Abstract: A fuel mass flowmeter 10 includes a rotatable drum 22 through which fuel to be metered may pass and an impeller 24 mounted within the drum such that it may rotate relative thereto but is biased against such rotation by a spring 26. The drum 22 may be rotated as fuel is passed therethrough, the passage of the fuel past vanes 36 on the impeller causing the impeller to rotate relative to the drum 22, the extent of rotation depending upon the mass flow rate. The rate of rotation of the drum 22 is measured and a correction factor is applied to the measured mass flow rate, the magnitude of the correction factor depending upon the rate of rotation of the drum 22.

Abstract: A fuel mass flowmeter 10 includes a rotatable drum 22 through which fuel to be metered may pass and an impeller 24 mounted within the drum such that it may rotate relative thereto but is biased against such rotation by a spring 26. The drum 22 may be rotated as fuel is passed therethrough, the passage of the fuel past vanes 36 on the impeller causing the impeller to rotate relative to the drum 22, the extent of rotation depending upon the mass flow rate. The rate of rotation of the drum 22 is measured and a correction factor is applied to the measured mass flow rate, the magnitude of the correction factor depending upon the rate of rotation of the drum 22.