[??]??? ??

???(1atm or 760torr) ?? ?? ??? ???
????? ???.

??? ??
1. ??? (Low Vacuum)
: 760torr ~ 10-3torr
?? ???? ???? 99%? ??? ???
2. ??? (High Vacuum)
: 10-3torr ~ 10-7torr
3. ???? (Ultrahigh Vacuum; UHV)
: 10-8torr ??
??? ??? ???, ??????? ???
??????, ? ??? ??.


?? ???????? ?? ???? ???
1.2 x 10 -10torr? ???? ??.


??? ?? ? ?? ?? ?? : 1x10-13torr
??? ?? : 1x10-15torr ??.

??? ????
??, ??, ????, ????,
????, ????,???? ?

??? ??? ?? ???
??? ??? ?? ? ??

??? ??

atm (atmosphere ) 1?? = 1atm (? ???? ?? ??)
torr (Torricelli? ??? ?? ?? ; 1atm = 760torr (??? ?? ??)
mmHg (?? torr = mmHg ?? ??? ??? ??)
(torr = mmHg ? ?? 0¡æ ?)
1atm = 760mmHg = 10332 mmH2O (0¡æ ? ??)
psi (pound per square inch) 1atm = 14.7psi (????? ?? ??)
Pa (pascal) = 1 kg/ms2, 1atm = 101,325 Pa (1m2? ??? 1N? ?? ??? ?? ??? 1Pa)
hPa (hectopascal) = 100Pa, 1atm = 1013.25 Pa (????? ?? ??)
bar = 100,000 Pa, 1atm = 1.01325 bar
kgf/cm2 =(kgf : kilogram force, 1 kg? ??? ??? ?? ???? ???
???? ???? ??? ?? ??), 1 kgf/cm2 = 1cm2? ??? 1kg?? ??? ??
1atm = 1.033 kgf/cm2