The Effect of Atmospheric Pressure on Vacuum Level
The Possible Vacuum Attained is based on your Altitude. Basically, The higher you are, the less vacuum you can attain. Current Atmospheric Pressure x Max. Rated Level of a Vacuum 30″ Hg = absolute vacuum
It is important to consider the relationship between atmospheric pressure and altitude as it affects vacuum pump performance. Because free air is less dense at higher altitudes (i.e. lower atmospheric pressure) operation at these higher altitudes has the effect of reducing the capacity and maximum vacuum levels attainable. In general flow is not affected, just the maximum vacuum level attainable.
Refer to the following table for correct vacuum pump performance at various altitudes.
Vacuum Gauge Reading When Read at Altitude
|
Altitude Above Sea Level (feet) |
Altitude Above Sea Level (meters) |
Atmospheric Pressure (psi) |
Maximum Vacuum Level Attainable (inches Hg) |
Vacuum Level Loss at Altitude |
Maximum Vacuum Level Possible at this Altitude |
|
0 |
0 |
14.70 |
29.921 |
– |
– |
|
1000 |
305 |
14.16 |
28.9 |
3.4% |
96.6% |
|
2000 |
610 |
13.66 |
27.8 |
7.1% |
92.9% |
|
3000 |
914 |
13.16 |
26.8 |
10.4% |
89.6% |
|
4000 |
1219 |
12.68 |
25.8 |
13.8% |
86.2% |
|
5000 |
1524 |
12.22 |
24.9 |
16.8% |
83.2% |
|
6000 |
1829 |
11.77 |
24.0 |
19.8% |
80.2% |
|
7000 |
2134 |
11.33 |
23.1 |
22.8% |
77.2% |
|
8000 |
2438 |
10.91 |
22.2 |
25.9% |
74.1% |
|
9000 |
2743 |
10.50 |
21.4 |
28.6% |
71.4% |
|
10,000 |
3048 |
10.10 |
20.6 |
31.3% |
68.7% |
|
11,000 |
3353 |
9.71 |
19.8 |
33.9% |
66.1% |
|
12,000 |
3658 |
9.34 |
19.0 |
36.5% |
63.5% |
|
13,000 |
3962 |
8.97 |
18.3 |
39.0% |
61.0% |
|
14,000 |
4267 |
8.62 |
17.5 |
41.4% |
58.6% |
|
15,000 |
4752 |
8.28 |
16.9 |
43.6% |
56.4% |
Conversion Chart
|
Pg-psig |
Pa-psia |
In. |
-mbar |
Torr |
-mm |
% |
|
0.00 |
14.70 |
0 |
0.00 |
760.0 |
0.0 |
0.0 |
|
0.49 |
14.24 |
1 |
33.86 |
734.6 |
25.4 |
3.3 |
|
0.98 |
13.75 |
2 |
67.72 |
709.2 |
50.8 |
6.6 |
|
1.47 |
13.26 |
3 |
101.58 |
683.8 |
76.2 |
9.9 |
|
1.96 |
12.76 |
4 |
135.44 |
658.4 |
101.6 |
13.2 |
|
2.45 |
12.27 |
5 |
169.30 |
633.0 |
127.0 |
16.5 |
|
2.95 |
11.78 |
6 |
203.16 |
607.6 |
152.4 |
19.8 |
|
3.44 |
11.29 |
7 |
237.02 |
582.2 |
177.8 |
23.1 |
|
3.93 |
10.80 |
8 |
270.88 |
556.8 |
203.2 |
26.4 |
|
4.42 |
10.31 |
9 |
304.74 |
531.4 |
228.6 |
29.7 |
|
4.91 |
9.82 |
10 |
338.60 |
506.0 |
254.0 |
33.0 |
|
5.40 |
9.33 |
11 |
372.46 |
480.6 |
279.4 |
36.3 |
|
5.89 |
8.84 |
12 |
406.32 |
455.2 |
304.8 |
39.6 |
|
6.38 |
8.35 |
13 |
440.18 |
429.8 |
330.2 |
42.9 |
|
6.87 |
7.86 |
14 |
474.04 |
404.4 |
355.6 |
46.2 |
|
7.36 |
7.36 |
15 |
507.90 |
379.0 |
381.0 |
49.5 |
|
7.86 |
6.87 |
16 |
541.76 |
353.6 |
406.4 |
52.8 |
|
8.35 |
6.38 |
17 |
575.62 |
328.2 |
431.8 |
56.1 |
|
8.84 |
5.89 |
18 |
609.48 |
302.8 |
457.2 |
59.4 |
|
9.33 |
5.40 |
19 |
643.34 |
277.4 |
482.6 |
62.7 |
|
9.82 |
4.91 |
20 |
677.20 |
252.0 |
508.0 |
66.0 |
|
10.31 |
4.42 |
21 |
711.06 |
226.6 |
533.4 |
69.3 |
|
10.80 |
3.93 |
22 |
744.92 |
201.2 |
558.8 |
72.6 |
|
11.29 |
3.44 |
23 |
778.78 |
175.8 |
584.2 |
75.9 |
|
11.78 |
2.95 |
24 |
812.64 |
150.4 |
609.6 |
79.2 |
|
12.27 |
2.45 |
25 |
846.50 |
125.0 |
635.0 |
82.5 |
|
12.76 |
1.96 |
26 |
880.36 |
99.6 |
660.4 |
85.8 |
|
13.26 |
1.47 |
27 |
914.22 |
74.2 |
685.8 |
89.1 |
|
13.75 |
0.98 |
28 |
948.08 |
48.8 |
711.2 |
92.4 |
|
14.24 |
0.49 |
29 |
981.94 |
23.4 |
736.6 |
95.7 |
|
14.70 |
0.00 |
29.92 |
1013.00 |
0.0 |
760.0 |
100.0 |