Patent ID: 8573027

Claim:
A method of completing a metering cycle, comprising: positioning an actuation shaft of a flow metering device in a first position in a cavity for filling a flow metering device chamber in fluid communication with the cavity with a flow material; causing an aliquot of flow material to flow into the flow metering device chamber from a flow material reservoir through an input conduit and a proximal flow space defined by the cavity; positioning the actuation shaft in a second position in the cavity for dispensing the flow material from the flow metering device chamber, wherein the flow material reservoir is in fluid communication with the proximal flow space when the actuation shaft is in the second position such that the positioning of the actuation shaft to the second position causes a backstroke volume of flow material to flow from the proximal flow space into the flow material reservoir; observing the change in volume of the flow material in the flow material reservoir with data gathered from a sensor; and determining the backstroke volume.