Vacuum Measurement

Vacuum

Vacuum units in the industrial manufacturing setting generally relate the internal gas pressure of a given chamber (tank) to the outside standard atmosphere. Gas will flow from higher pressure to lower pressure in an effort to equilize.

The website, The Engineering Toolbox, provides a useful reference table, replicated below, shows the relationship between various metrics for vacuum level measurement.

 

% Vacuum Torr (mm Mercury) Micron psia, (lb/in2 abs) Inches Mercury Absolute Inches Mercury Gauge kPa abs
0 760 760,000 14.7 29.92 0 101.4
1.3 750 750,000 14.5 29.5 0.42 99.9
1.9 735.6 735,600 14.2 28.9 1.02 97.7
7.9 700 700,000 13.5 27.6 2.32 93.5
21 600 600,000 11.6 23.6 6.32 79.9
34 500 500,000 9.7 19.7 10.22 66.7
47 400 400,000 7.7 15.7 14.22 53.2
50 380 380,000 7.3 15 14.92 50.8
61 300 300,000 5.8 11.8 18.12 40
74 200 200,000 3.9 7.85 22.07 26.6
87 100 100,000 1.93 3.94 25.98 13.3
88 90 90,000 1.74 3.54 26.38 12
89.5 80 80,000 1.55 3.15 26.77 10.7
90.8 70 70,000 1.35 2.76 27.16 9.3
92.1 60 60,000 1.16 2.36 27.56 8
93 51.7 51,700 1 2.03 27.89 6.9
93.5 50 50,000 0.97 1.97 27.95 6.7
94.8 40 40,000 0.77 1.57 28.35 5.3
96.1 30 30,000 0.58 1.18 28.74 4
96.6 25.4 25,400 0.49 1 28.92 3.4
97.4 20 20,000 0.39 0.785 29.14 2.7
98.7 10 10,000 0.193 0.394 29.53 1.3
99 7.6 7,600 0.147 0.299 29.62 1
99.87 1 1,000 0.01934 0.03937 29.88 0.13
99.9 0.75 750 0.0145 0.0295 29.89 0.1
99.99 0.1 100 0.00193 0.00394 29.916 0.013
99.999 0.01 10 0.000193 0.000394 29.9196 0.0013
100 0 0 0 0 29.92 0