A process used to determine the differential pressure

present within a liquid-filled space.

The formula for determining the differential pressure

within a wet leg design is: d/p = h (SG)

Where: d/p = differential pressure, h = height of liquid

present, and SG = specific gravity

When the process vapors condense at normal ambient

temperatures or are corrosive, this reference leg can be

filled to form a wet leg. If the process condensate is

corrosive, unstable, or undesirable to use to fill the wet

leg, this reference leg can be filled with an inert liquid.