Auger fillers are used for powder or particulate products. The auger is a rotating screw in a cylindrical casing which delivers a fixed volume of product from the feed hopper to the container for each revolution of the screw. The rotation is detected by a shaft encoder connected to the drive shaft. Alternatively, a timer can control the volume of product delivered. A rotating agitator blade is often fitted in the hopper to ensure free flow of product into the screw. Auger filling units are also frequently used to fill containers in a weigh filler.