Page 42 - Schmalz - Vacuum Components

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PA01019111_inh_EN.pdf
Vacuum Knowledge
Basic Vacuum Knowledge and Vacuum Terminology
PA01019111_inh_EN.pdf Definition of Vacuum PA01019111_inh_EN.pdf

Schmalz - The Company Vacuum is the term for air pressures which lie below normal atmospheric pressure. The ambient pressure is 1,013 mbar at sea level

and decreases with elevation.

Vacuum Knowledge The form of the vacuum depends on the application in vacuum technology. A relatively small vacuum, the low vacuum, is sufficient for
vacuum handling.
The pressure of the low vacuum ranges from 1 mbar to 1,013 mbar (ambient pressure at sea level).

Vacuum Suction Cups Specification as relative value
In vacuum technology, the vacuum is specified as a relative value which means the vacuum is specified in relation to the ambient
pressure. Such vacuum values always have a negative sign, because the ambient pressure is used as the reference point, which is
defined as 0 mbar.
Special Grippers -1,000 -500 0 Overpressure +1,000 mbar
Underpressure / Vacuum
+500
Vacuum Grip- ping Systems Ambient pressure

Specification as absolute value
In science, a vacuum is specified as an absolute value. The reference point is absolute zero, which means space void of air (e.g. outer
Mounting Elements space). This means the vacuum value is always positive.

0 +500 +1,000 mbar

Vacuum Generators Absolute value

The following table shows the comparison values between absolute and relative pressure.

Valve Technology Vacuum/pressure conversion table bar N/cm 2 kPa atm, kp/cm 2 mm H O Torr; mm Hg in Hg
Relative
Absolute pressure
2
[mbar] vacuum -0.101 -1.01 -10.1 -0.103 -1,030 -76 -3
Switches and Monitoring 800 20% -0.203 -2.03 -20.3 -0.207 -2,070 -152 -6
900
10%
-3,100
30%
-0.304
-228
-0.310
-30,4
700
-3.04
-9
600
-0.507
500 40% -0.405 -4.05 -40.5 -0.413 -4,130 -304 -12
-5.07
-0.517
-5,170
50%
-15
-50.7
-380
-6,200
-60.8
-18
-6.08
60%
400
Filters and Connections 300 70% -0.709 -7.09 -70.9 -0.723 -7,230 -532 -21
-456
-0.608
-0.620
-24
-8,270
-0.827
-0.811
80%
200
-81.1
-608
-8.11
100 90% -0.912 -9.12 -91.2 -0.930 -9,300 -684 -27
At the end of this chapter you will find additional conversion and unit tables.
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PA01019111_inh_EN.pdf