Re: Somewhat off topic. Neon gas tubes..

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: d a <btoc3000@xxxxxxxxxxxx>

Sounds interesting. Anybody has a design plan for this?

I have a compressor ripped off from the fridge.

Thanks
sam

Tesla list <tesla@xxxxxxxxxx> wrote:
Original poster: Jim Lux

At 01:58 PM 10/2/2005, you wrote:
>Original poster: "Mercurus2000"
>
>I was just wondering, to make a neon light, all you really need is
>to pump a chamber down to several torr and then backfill fully till
>it's full with neon right?
>Adam

Gotta go lower than a few torr. You want a "glow discharge" not an
arc, so you need to be on the "vacuum" side of the "Paschen
minimum". Say, a few microns (0.001 torr) 1 torr = 1 mm of mercury.
1 micron = 1e-6 meter Hg. 760 torr = 1.013 bar 1013 mbar = 1013 hPa =
101.3 kPa. (nobody uses SI units for vacuum, so if you start asking
about pump ratings in Pa or mPa)

Also, unless you want to waste Ne (which is expensive), you want to
pump out substantially lower, otherwise whatever is in there mixes with the Ne.

The usual scheme is to pump down substantially below, fire the
getters, and run it really hot (with a "bombarder") to get the last
gases out. Then, you backfill with the desired gas.