Abstract: Systems and related methods pump fluid through a pump having a stroke volume. The systems and methods employ gravimetric control measures to monitor fluid flow through the pump. An actuator interacts with the pump during a stroke interval (TStroke) to pump fluid through the pump. The systems and methods couple a receptacle to the pump, to either dispense fluid into the pump or to receive fluid from the pump. The systems and methods detect changes in weight of the receptacle over a sample time period. The systems and methods achieve a desired flow rate (QDesired) by deriving an actual flow rate (QActual) by sensing changes in weight of the receptacle over the sample time period, taking into account the density of the fluid, and adjusting the stroke interval based upon QActual so that QDesired is achieved.