Low pressure sodium?

strideredc

Enlightened
Joined
Dec 13, 2006
Messages
474
Location
UK
I was reading that these are the most efficient form of bulb?

Is there a form that's mag fitting size??? Sort of like that Welch and allen did with the 10w HID?

Anyone…
 
yeah!
you are right! these lams haven't got a good CCT but they are rated at 200 Lumns/Watt!!
I think I want a 10W lamp in my flashlight...:devil:
 
The smallest commercially available LPS lamp I've seen is 18 watts. I think it was about 2 and a 1/2 inches in diameter and around 10 inches long. The discharge tube was a smaller U shaped tube going through the length of the lamp. Not really a point source for throw but it will flood everything in a orange-yellow color that you shine it on.

How would you power it ?
Most LPS ballasts would probably run on 120volts AC so it will require a power inverter of some sort. There are a number of companies though that make DC LPS ballast for the renewable energy/solar powered outdoor lighting market though. Thin-Lite (who I am familiar with for fluorescent lights used in RV and Boat applications) has one. Search for the model LPS-118LT.

A LPS lamp will operate like HID; when turned on, it will take a few minutes to warm up to full brightness.
 
Last edited:
sodium lamps are cheap, efficient, and popularly used...but the tint isn't exactly very useable:ohgeez:....but much much better than whats emitted by mercury lamps:devil:
 
naaa, it would be like my mag just the second before it dies!!!

could be good for a camping lamp if it could be run off 4 d cells...???
 
do anyone know where can I found some of these sodium/mercury vapor lamps?

I have searched with google but I haven't found anything...:candle:
 
after a good search I've found a good place where to buy some HIGH pressuere sodium lamps...(in italy)
I think that they are pretty good efficent compared to a normal halogen lamp...I may probably buy one of these high pressure 400W sodium lamp and make an adaptator to fit it in a normal 220V spotlight that uses 500W tubolar halogen lamps...

-Osram 400W high pressure sodium lamp ---> 48000L
-Philips tubolar 1000W halogen lamp-------->26500L

:devil:
 
Finding low pressure sodium lamps (for a reasonable price) seems to be just about impossible. I've had it on my ebay watch list for a few years now and I'll occaisionally get hits on bulbs or very expensive fixtures but they are few and far between.
 
If you could get a common 590mm amber LED flashlight bulb, that's the same exact color.
 
I think LPS lamps emit mainly the sodium line at ~589.4nm - a very orangish-amber color.
And LPS bulbs have a very poor CRI (color rendering index)...the best thing about them is the very reddish neon glow (the gas fill is primarily neon & argon) they generate while in the earliest stages of their warmup cycle.
 
Compared to some LEDs the conversion efficiency isn't as good. The 180 LPS lamp gets 167 lm/W but 590 nm light has a luminous efficiency of 517 lm/W. Hence the efficiency is only 32%. If we could make a 590 nm yellow LED with efficiency on par with the best blue emitters (~50%), it would be in excess of 250 lm/W.

For now LPS is king of the hill but LED will soon surpass it, and with decent white light, not monochromatic yellow.
 
could be good for a camping lamp if it could be run off 4 d cells...???

could be good if you are completely color-blind. Really poor CRI reduces contrast and you need lot more light to be able to see as well as with white light source. Luckily lp-sodiums on streets are mostly replaced with hp-sodiums and mercury lamps.
 
The last time I saw LPS lamps in streetlighting was around 1981; they were found lighting the road near Floyd Dryden Jr. High school in Juneau AK. USA.
I saw one near the Greyhound bus depot in Portland OR. USA in late-May 2006; but I did not have my spectrometer handy at the moment. :green:
 
There is an LPS lamp on display at the Smithsonian Museum. They even have a diffraction lens to prove that it is a monochromatic light source.

I remember Southern California used LPS for street lighting in the past. Not sure if they still do. As a kid I was quite impressed by the long, sleek fixtures that looked so modern.
 
Massapequa Park, NY.

Also, in the late 70's; NYC began putting them on some streets, in industrial areas; and all along the Henry Hudson Parkway, stemming from Manhattan's West Side Highway. They also began appearing around some housing projects. This was the first time I had seen them; and with the recent rapid transition from mercury to hps fresh in my mind; I feared this would now be the next step.
But most of these have since been replaced with standard hps. You will occasionally still find a lps or two on a back street, and they are common on underpasses, and on high rise rooftops. Some of the river tunnels had them too (and it was amazing to be riding through, completely bathed in this light, and even a red shirt is now completely dulled down into almost nothing!). The tunnels now seem to have gotten halides and white SON's.
 
There is an LPS lamp on display at the Smithsonian Museum. I remember Southern California used LPS for street lighting in the past
:) lol, virtually all of the street lighting here is STILL low pressure sodium, known also as SOX,
as high pressure sodium is known also as SON
mercury MBF
metal halide HQI
i haven`t got a clue what the acronyms stand for though
 
Top