The Preso PTTF ultrasonic transit time clamp-on integral mount flow meter, from Preso Flow Metering Equipment, uses time of flight ultrasonic technology to measure most clean liquids containing moderate amounts of suspended solids or aeration. The unit features low-cost, easy installation by clamping on the outside of existing pipe systems ranging in size from 0.5 to two inches. Designed to replace mechanical flow meters in applications where liquid conditions tend to damage or impede flow meter operation, the Preso PTTF provide two flow rate outputs, 4-20 mA analog and a simulated turbine or TTL-pulse frequency output, as well as Windows®-based software to enable quick configuration, calibration and troubleshooting via a notebook PC.