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Maybe and maybe not. PSIA makes it explicit that the measurement given is an "absolute" value; that is, its zero point is a complete vacuum. PSI may be absolute, or it may be given relative to ambient atmospheric pressure.
The difference between Absolute Presure and Gauge Pressure is 14.7psi. So zero gauge pressure (0psig) = 14.7 psia. 600 psig = 614.7 psia. Calibrate the tranmitter so 4mA is obtained at 14.7 psig and 20mA is obtained at 614.7psig. The span will be 600 psi in both cases.
hydrostatic pressureP= hdgwhere;p= pressure (N/m2 or Pa)h=height (m)d= density (kg/m3)g= acceleration due to gravity(9.81 m/s2)e.g.example problem.a pressure gage register 40 psig in a region where the barrometer is 14.5 psia. fine the absolute pressure in psia., and kPa(KN/m2)give.Pg= 40 psiaPo= 14.5 + 40p=54.5b. P=54.5psia=54.5 lb.....6894.8 N/m2In2 1 psi=37576606 N/m2375.77 KNp= 375.77 KPa
At this condition the compressibility factor will approximately be 1.03936 This shows that the air will behave al most as an ideal gas at very high pressure
Btu / scf = Btu / lb X MW / 379.5 where: MW = molecular weight of the gas, lb / lb-mol The constant 379.5 is the molar volume at standard conditions of 14.696 psia and 60°F