Rotating vane flowmeters have the rotor offset toward the bottom of the housing. Through this type of construction, larger volume areas are present at the top. As a result, large volumes of flow can be made to move across the top with little or no return through the bottom. These flowmeters are used in the petroleum industry to measure gasoline, crude oil, and low-viscosity fluids. Metering ranges are available from a few lpm or gpm to 25, 000 barrels per hour for crude oil metering. Accuracies of ±0.1 percent are typical, and values as high as ±0.05 percent are possible with larger instruments.