www.soxlamps.com by Matthew Eagles

A website celebrating the low-pressure sodium lamp or SOX lamp (or LPS lamp in USA, Canada, Australia & New Zealand). Welcome!
 Homepage über SOX Lampen (Natriumdampf - Niederdrucklampen). Wilkommen!
 Site de lampes à vapeur de sodium basse pression. Bienvenue!
Welkom op deze website over SOX lagedruk natriumlampen!
Дoбpo пoжaлoвaть нa caйт нaтpиeвoй лaмpы низкoгo дaвлeния!

Animation (top left): A SOX lamp warming up from 0 to 7 mins. Each picture frame is taken 20 seconds apart. The lantern is a 90-watt GEC Z9454. Below: a SOX lamp (Thorn Beta 5, 35-watt) in Wrexham, U.K., 2004.

Welcome to www.soxlamps.com. Low-pressure sodium lamps have been used in streetlighting in the United Kingdom and in various places around the world since the 1930s. Many areas of the UK still use SOX lighting. With a distinctive deep yellow light, SOX lights are the most energy-efficient light sources. (citations below)

I am Matthew Eagles of Wrexham, U.K. I have put together this website for anyone who is interested in this subject area, even if it is just a passing interest. Most people in the UK will be familiar by sight with the type of streetlight pictured above but will have no idea how these lights work. I've been fascinated by them ever since I was a small boy.

This website was launched in November 2005 and the number of visitors has steadily risen over time. Initially I thought that only people in the UK would be interested in this site, but I have had comments from all over the world!

SOX lanterns are now in decline in nearly all areas in the UK and are being replaced with other lights that give a whiter colour of light. However, SOX lights require less energy and give out more light than many white-light sources. They are being replaced in the UK and elsewhere with lamps that have a higher wattage and less light output. Although all types of streetlight have their merits, there is unfortunately some misinformation circulated about SOX streetlighting (in the UK at least), especially in terms of their efficiency. This website indicates the many benefits of this type of light source. Unfortunately, in order to reduce costs in the last few years, it was deemed necessary to cut corners in the manufacture of SOX tubes which subsequently made them less reliable; a good-quality SOX lamp will last for years. Although the manufacturing processes have recently been improved again, the reputation of SOX has suffered somewhat.

Of the SOX lanterns that do get taken down, a fraction of them do go into the hands of enthusiasts and collectors, and there are probably several hundred such collectors in the UK.

* As a technical point: there are other historical types of low-pressure sodium lamp that work exactly the same as SOX, namely SLI and SO. But nearly all low-pressure sodium lamps that are on Britain's roads today are SOX (the term "SOX" has been around since the 1960s) and in order to keep things simple I have just used the term "SOX" in this website!

"As seen on TV" - here is a link to my 2007 appearance on BBC Wales Today in the U.K.: (click here - BBC website. The video may not work for everyone.)

Citations: The following publications/documents refer to SOX (low-pressure sodium) lighting as being the most energy-efficient light source. This holds true in all conditions unless light levels are extremely low, i.e. well below the level of general illumination normally experienced in a town or village at night.
"Low-pressure sodium discharge lamps" (J. W. Denneman, Ir.), IEE PROC., Vol. 128, Pt. A, No. 6, September 1981.
"Master SOX (-E) PSG" data sheet, Philips Lighting (click here to link to site)
http://webexhibits.org/causesofcolor/4.html
http://www.lamptech.co.uk/Documents/SO1%20Introduction.htm (James Hooker, Sylvania)

© Matthew Eagles 2005-2010. Last modified 10th March 2010.
Contact:

Please contact me with any feedback — good bits, bad bits, links to other sites etc!
I currently work for Glyndŵr University, Wrexham, U.K. However, this website is not associated with Glyndŵr University or any other organisation. It is provided for information and reference only — it is not a commercial site.

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This website was created on the Internet on 10th November 2005.
Updates since December 2006: