a device for measuring the volume of flow in a liquid conveying apparatus wherein the length and velocity of a liquid column are measured . drops of the liquid are formed and directed into a length of measurement tubing having a known internal diameter . as the liquid column is passed through the measurement tubing its length is determined by two spaced apart liquid sensors . the actual length is determined by calculating the time elapsed for the leading edge of the liquid column to interrupt the two liquid sensors . the time for the trailing edge to pass the first sensor is proportioned to the length of the column and the quotient of the two values will give the actual length . accordingly , accurate volume determinations can be made irrespective of velocity change such as due to viscosity , surface tension or back pressure . the device of this invention is especially adapted to be used in conjunction with an intravenous administration set .