The DFM 5.1 Doppler Flow Meter from Greyline Instruments measures flow from outside a pipe. It uses Doppler signal processing for fast, clean processing, greater data resolution and an improved ability to filter out noise, which all combine to produce data accuracy. It mounts on any 1/2-inch I.D. or larger pipe and is designed for difficult liquids like wastewater, biosolids, slurries, abrasives or any liquid with bubbles or suspended solids. Calibration and startup is simple with the built-in five-button keypad. It has a large, backlit display and totalizer, isolated 4-20mA output and six control relays. Options include a built-in data logger and reporting system with USB output, Windows software and intrinsically safe sensor. 888/473-9546; www.greyline.com.