How does Dalton’s Law of Partial Pressure apply to psychrometry?

Dalton’s Law states that in a mixture of perfect gases, each constituent behaves individually as if the others were not present. In psychrometry, this means that the total pressure of the air-water vapor mixture is the sum of the individual partial pressures of the constituents. This can be expressed mathematically as p_total = p_air + p_water_vapor. Dalton’s Law is essential in psychrometry as it allows us to calculate the properties of the mixture based on the properties of its individual components.