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Exposed Arc Tube 70 SON-T
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Author:  Stelmer [ Thu Nov 19, 2009 7:28 pm ]
Post subject:  Exposed Arc Tube 70 SON-T

Ok, I broke one of my 70w SON-T lamps.

The arc tube is intact and still works though stays SOX orange as the outer vacuum is no longer present. Obviously it's not safe to use like this so what is the best method of disposing of it?

I was thinking of breaking the arc tube inside something and neutralizing the sodium but not sure if that is good due to the pressures.

Author:  Phosco152 [ Thu Nov 19, 2009 9:00 pm ]
Post subject:  Re: Exposed Arc Tube 70 SON-T

SON lamps contain very little sodium compared to SOX lamps. The term "high pressure sodium" is relative (compared to SOX) but actually it isn't very high. Lamptech quote 300 Torr for a Sylvania mercury free SON lamp from 1996. 1 Torr is 1/760 of an atmosphere so in effect the arc tube is at half atmospheric pressure - so in effect a vacuum anyway.

Most SON lamps also contain some mercury which can't be neutralised although the amount is really too small to be actually seen, its going to be milligrams.

I would keep it intact and put it in the fluorescent tube recycling bin at your local household waste centre.

For SOX lamps they can be broken in an empty bucket and water added from a hose at arms length to neutralise the sodium. When the fizzing stops pour away the water and the glass can be recycled in the normal way.

MBF lamps should go in the fluorescent lamp recycling bin.

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