System and Method for Measuring Fluid Drop Mass with Reference to Test Pattern Image Data

A method measures distances between two printed lines on a rotating image receiving member to identify fluid drop mass or fluid drop velocity changes in inkjet ejectors in an inkjet printing system. An initial distance between the two lines is measured at the start of the operational life of the system. During the line of the printing system, the lines are reprinted and the distance between the two lines compared to the initial distance. If the distance has changed by more than a predetermined amount, a firing signal for the printheads that printed the lines is adjusted.