The FlowTracker Handheld-ADV ® (Acoustic Doppler Velocimeter) measures 2D or 3D currents, attaches easily to wading rods, and features an automatic discharge computation using a variety of international methods, including ISO and USGS standards. The FlowTracker also features SonTek's exclusive "SmartQC" which involves a series of built-in data quality checks, so you know your data is right. At the end of the data run, just press a button and the FlowTracker calculates the discharge for you!