The level of vacuum can be classified. The higher the vacuum the harder it is to achieve.
|
Torr (mm Hg)
|
Term
|
LOG10
|
|
759 to 1
|
reduced pressure
|
>= 0
|
|
0.999 to 0.001
|
low vacuum
|
< 0 to -3
|
|
0.00999 to 0.00001
|
medium vacuum
|
-3.001 to -5
|
|
0.0000099 to 10^(-9)
|
high vacuum
|
-5.001 to -9
|
|
< 10^(-9)
|
ultrahigh vacuum
|
< - 9
|
where:
• 1 atmosphere is 760 torr (mm Hg).
