27 Jul
2007
27 Jul
'07
11:04 a.m.
At 07:50 AM 7/27/2007, William Donzelli wrote:
The idea behind the getter is to clean up and gas that
might be
trapped in the metal elements during pumpdown. A getter is really not
to clean up gases that sneak in thru the glass metal seals - the
getters just are not that effective, and as any plumber will tell you,
leaks only get bigger.
Hmm, that reminds me of a lingering question in my mind.
As a kid, I remember harvesting tubes from dead TVs behind
the repair shop. Breaking the tube, there was often a ring
at the top, U-shaped in cross-section. I seem to remember
that they were filled with a powder that reacted with
water, fizzing. Am I mixing up this smell-memory with playing
with calcium carbide? What were common getter chemicals?
- John