According to the SPE Metric Standard, the unit of pressure is the pascal, which is defined as one newton per square meter. “Use of the bar is discouraged by the standards organizations,” according to this standard.
One of the excellent recommendations in this document is to distinguish between absolute pressure (relative to vacuum) and gauge pressure
(relative to atmospheric pressure). This is frequently done when using customary units of pressure, such as psia and psig, but this is not done consistently when using metric units like kilopascals (kPa).
Here are some units of measure that “are to be avoided or abandoned,” according to the SPE Metric Standard:
• mm Hg
Profound Quote of the Day:
“Words differently arranged have a different meaning, and meanings differently arranged have different effects.”
– Blaise Pascal, French philosopher and scientist, 1623-1662