rather than during normal ejection of ink from the nozzle fig1 shows an excitation time diagram that is applicable to effecting actuation of the actuator arm 28 and the paddle 27 from a quiescent to a lower than normal ink ejecting position the displacement of the paddle 27 resulting from the excitation of fig1 is indicated by the lower graph 42 in fig1 and it can be seen that the maximum extent of displacement is less than the optimum level that is shown by the displacement line 43 fig1 shows an expanded excitation time diagram that is applicable to effecting actuation of the actuator arm 28 and the paddle 27 to an excessive extent such as is indicated in fig8 and 9 the displacement of the paddle 27 resulting from the excitation of fig1 is indicated by the upper graph 44 in fig1 from which it can be seen that the maximum displacement level is greater than the optimum level indicated by the displacement line 43 fig1 16 and 17 shows plots of excitation voltage actuator arm temperature and paddle deflection against time for successively increasing durations of excitation applied to the actuating arm 28 these plots have relevance to fault detection in the nozzle device when detecting for a.