescent - have these
got massively more efficient in recent years? Last thing I knew compact
fluorescent was still a long way behind low pressure sodium.

There are white sodiums now.

That's interesting, I didn't know that. These are definitely fluorescent
though. When switched off they look exactly like the ones you use at
home (except a bit longer, like they were a few years ago).

That's interesting, I didn't know that. These are definitely
fluorescent
though. When switched off they look exactly like the ones you use at
home (except a bit longer, like they were a few years ago).

Thanks for the excuse for some displacement activity.

It seems local authorities are now starting to use compact fluorescent..
Eg:

Blackburn http://www.blackburn.gov.uk/server.php?show=nav.293
Durham
http://www.durham.gov.uk/durhamcc/us...treet+Lighting
Wolverhamption
http://www.wolverhampton.gov.uk/NR/r...olicy926KB.pdf



--
Robin

Robin wrote:
That's interesting, I didn't know that. These are definitely
fluorescent
though. When switched off they look exactly like the ones you use at
home (except a bit longer, like they were a few years ago).

Thanks for the excuse for some displacement activity.

You're welcome, I'm full of them!

It seems local authorities are now starting to use compact fluorescent..
Eg:

Blackburn http://www.blackburn.gov.uk/server.php?show=nav.293
Durham
http://www.durham.gov.uk/durhamcc/us...treet+Lighting
Wolverhamption
http://www.wolverhampton.gov.uk/NR/r...olicy926KB.pdf

Well you can add our local authority to the list, especially if the
whole street full of lamp posts they've just replaced turn out to have
the compact fluorescent heads. I think I'll have a wonder over there
this evening and take a look.

In article ,
Ben wrote:
wrote:
Ben wrote:

A few of these have started to appear near me. They've replaced the
old low pressure sodium street lights with compact fluorescent - have
these got massively more efficient in recent years? Last thing I knew
compact fluorescent was still a long way behind low pressure sodium.

There are white sodiums now.

That's interesting, I didn't know that. These are definitely fluorescent
though. When switched off they look exactly like the ones you use at
home (except a bit longer, like they were a few years ago).

Aberdeen had fluorescent lighting for its main road - Union Street - in
the '50s. Each luminaire had about 10 4ft tubes.

--
*Work is for people who don't know how to fish.

Dave Plowman London SW
To e-mail, change noise into sound.

In article ,
"Dave Plowman (News)" writes:
Aberdeen had fluorescent lighting for its main road - Union Street - in
the '50s. Each luminaire had about 10 4ft tubes.

The larger streetlamp lanterns for fluorescent tubes were normally
5' 80W tubes. 4' 40W would have been too low powered. There were
2' 40W tubes for smaller lanterns for residential roads.

In a search for pictures, I found someone has created a catalogue
of historic streetlamps. Here are lots of fluorescent ones:
http://www.simoncornwell.com/lighting/ident/f1.htm

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

In article ,
Andrew Gabriel wrote:
In article ,
"Dave Plowman (News)" writes:
Aberdeen had fluorescent lighting for its main road - Union Street - in
the '50s. Each luminaire had about 10 4ft tubes.

The larger streetlamp lanterns for fluorescent tubes were normally
5' 80W tubes. 4' 40W would have been too low powered. There were
2' 40W tubes for smaller lanterns for residential roads.

Ah - right. Only a guess - I was little too then. ;-)

In a search for pictures, I found someone has created a catalogue
of historic streetlamps. Here are lots of fluorescent ones:
http://www.simoncornwell.com/lighting/ident/f1.htm

The Union street ones don't appear to be there. They were vertical and
mounted on buildings rather than posts.

--
*Do infants enjoy infancy as much as adults enjoy adultery? *

Dave Plowman London SW
To e-mail, change noise into sound.