The AVFM 6.1 uses a submerged ultrasonic sensor to measure both Velocity and Level in the channel. The sensor is completely sealed with no orifices or ports. It mounts inside a pipe or at the bottom of a channel. Min, Max, and Total Flow data from the last 365 days is available on the LCD display, or download directly to a USB for easy reporting. At a glance, view flow rate, velocity, level, totalizer, relay status, and important diagnostic information on the LCD display as well. For more information, visit www.greyline.com.