Constant Enthalpy Lines:
The enthalpy (or total heat) lines are inclined straight lines & regularly spaced as illustrated in given figure. These lines are parallel towards the wet bulb temperature lines, and are sketch up on the saturation curve. Some lines coincide with the wet bulb temperature lines also.
Constant Enthalpy Lines
The values of total enthalpy are provided on a scale above the saturation curve as illustrated in the given figure