2.1.2真空区域的划分 pressure (Torr) pressure (Pa) Atmospheric pressure 760 101.3kPa Low vacuum 760to25 100 kPa to 3 kPa Medium vacuum 25to1x103 3 kPa to 100 mPa High vacuum 1×10-3t01×109 100 mPa to 100 nPa Ultra high vacuum 1x109t01x1012 100 nPa to 100 pPa Extremely high vacuum <1×1012 <100 pPa Outer space 1x108to<3x10-17100Pat0<3Pa Perfect vacuum 0 0Pa 色子绅发女学 University of Electronic Science and Technology of China2.1.2真空区域的划分