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.
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The basic formula is:
Current Atmospheric Pressure x Max. Rated Level
of a Vacuum Pump
29.92" 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 to correct for 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.
Hg |
-mbar |
Torr |
-mm
Hg |
%
Vacuum |
| 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 |
Click here for a conversion table of the
above and other common units of measure:
Conversion Calculators
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applications engineers are always available to assist you in selecting the right
vacuum lifter. Call or e-mail us for
assistance.
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