What is the primary use of a psychrometer by refrigeration engineers?

A psychrometer is an instrument specifically designed to measure the relative humidity of the atmosphere using two thermometers: one is a dry bulb that measures air temperature, and the other is a wet bulb that is moistened and used to measure the cooling effect of evaporation. The difference in readings between the two thermometers allows engineers to calculate the relative humidity.

In the context of refrigeration engineering, understanding the relative humidity is crucial because it influences the cooling efficiency of systems, the choice of refrigerants, and the overall comfort levels in climate-controlled environments. Proper management of humidity is especially important in commercial and industrial refrigeration applications, where moisture levels can affect both product quality and system performance.

The other choices, while relevant to different aspects of refrigeration and HVAC, do not pertain to the primary function of a psychrometer. Therefore, the focus on relative humidity as measured by a psychrometer highlights its essential role for refrigeration engineers.