Abstract: A flowmeter has a tank disposed between a discharge circuit and a supply circuit from which the tank is refilled when the level of the liquid in the tank falls below a predetermined level. A plunger is suspended in the tank by a force sensor. The output of the force sensor is used to measure the rate of flow from the tank to the discharge circuit except when the tank is being refilled. Flow from the tank during a refilling cycle is approximately measured in response to flow parameters in the discharge circuit which are independent of the force sensor and liquid level in the tank. The flow parameters in the discharge circuit are monitored and calibrated during each tank discharge cycle, and the new calibration values are used during the next tank refilling cycle, to obtain reasonably accurate continued flow measurement during each tank refilling cycle.