จำหน่ายเกจวัดแรงดัน Pressure Gauge ทุกยี่ห้อ

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Difference between gauge pressure and absolute pressure measurement

Again and again, we have been asked the question about the difference between an absolute pressure measurement and a gauge pressure measurement. To answer this question it helps to look at this is of gauge pressure and absolute pressure. The difference between your two measurements is then explained relatively simply and thus also the decision of the appropriate measurement.
Definition of absolute pressure
Absolute pressure is a pressure that is relative to the zero pressure in the empty, air-free space of the universe. This reference pressure may be the ideal or absolute vacuum. It is denoted with the subscript ?abs?: Pabs.
Definition of gauge pressure
The gauge pressure is defined as the difference between an absolute 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 the two measurements is relatively easily clarified: in a gauge pressure measurement, it will always be the difference from the current ambient pressure that’s measured. However, this pressure changes with the elements and the height above sea level. A complete pressure measurement measures the difference from the perfect or absolute vacuum. This is exactly why this measurement is independent of environmental influences such as for example weather or altitude. Which measurement is currently the right one?
In practice, the two measurements could be differentiated the following: in most cases, the measuring task is to determine the gauge pressure. That is why this kind of sensor is most widely used. However, if a gauge pressure sensor can be used in an application in which the actual measuring task is to measure the absolute pressure, the next additional errors should be expected:
+/- 30 mbar due to changes in weather
up to 200 mbar when changing the positioning (e.g. from sea level to 2,000 m)
Depending on the measuring range, these errors can be substantial (e.g. in pneumatics at a measuring selection of 1 bar) or negligible (in hydraulics at 400 bar).
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Should you be uncertain whether your measuring task needs a complete pressure or gauge pressure measurement, simply contact us ? we?ll be glad to work with you.