Choose a pair of tissue types from the drop-down menus. Then enter the desired TR. The graph will show the relative signal intensities (SI) for each value of flip angle from 0-90 degrees. The Ernst angle, at which the maximum SI occurs, is shown in the table. The behaviour illustrated is typical for spoiled gradient echo (T1-weighted) sequences. The generator works best on a computer or a tablet with keyboard.
More about Gradient Echo here.