Absoluttrycksmätning

Absoluttrycksmätning is a term in metrology that refers to the measurement of pressure relative to a perfect vacuum. Unlike gauge pressure, which measures pressure relative to atmospheric pressure, absolute pressure is the total pressure exerted by a system. This means that at zero absolute pressure, there is no matter and therefore no pressure.

In practice, achieving a perfect vacuum is difficult, but for most absolute pressure measurements, the residual pressure in the measuring instrument is negligible or accounted for. Absolute pressure is a fundamental quantity in many scientific and engineering applications, including meteorology, where atmospheric pressure is often reported as absolute pressure, and in processes involving gases or liquids where the total pressure is critical, such as in vacuum systems or fluid dynamics.

Several types of instruments are used for absolute pressure measurement. Barometers, for instance, are designed to measure atmospheric pressure as an absolute value. Other instruments include absolute pressure transducers that use diaphragms or other sensing elements whose displacement is proportional to the absolute pressure. These devices often incorporate a sealed reference vacuum chamber within the sensor itself. Understanding the difference between absolute and gauge pressure is crucial for accurate interpretation of pressure readings and for proper functioning of systems that rely on precise pressure control.