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Re: Spark Gap Gasses Experiment
"Hi Bert,
Since I am using glass as an enclosure, I don't want
to use hydrogen
because of the explosion hazard if I screw up :-)) It also
leaks very easily.
Once you use up the oxygen, then nitrogen is left.
However, nitrogen is
far from inert. It forms all kinds of chemical compounds
especially when
exposed to the extreme temperatures of arcs! Argon and
helium seem to be
the only reasonable and affordable gasses that are truly
inert. I do not
have a good source of helium, but if it were better, I could
always get a
bottle of it. It is amazing what a difference argon made in
gap burning.
The metal stays completely pure. "
The quenched gaps used in the old "wireless" days used
copper electrodes, typically round, and spaced of the order
of 0.010" apart. There was a recess in each ring around the
"working" electrode, and outside that was a fiber gasket
which sealed the inside of each individual gap (pair of
electrodes) so as to be air tight. As mentioned, the oxygen
was gone almost instantly, leaving an atmosphere which was
mostly nitrogen with a bit of argon. After many hours of
operation the gap surface would be clean and pink, although
VERY slightly pitted. I have such an old gap here, which
works great on a small coil and is NOISELESS(!) in
operation. I have taken it apart and find the electrodes
are indeed clean and pink after an hour or so of running.
Ed