CRT rebuilding as hobby?

[jr_tech]

Nice chart, Again 10 to the -6 is about what is needed to process a CRT, and simply put you can't get there with a simple mechanical pump such as those used to pump refrigeration systems. Most CRT processing stations use a diffusion pump, sometimes with a Ln2 cold trap.
Now the mechanical gauge on such a system *may indicate* a "perfect vacuum", but really it is not capable of making a precise measurement. It would sort of like trying to measure the speed of light with a stopwatch! A decent ion gauge is needed to measure high vacuum, *not* a barometer type mechanical gauge.
jr

Ion Gauge : http://en.wikipedia.org/wiki/Hot-fil...nization_gauge
Diffusion pump: http://en.wikipedia.org/wiki/Diffusion_pump

[snelson903]

after seeing the other types of vacuum pumps , i didnt know they could go that low to remove more than moister.

[bandersen]

10-6 torr is about 0.00000004 inches of Hg

[WA3WLJ]

Water boils at about 12 Torr at 74 Degrees F

[WA3WLJ]

Diffusion pumps get down to 5 X 10-8 or better at work , which is 200 times better than 1 X 10-6