진공 Level별로 부르는 구간을 인용해 봅니다.  (Wikipedia 참조)

Pressure ranges of each quality of vacuum in different units
Vacuum quality                  Torr                              Pa                           (Atmosphere)

Atmospheric pressure         760 torr                     1.013×10^5 Pa
Low vacuum                      760 to 25 torr             1×10^5 to 3×10^3 Pa  (9.87×10−1 to 3×10−2 atm)
Medium vacuum            5 to 1×10−3 torr             3×10^3 to 1×10−1 Pa  (3×10−2 to 9.87×10−7 atm)
High vacuum              1×10−3 to 1×10−9 torr      1×10−1 to 1×10−7 Pa
Ultra high vacuum       1×10−9 to 1×10−12torr      1×10−7 to 1×10−10 Pa
Extremely high vacuum    < 1×10−12 torr             < 1×10−10 Pa             (< 9.87×10−16 atm)
Outer space            1×10−6 to < 1×10−17torr      1×10−4 to< 3×10−15 Pa  (9.87×10−10 to < 2.96×10−20 atm)