Difference between gauge pressure and absolute pressure measurement

Again and again, we have been asked the question about the difference between a complete pressure measurement and a gauge pressure measurement. To answer this question it helps to look at the definition of gauge pressure and absolute pressure. The difference between your two measurements is then explained relatively simply and therefore also the decision of the correct measurement.
Definition of absolute pressure
Absolute pressure is really a pressure that is in accordance with the zero pressure in the empty, air-free space of the universe. Euphoric is the ideal or absolute vacuum. It is denoted with the subscript ?abs?: Pabs.
Antagonistic of gauge pressure
The gauge pressure means the difference between a complete pressure (Pabs) and the prevailing atmospheric pressure (Pamb). It really is denoted with the subscript ?e?: Pe and is calculated as follows: Pe = Pabs ? Pamb.
Absolute vs gauge pressure measurement
The difference between your two measurements is relatively easily clarified: in a gauge pressure measurement, it is always the difference from the current ambient pressure that is measured. However, this pressure changes with the elements and the height above sea level. An absolute pressure measurement measures the difference from the perfect or absolute vacuum. Because of this , this measurement is independent of environmental influences such as weather or altitude. Which measurement is currently the right one?
In practice, the two measurements can be differentiated the following: typically, the measuring task would be to determine the gauge pressure. This is the reason this type of sensor is hottest. However, if a gauge pressure sensor can be used in an application where the actual measuring task would be to measure the absolute pressure, the next additional errors must be expected:
+/- 30 mbar caused by changes in weather
around 200 mbar when changing the location (e.g. from sea level to 2,000 m)
Depending on measuring range, these errors could be substantial (e.g. in pneumatics at a measuring range of 1 bar) or negligible (in hydraulics at 400 bar).
Note
For anyone who is uncertain whether your measuring task needs a complete pressure or gauge pressure measurement, simply e mail us ? we?ll be glad to work with you.

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