What unit is used to express absolute underwater pressure?

What unit is used to express absolute underwater pressure?

• A. Bar
• B. Pounds per square inch
• C. Atmospheres absolute
• D. Kilopascals

Answer: (C)

Absolute underwater pressure is expressed in atmospheres absolute because it represents the total pressure you experience, which is the combination of the air above you and the water pressure. At the surface you’re about 1 atmosphere under, and for every 10 meters of depth the water adds roughly another atmosphere. So the total pressure at a depth is described as a number of atmospheres absolute (atm abs). Other units like psi or kPa measure pressure, but they don’t inherently convey the “absolute” total pressure the diver feels unless you also specify abs, whereas atm abs is the standard way to state the full pressure experienced underwater.

Absolute underwater pressure is expressed in atmospheres absolute because it represents the total pressure you experience, which is the combination of the air above you and the water pressure. At the surface you’re about 1 atmosphere under, and for every 10 meters of depth the water adds roughly another atmosphere. So the total pressure at a depth is described as a number of atmospheres absolute (atm abs). Other units like psi or kPa measure pressure, but they don’t inherently convey the “absolute” total pressure the diver feels unless you also specify abs, whereas atm abs is the standard way to state the full pressure experienced underwater.