Continuous velocity flowmeter logs are used to measure the fluid flow rates in open and cased wells. Logs can be run in the up or down direction; with or without the well producing water. Century's Impeller flowmeter uses a magnetic coupling between the sensing device and the electronics so that borehole fluids can not enter the tool and injected oil is no longer necessary. Internally, a 256-pulse-per-revolution optical encoder records the impeller turns minimizing statistical problems of other tools. With this low friction design low flow rates of less than 0.8 liters per second (3 gallons per minute). The tool is configured with a 114 mm (4.5 in.) shroud. 89 mm (3.5 in.) shroud is also available. Natural Gamma is optional.