For accurate flow measurement of wastewater, sludge, slurries, chemicals, and abrasives, PDFM 5.1 employs Doppler signal processing with ability to filter out noise. Product shows flow rate instantly once ultrasonic sensor is mounted on outside of metal or plastic pipe and can be used for flow troubleshooting, spot checks, or balancing flow. After operator enters pipe diameter, unit will display, totalize, and log data in choice of gallons, liters, or any other engineering units.