Referring to the illustrated psychrometric chart, if the dry bulb temperature is 70F and the relative humidity is 40%, what is the absolute humidity? GS-RA-22

Illustration GS-RA-22: the U.S. Coast Guard has not released this illustration.

Question

Referring to the illustrated psychrometric chart, if the dry bulb temperature is 70F and the relative humidity is 40%, what is the absolute humidity? GS-RA-22

Illustration GS-RA-22: the U.S. Coast Guard has not released this illustration.

Accepted Answer

Option B: 45 grains of moisture per pound of dry air. Using a psychrometric chart, locating the intersection of the 70°F dry-bulb temperature line and the 40% relative humidity curve reveals the corresponding humidity ratio. At these conditions, the air contains approximately 45 grains of moisture per pound of dry air, a standard value for marine HVAC design and analysis.