compact fluorescent street lights

[Ben]

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.

[Lurch]

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

I'm not convinced.

[Ben]

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).

[Ben]

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 ;-)

[Robin]

Thanks for the excuse for some displacement activity.

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

Blackburn

[Lurch]

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

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.

[Cicero]

---------------------------------------------

================================== 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.

[Cicero]

---------------------------------

================================== Yes, each one had a horizontal bar just below the lamphead to rest the ladder against. And of course mugging hadn't yet become a national pastime so you only had to be able to see the next lamp to aim at when you were out walking with no fear of being robbed in the shadows.

Cic.

[Andrew Gabriel]

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.

[tony sayer]

They still have them down Barrow road in Cambridge!. And very pleasant they look too...

[David Hansen]

On Mon, 27 Aug 2007 09:54:40 GMT someone who may be Cicero wrote this:-

Possibly, though in this country only the banks are on holiday.

The subject is gas discharge lights. However, if you meant Victorian gas lights then I'm happy to take your word about the colour of light they produced.

[David Hansen]

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

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.

[Ben]

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.

[Ben]

Hmmm, I've been looking at supplier's websites and all the sodium tubes I've found have been clear glass and linear, not white phosphor coated glass and folded like CFLs. In the absence of anything else that looks like it, I still think its a CFL.

[Andy Hall]

Really? I'm on holiday and I'm not a bank.

That's true. The gas street lights where I was at the advent of natural gas were run on it for a short time. Town gas gave a more yellow light. With NG, the maintenance on the lamps became higher, I was told because they run hotter, and they were phased out for horrible electric ones.

[Andy Hall]

Whereabouts is that? I must take a look next time I visit Cambridge. Is it a conservation area?

[tony sayer]

Hope this link works!. It is in a number of roads off Trumpington road just north of Long road (closed at the moment because of the misguided bus)

Don't quite know, after all its in my backyard as it were!, if its a conservation area but its one of the most expensive areas of Cambridge. Houses there never seem to sell they are I believe handed down through the generations;!. Unless owned by the Uni or colleges.

a piccy of one here at Latham road just a little further north..

me a bell first we might meet up in a local to carry the aviation argument on .. or you could fly into Marshal's..

fact give us a wave, we're 2.8 Nautical miles South of the main runway, some interesting types overfly here from time to time;-)

[Cicero]

================================== In other words you didn't follow the thread.

Cic.

[David Hansen]

On Mon, 27 Aug 2007 15:04:18 GMT someone who may be Cicero wrote this:-

I perhaps didn't follow your sudden swerve. If you wish to feel superior about that then please do so.

[Ben]

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

Wolverhamption

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.