Last comment Click to see all comments made by Tuopeek 12/04/26 at 08:55Hmm, if you haven't added a compound then it is possible for the sodium to originate from the gas walls of the tube. This is noticeable when working with glass but the temperature need to be at the melting point I think. I could be released from an electrode coating but this is electrodeless and this would also give an indication to the location of the emitter. As it looks balanced here I still think it could be from the glass walls... Is that possible at low temperatures!