THE MOST USED PRESSURE UNITS IN THE REFRIGERATION MECHANIC AREA ARE:

Pounds per square inch - Pound per Square Inch (lbf / in2 or psi);
Bar (bar);
Inch mercury (inHg or "Hg);
Micra or Micron of Mercury (Hg);
Kilogram-force per square centimeter (kgf / cm2);
Atmosphere (atm);
Pascal (Pa);