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Mercury free HPS Happy New year and I’ll start it off with this HPS comparison. These are both 250w high pressure sodium lamps the upper one is an old used Sylvania SON/T lamp. While the lower is a new Philips, mercury free version. The arc tube in the mercury free lamp is longer and thinner and I think this is due to the lamp parameters having more xenon and no mercury. Comparing the light output demonstrates how little the mercury adds to the discharge once fully lit. Keywords: Lamps

Mercury free HPS

Happy New year and I’ll start it off with this HPS comparison. These are both 250w high pressure sodium lamps the upper one is an old used Sylvania SON/T lamp. While the lower is a new Philips, mercury free version. The arc tube in the mercury free lamp is longer and thinner and I think this is due to the lamp parameters having more xenon and no mercury. Comparing the light output demonstrates how little the mercury adds to the discharge once fully lit.

SON60.JPG SON_T_Hg_free.jpg PH_SON_1k.jpg DSC_7596.JPG series.jpg
Lamp/Fixture Information
Manufacturer:Philips, Sylvania
Model Reference:SON/T
Lamp
Lamp Type:HP sodium
File information
Filename:SON_T_Hg_free.jpg
Album name:Tuopeek / High Pressure Sodium
Keywords:Lamps
Filesize:133 KiB
Date added:02 Jan 2025
Dimensions:1400 x 1063 pixels
Displayed:171 times
DateTime Original:2025:01:01 15:19:40
Exposure Time:1/500 sec
FNumber:f/11
File Source:Digital Still Camera
Flash:No Flash
Focal length:32 mm
ISO:100
Model:NIKON D3400
Software:Adobe Photoshop Elements 2.0
White Balance:0
URL:https://trad-lighting.net/gallery/displayimage.php?pid=623
Favourites:Add to Favourites

Comment 1 to 6 of 6
Page: 1

Sammi   [Thu 02 Jan 2025 at 19:30]
Nice to see, and a Happy New Year to you. Love
Max   [Fri 03 Jan 2025 at 11:11]
Happy new year! The difference in light output between various kinds of HPS lamps of same wattage may not seem significant to the naked eye or to the camera, but it is very real to the point that it actually caused the demise of the the Hg-free sodium lamps (the mercury-containing super HPS lamps being significantly more efficacious).
Ria   [Fri 03 Jan 2025 at 13:06]
I've honestly never understood the obsession with getting rid of mercury in all its forms at any cost. The amount in a lamp is trivial and even if you broke a case of them you wouldn't ingest any more mercury than by eating a plate of tuna (can't stand the stuff myself, but you get the picture..!)
Tuopeek   [Fri 03 Jan 2025 at 14:07]
Good points Max, thanks. Doesn't help that I am comparing a lamp from the early 90s with a significant number of hours against a new lamp. Not too surprising they appear similar, but I'm sure would be different if measured. I actually took images of the spectrum of both lamps, I must look at them closely for differences.

Ria, I remember my mother saying you could buy mercury to play with when she was young. I lost about a cubic cm of some mercury in my room growing up and never saw it again, don't think it was a problem. Laughing
Ria   [Fri 03 Jan 2025 at 18:50]
You could, I had a jar of it I got from an army surplus store around 30 years or so ago..! I still have a few teeth with amalgam fillings, I remember the dentist had a little dropper bottle of mercury he mixed with something to make the filling material. How times have changed Laughing
Tuopeek   [Fri 03 Jan 2025 at 20:20]
They were using it in tooth filling amalgams until recently, they don't recommend removing them either.

Comment 1 to 6 of 6
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