At flow rates greater than 0.5 ml/min, the displayed pressure is refreshed once per revolution of the pump drive. Since the revolution rate and thus the refresh rate is very low at flow rates of less than 0.5 ml/min, the refresh rate changes to multiple values per revolution. Therefore, the pulsation appears to increase at low flow rates. In reality, the pulsation remains constant, but it is displayed at a higher resolution at low flow rates.
